I think he is lucky to have those kids as well. My kids are not interested in these kind of experiments at all. Anyways it is good to do fun things together as a family
ME engineer here. Great work, indeed you are not increasing drag due to frontal area but you increase it due to a higher coefficient of drag, which is a linear increment, and because you are placing the turbine at the area where air is usually stagnated it really should not make much worse airdynamics. Your work is truly great, if you are able to recup 15% of lost energy that is going from 20 mpg to 23 mpg out of thin air. You may want to add deltas at the wing tips. You may be losing a portion of torque due to induced drag due to the AR of the blades. Great work, keep encouraging your children, it's awesome
My gut is that you're right and that further disrupting already turbulent air will show a net gain. But then again fluid dynamics is complicated and changing the flow of that air may have other, more complex effects on efficiency that are hard to predict. Either way I know that my maths isn't good enough to work it out, so I look forward to seeing the results!
Modern vehicle design tries to produce as little turbulence as possible, since turbulence results in higher drag, so my main thinking is that the fan, which creates turbulent air, is going to "undo" the aerodynamic design of the front end of the vehicle to some extent. This will be less impactful at slower speed, but at highway speeds aero drag becomes a much bigger component of efficiency, so I think it will come down to just how effectively the power generation can make up for it. The power required by the alternator is a small enough margin, that it could result in some gains at slower speeds, and some losses at higher speeds.
My feeling is that the power recovered will be inversely proportional to the drag coefficient of the vehicle. The higher the drag, the less power recovered. But that the additional fuel consumption will be directly proportional to the power recovered give or take efficiency. (would definitely prefer a brushless generator with bridge rectifiers) which may not may not offset the alternator load.
@@FlesHBoX⚠️ God has said in the Quran: 🔵 { O mankind, worship your Lord, who created you and those before you, that you may become righteous - ( 2:21 ) 🔴 [He] who made for you the earth a bed [spread out] and the sky a ceiling and sent down from the sky, rain and brought forth thereby fruits as provision for you. So do not attribute to Allah equals while you know [that there is nothing similar to Him]. ( 2:22 ) 🔵 And if you are in doubt about what We have sent down upon Our Servant [Muhammad], then produce a surah the like thereof and call upon your witnesses other than Allah, if you should be truthful. ( 2:23 ) 🔴 But if you do not - and you will never be able to - then fear the Fire, whose fuel is men and stones, prepared for the disbelievers.( 2:24 ) 🔵 And give good tidings to those who believe and do righteous deeds that they will have gardens [in Paradise] beneath which rivers flow. Whenever they are provided with a provision of fruit therefrom, they will say, "This is what we were provided with before." And it is given to them in likeness. And they will have therein purified spouses, and they will abide therein eternally. ( 2:25 ) ⚠️ Quran
@@FlesHBoXyeah. Drag on a vehicle is usually more laminar at the front and becomes progressively more turbulent as you get to the back. Which is part of why I think placing a turbine (probably a VAWT turned so it's axis of rotation is parallel to that of the rear wheels) where you'd place a spoiler would be best
I'm not an expert in aerodynamics, but AFAIK essentially the airflow generally "finds its way of least resistance" in order to "dodge out of way of the displacing car". Therefore, trying to "steal" the power from the way of that flowing air can only and merely increase its resistance (or worse yet disturb that path even more, making even more resistive path), equalling into increased drag on the car (as car needs to work harder to displace the air through more resistive/convoluted path). A more sensible idea might be to alter the pattern of airflow into more efficient in first place, using passive means (spoilers). On the other hand, wind turbines might have some use, if you could leave the airflow by the movement of the vehicle (mostly) untouched and instead utilize the natural wind. IIRC there do exist some kind of "turbine sailboats" working that way. For such setup, the best place might be on a tall enough wind tower on the roof. It could theoretically be simple and less or more usable if the wind turbine was the only power source, like in those experimental turbine sailboats. But due to its low efficiency, it might be impossible to sensibly combine it with any other power source, as it will also cause kinda threefold added drag against the power put on the motion by the other source than it provides, and it might be technically difficult to make it "ignore" the driving-induced airflow, which is usually the larger portion of the overall in case of road vehicle.
I don't even care about the tech, as a recent dad seeing you doing this with your kids brings a tear of joy to me eyes. I can only hope my kids grow up as excited to learn as yours. Congratz on your beautiful family @quint
I LOVE content like this. So many people assume they have all the answers figured out, but I love it when people actually put it to the test, and seeing your son get all into it all with you really makes me happy.
I love this channel and seeing your children get involved and learn has been the icing on the cake and every father's dream. That said, I suddenly see how your son's grown up, so it suggest you're not releasing nearly enough videos. Please remedy the issue. All the best
Instead of a electronic pitch control for the blades, maybe what you need is a Constant Speed Propeller system, that is used in small aircrafts. The difference will be just that your propellers are set to react to the wind, not try to use it to create thrust. The drive uses counter-weights to keep the propellers at a constant speed.
I love going down rabbit holes other people have never tried, you learn a lot even if it doesn't work out. I pulled the 3.1L V-6 out of my Cavalier while leaving the transaxle in, people said it couldn't be done. I even did it without an engine lift! Going back in, I put the clutch/ pressure plate on the input shaft of the transaxle before lowering the engine in. Once the engine was in and bellhousing bolts were installed/ torqued, I attached the pressure plate to the flywheel one bolt at a time through the starter opening as I rotated the engine 60° at a time. Then one more revolution to torque them. The best part was no clutch alignment tool was required, the actual input shaft did the job. Anyway, Newton's 1st law says you're not going to see any gains. In reality, you might see a small gain if your new charging system has much better efficiency... or you might see some loss. The torque required to turn the blades is countered by more "push" from the car which required more HP at the wheels. If your charging system efficiencies are the same, you'll see a decrease in MPG. Instead of the HP going directly to the alternator, your wind turbine will make the HP go through the powertrain which has inefficiencies in itself. While you're pushing the same air out of the way, the car now has to overcome the force (torque) required to rotate the turbine... see what Sir Isaac Newton says about a body at rest with a force acting on it. The force on the "body" (the wind turbine/ generator is at rest relative to the car) from the torque of the generator is opposed by an equal but opposite force from the car. You may see further losses due to disrupting the laminar air flow over the car. Thermodynamics/ entropy wins again... sorry. But I'm jealous that I didn't get to go down that rabbit hole with you. You're very fortunate to have those tools/ equipment and your children are very lucky to have you as a dad.
I'm glad to see you continuing to make videos😊. I hope you joy this idea for a relativly easy diy cheapest plugin hybrid. 1) Disconnect the car's electrical system from the alternator and battery. 2) Then run the car's electrical needs from 4 deep cycle batteries. And 3) use a battery charger to recharge them at home or on the road. That's the basic idea. 4) optionally: If one wants long range, then add battery capacity or plan to switch the alternator back when needed. Next level cheapest pluhin hybrid to replace the alternator with a 1kw motor. And use that to provide up to 1kw of mechanical power via the alternator belt. At this stage one probably wants to switch to Lithium based batteries for its energy density and longevity over lead acid. On difference between fan on top versus in front. By far this isn't a complete description of the difference but I hope it helps. 1st in front, the fan generator under load creates a high pressure pocket in front of the blades and low pressure pocket behind it. This pushes some of the air around the car creating an aerodynamic slip stream as the car drives in the wake behind the fan. obviously the benifits are canceled in large part by the electrical load on the turbine and the turbine being pushed by the car. If the car were not pushing the turbine, riding in the wake would be similar to practice of race cars traveling in the wake of a cars infront if it. Once when I had virtually no money for fuel and needed to go several hundred miles, I drove uncomfotably close behind tractor trailers using their wake and using the slip stream effect to improve my fuel econony. Maybe the tresulting turbulence down wind from the blades effects the car's aerodynamics. But the turbine's exhaust is slower moving and might not have as much drag on the car. Secondly, the air passing the turbin placed on top is slightly boosted by air speeding up as it goes over the top car. It might be easyer to generate power in faster wind, but there's no chance it could reduce drag on the car as there might be if placed in front.
Suggestion🗣❗️; I think you should explore different forms of wind turbines. One wind turbine I have in mind is the "Flying Clothesline" design because it can cover the entire frontal area of the car. Airloom modernized the design so take a look at theirs as well. Best of luck to your scientific journey🎉❤
To make it more streamlined, try enclosing the fan or multiple fans in a tube, simular to a jet fuselage & making the tube or multiple tubes along the car body
The car already uses the air in front of the car to cool the motor. So by that same principle, I feel a turbine in front should work (unless somehow it blocks the cooling of the engine and reduces its efficiency). Great video !
it is so weird seeing you drive around on roads that i know from when i lived in the area (still do, just a little farther away), and as a freshly graduated mechanical engineer, seeing these projects is just so much fun.
Here's that answer you requested: First, my background -- I'm 75 and have built wind turbines for about 55 years. Okay, the answer: A wind-tunnel simulation would clearly show the area in front of your vehicle COMPRESSES the airflow. A better turbine application (IMHO) would be to use a VAWT mounted horizontally either lower (if room allows) or higher at a point tangent to the radius of your car's hood. In either location. doing this places your wings directly WITHIN the airflow. Sidenote: I build small compressed-air operated engines as well as (mostly) VAWT wind turbines and all my windmills compress air whenever the wind blows in North Texas (24/7). If I decide to build the contraption, I'm describing here, I'll post a "build" video on my own TH-cam chanel.
I'm not a mechanical engineer, but from my electrical engineer perspective I can see two things: first, supposing there's no wind, the total power available is going to be equal to the force punching the turbine forwards times the distance it displaces per second, and the force is provided by the car. On the other hand, your argument says that wind speed will decrease as it passes through the turbine. Assuming 100% efficiency for the turbine, the air is going to be at rest after the turbine passes. So assuming 100% efficiency for the whole system there would be no difference with or without the turbine, right?, but staring from Betz's limit we can be pretty sure that's not going to happen. Greetings from Colombia. Your channel is great!
Would it not be a better use of the energy captured to have a battery bank and a small electric motor providing power to one or more wheels to drive the vehicle without the full use of the engine, basically a hybrid but using wind power to charge the the system.
I think the project is very interesting and I would like to see how it turns out. I agree with the comments that there are many challenges to overcome, but I think it is possible to make it work. I would focus on the following aspects: * The efficiency of the turbine: The turbine should be able to generate as much power as possible with minimal drag. * The reliability of the system: The system should be able to operate reliably in a variety of conditions, including high winds and rain. * The cost of the system: The cost of the system should be low enough to make it commercially viable. I think that if these challenges can be overcome, then wind power on vehicles could be a viable alternative to traditional engines.
This also can be used in a small unit in the front of an electric EV auto This will run a charging port to keep the EV so you can drive farther Being an engineer my self has talked to a few EV retailers but all said it will not work and understand bearable to look at I told them all this can be put under the front compartment that is used for almost nothing I love this this is a fabulous idea
Nice concept, here is two cents. The first issue addressed in aerodynamics is Frontal Area, a top mount will increase this area. While mounting props in front doesn't increase the area, it does make the prop less efficient due to back pressure, created by the car's nose. Beware of an uneven loads, due to such uneven pressures. Consider using a scroll or helix to drive the generator. Aligned in the vertical axis, has the potential of 'splitting the air', in a similar way water repellents are used in modern underwater bullets. Harvesting air flow from the rear deck lid (spoiler) has a potential to increase stability, and use the partial pressure created at the rear. Not an electrician, but disconnecting the battery can damage the alternator charging circuit. Which questions using super capacitors, due to low resistance (great for delivering starting amps). Good to see you recognize electricity generation is only 50% efficient, something the greeny idealist don't want known.
The turbine in front is where the air will be displaced anyway meaning it can’t be worse. If you put it on top of the car it will have a similar effect to what happens on a sail boat. It will catch air that is not doing work(as he mentioned) therefore increasing the amount of energy required by the car to keep moving. I look forward to the next video on this topic.
Love it! Maybe something like the Archimedes spiral/screw turbine blade might better capture the wind given the variability due to the cars aerodynamics...
Just a small word of concern... That tube mounting the turbine to the vehicle seems to be flexing dangerously close to the road when you hit bumps. I suggest you opt for a more rigid attachment. Watching the video I couldn't help but think "god if that tube hits something it might impale the cabin".
Let me give my two cents on the issue of the turbine on the roof vs the turbine on in front. At the end of the day, what matters is the drag on the car; that is what the motor is resisting. I think your van very clearly increases the drag of the car. It is just very much less tear drop aerodynamic with a spinning turbine in front. When it comes to aerodynamics, you want laminar flow, not turbulent flow. My worry is that not only does the turbine itself cause drag, but that the turbine also causes there to be less laminar flow over the body of the car. As someone who is a cyclist and knows the pain of being in the wind versus the relief of being in aerodynamic, my guess is that you end up costing more in drag from a loss of aerodynamics than you gain from the generator. The turbine on top is probably worse, for the reasons you give. The cross sectional area is just much larger. However, you do save the aerodynamic flow around the body of the car, but my guess is that the extra cross sectional area dominates there. Overall, turbine in the front is probably better than turbine on top, but no turbine is probably better than turbine in the front.
Yep, the turbine itself just freewheeling would add drag and mass to the car. Adding the draw from the generator will increase increase drag even more. No matter what, that energy is coming from the motor, all that has been added to the system is more drag, more mass, and the inefficiency of the generator converting kinetic energy to electricity. It's all waste energy. Even if the fan *somehow* made the system more aerodynamic, why attach the generator to it? The generator is just going to lose energy compared to the alternator taking the energy directly off the drive train.
So why not put the generators in the bed of a pick up truck towards the front? I remember an episode oh Mythbusters showing how the air swirls in your bed while the tail gate is up. Seems like that would be an ideal place for turbines without any extra drag on the vehicle. (obviously pickup only)
Not sure if this has been commented but if the turbine is on top, you're creating more drag because you're creating more wind resistance because of the total capacity breaking through the wind, not just the height of the car, then an additional two or three feet above the car, thus creating more drag. For the front of the car, could you get better wind turbine response if your wind turbine was set up similar to that of a jet engine? Just create a tunnel for the turbine to function in and in theory. Create more energy
My theory is that the additional drag caused by the fans at the front will offset any gains by powering the car from the fans rather than the alternator.
My prediction is a significant loss. Reason for is air is a fluid the same as water so its like putting a turbine on the front of a boat and its just going to add drag and not magically throw the mass of fluid around the vehicle and it will just hit straight after.... Little electric boat is much cheaper and would be far easier to engineer without the need for a heap of complexity, would likely have less losses and you could also add dye to the water and watch flow.... Pretty sure I mentioned something similar last time as to me it seems crazy to try test it full scale with the hope of getting good enough data to make a proper call one way or the other.... Have to be so much faster and easier to try 10x blade designs in a fish tank than trying to figure out whats going on while driving, safer too.
I have (had) a van with a bull bar, one would think this is a non aerodynamic accessory on every car but when laws in Spain forbid me to have it on the car and I removed it. Nothing else changed but since removal, my van is using 0.8 liter/100km more then before, same car, same tyres, same drive style, this bull bar saved me 100's of liters of fuel while making my van look nice(r) and protecting it against small scuffs.
You should look at air plane generators, Every aircraft has a generator which is basically a squirl cage fan and gen built right into the aircraft. A friend took one out of a Cessnas gen and installed it on his truck. It actually worked brilliantly. He use to use it to charge batteries for his motorhome.
It will work. It is also possible to power something straight into the wind using only wind power. If done right and the aerodynamics of the car aren't to affected by the generators in front of it, it should be possible to increase fuel efficiency.
I seem to see a bit of wobble on the mount as well as the car itself, so I'm thinking the wind turbine is creating a sort of vibration that also creates more wind buffering for the car, but I am no engineer and don't know all the equations
this is what I thought of... make a cowling for 2 smaller props and mount it on the top of ur car. next u need to design and build a venturi effect tube to mount them both in. it needs to be adjustable and maybe the prop pitch also. the air pressure drops a little while coming over the windshield, but air flow increases. this design also would make your device better acceptable to the NHTSA. HAPPY MOTORING!
I'm a pretty good guesstimator. With that being said, I feel like the wind turbines will disturb the airflow and prebuffet it before it hits the car helping your wind resistance a bit while collecting the wind energy so I feel like you'll save 20-25% on your gas mileage.
You made something similar to the APU (auxillary power unit) on big airplanes. Normally the APU is stored inside the plane, but when a large airplane loses its electric power during flight, they can deploy the APU and it generates electricity from the airflow. The fact that airplanes use the APU only in an emergency proves that it isn't an efficient way to provide power. The APU increases drag on the plane and slows it down.
thinking about it i think you are right. its similar to how the mythbusters proved following an 18 wheeler increases gas milage. the air hitting the car has a smaller speed differential because you've already removed some in the turbine. so instead of removing energy with the car body you are doing it with a turbine in front.
This was done about 55 years ago in NASCAR. Just about the most famous chief mechanic was Smokey Yunick. He mounted an alternator to the front of the radiator with a propellor on it. This was all behind the grille. Since the cars go between 120 and 200mph (200-300km/h) there was plenty of wind to spin the alternator. Then, he removed the alternator from the engine. Since the whole thing wasn't in front of the car, it had no effect on the aerodynamics of the body. It provided enough power to charge the battery and run the ignition system and gauges. His efforts were not applauded. As soon as the tech inspectors saw it, they immediately created a rule that banned it.
The whole idea of unhooking the battery while the car is running is a good way to test if your alternator is working I've done it a few times if you unplug the battery and the car suddenly stops the alternator isn't working but if the car continues running the alternator is fine
I agree the hypothesis is sound. I still think a bullet nose would bring a bigger saving. (Ups sorry, that comment is in the troll category). Rule of thumb says the average car has 20% of its drag from the grille and grille hood transition. That translates to 10-15% fuel savings eliminating that entirely. Still a worthwhile project. Also, by having props leaving fast turbulent air in front of the unmodified car, there is a chance that might be an aerodynamic drag reduction from that alone, avoiding the risk of larger vortex bubbles at the grille/hood and windshield/roof transitions.
Not really sure what you’re asking at 15:34 If you’re asking just for the difference, it’s simple. Your slipstream (how much turbulent air) will increase if it is mounted atop your vehicle… where in front of your vehicle it will increase your slipstream by such a small amount it will show very little change. Along with that, it will cause a lot of drag if mounted atop the vehicle. You’ll get more downforce on your rear axle, and that could be helpful if your engine was putting out enough power to warrant that, and it’s a RWD vehicle, but we simply aren’t looking for engine output/ performance, but instead looking for fuel mileage improvement. Along with that, if you need more downforce on your axle, you’d be better off moving it to the rear of the vehicle and making it cause as little drag with the most wind displacement and that would look like a spoiler… in fact it’d be a spoiler. So no need to do that.
The reason the propeller on the roof doesn't work where as the propeller on the front appears to work maybe, is that the air you need to push the turbine through you have to displaces with the vehicle anyway so it's kind of wasted energy recapture in that sense. In saying that you are introducing turbulence across the vehicle which may increase drag to the point that it stops making it worth it. Really interesting project! My gut reaction was to dismiss it immediately but what you're saying does make sense. More testing required!
Adding a 3rd support leg above coming from the hood might permit more stability and raising the fan. On hot days, this fan may reduce efficiency of the radiators at the front of the car.
To add additional regenerative charging for vehicles with electric motors I have been thinking it may be beneficial to add wind tubes with turbines in them that vehicle that would utilized generally during coasting or braking. what do you think of my idea?
If you mount your turbine on the roof, it will generate more power due to high upwind from the front and the wind speed passed the turbin is much faster than the speed of the car. If you put the turbine in front of the car and the turbine is too close with the bumper. That is the stagnation point where the speed is at slowest point.
Check the turbine in the rear of the car in the low pressure backwash that is less turbulent and more streamlined also using the vacuum that the whole car creates running through the air Also a ducted fan or impeller might be more efficient as it could utilize vacuum
I have no engineering class to speak off but what I know from electric car tests is that the wind-resistance and surface area a car has is a vital part for mileage a car can archieve. Designers of cars spend hours at perfecting the windflow over a car to minimize the resistance it has when driving. I would assume that placing windturbines infront of the car will create wind-pockets infront of the car's hood and bumper and will make many random swirls which might have the same effect like "turbulences" you can experience during a plane-flight. But less intense cause you not drive over 500-600 Mph and the effects quadruple with double of speed (If I not mess something up here). Those Turbulences might make the whole airflow concept of the car obsolete cause more air-friction will happen if those pockets "bump" into the car over and over again. I would assume the fuel efficency might suffer medium up to greatly from it. Now, cause my country uses a different kind of fuel-consumption scale...... It will decrease? - 10 to - 30 Percent? Going from like 20 miles per gallon down to 18 or even 15 miles per gallon?
Purdue ME/EE here. You failed to account for the extra work the engine has to do to sustain pushing against the turbine generator and the reaction force/work of the air flowing to turn the turbine . Where is your fuel consumption data? First Energy rule---"No such thing as a free Lunch"... The engine has added work to drive/operate the turbine system so yes the alternator has less load but the engine probably has more... again where is the fuel consumption data?
The point was always that the front of the car is completely blocking air flow at the front of the car. So that force is pushing the car to the rear with or without the turbine. If you add the turbine BEFORE the wind gets stopped dead, then you gather that winds energy right before it pushes the car back anyway.. yes there is some resistance created still by the turbine, but very little when compared to hitting the grill of the car, going through the radiator, hitting the engine and firewall, then getting forced out the underneath of the car, or out the wheel wells.
I had a battery fail in my car one time as i drove it. I realised that the engine would stall if I used the foot brakes, I attributed it to the current draw from the brake lights being too much and a battery was needed to even out the current demand like a capacitor. I limped my car home using the hand brake instead. If I recall correctly, the headlights (maybe full beam) would stall the car too. I replaced the battery and it ran like usual, even with two sub woofers in the trunk 😁
I showed this to a vehicle engineer friend of mine, and he said this is a field that had been heavily researched and abandoned due to their being no way around the net loss. Might want to look into the academic research.
Another idea I am working on is bladeless semi solid state turbine to attach to my car. Instead of a turbine I have a spring with a steel ball or weight on top. Almost any movement including wind makes it wobble and that is within a coil with magnet you know the deal. Seems hopeful
The Difference between front and top mounting is the incoming air speed your car experiences. You don't only need incoming air for the turbine you also need the air behind the turbine to flow away. According to Betz law the air behind an optimal turbine will be going roughly 1/3 the speed of the incoming air. So effectively if you cover your whole car you will get the same drag as if you were going 1/3 the speed and since drag scales quadratic with speed it's a lot less. The front mounted turbine might be less efficient though because the exhaust air can not freely flow away. So the efficiency of the whole design depends on how much the turbine increases drag and how efficient it is.
This is awesome and great to see thanks. I agree if it doesn't go beyond the size of the face of the vehicle it should help re-direct or break the air friction, making it more efficient. I thought a couple of things like maybe use a carpet blower fan or a squirrel cage of some sort like a waterwheel aspect. It might be better and for sure safer. and if you use a alternator as the generator in the floor blower. it should be get some rpm. Another thought was to use a boat propeller on the hitch and grab it that way. I don't have your means though. Anyway keep having fun it is fun to watch you guys
There's two levels going on here for the efficiency. The drag from the windmill on the frame take more power (Force * velocity = power) than the blade can generate (only ~30-40% efficient * alternator efficiency * drive belt efficiency). So that's strike one. Strike two is harder to prove, but messing up the air flow going to the car probably doesn't help air drag on the car. It gets complicated since you actually accelerate the air forwards before it gets to the car with the windmill. So it's better to look at it as a whole system, windmill + car, in which it probably has a worse drag coefficient.
Theoretically, you are transferring the workload of the car alternator to the "turbines" in front of it. Whether you like it or not, they will create a counterforce to the car, an aerodynamic drag that is inefficient and will lead to increased fuel consumption, which contradicts your goal of fuel savings. However, I like the project! 😺
if your wind turbine is more efficient than the alternator you should see a small fuel economy , i would guess that making the car more aerodynamic and increasing the yield of the car alternator would give you a significantely better fuel saving , in a way you are putting the alternator further away from the energy source inducing more loss in the system (gearbox , transmission , tires , aerodynamic ... ) . it is fun to try for real , thanks for the videos
I never thought of putting a turbine generator in front of the vehicle and on the pickup I believe induced drag would be difficult to detect or completely negligible. Even with the improved aerodynamics of the car I still think it would take some very careful work to identify the extra drag. I think damage to the front grill would create more drag than having that little turbine out in front. If you put the car with turbine(s) in a wind tunnel I think you would find turbulence over the hood and even on the road you might detect movement of the stationary windshield wipers. Do I think it’s causing drag? Yes Do I think it’s causing more drag than can be recovered? No Just found your channel and I’m enjoying watching, mostly to see you support the curiosity of your children. Keep up the great work!
As an Engineering student in the late 80s, I had proposed this kind of technology. It was a bit different in terms of having loads of smaller piezo generators with tiny turbines in the front grill connected to the secondary battery which in turn charges the battery. I am a Electronics Engineer and my Mechanical Engineering friends laughed me off. I thank you for making my idea work however a bit differently. I hope someone will try and get it right.
Just goes to show there are no new ideas. I'm a bit younger than you, and have thought about piezoelectric generators but instead of the grill vents, you'd have flapping turbines.
15:43 - The turbine on the top of the car increases the surface area of the car into the wind. The turbine in front hits the wind then that same air hits the rest of the car.
A turbine placed on the top of the vehicle has a clear airflow path behind it, while one places in front the vehicle had hindered airflow behind it. the fact that the is behind it, is like a building placed behind a windmill , it will never produce the same amount of energy as one placed in an open field.
This is an interesting question, because power or drag of the turbine and the car cannot be isolated. In subsonic flow, the pressure downstream has feedback on the pressure upstream, meaning that the free stream velocity at the fan is smaller than the car’s speed, and hopefully the fan is reducing stagnation pressure in front of the car. Another important factor is the boundary layer on the skin of the car. Flow around the body would be more laminar without the fan, positioning the car in the wake would dramatically increase the friction and boundary layer thickness, due to the turbulent nature of the wake. I’m not sure if the efficiency can be increased, because there are too many factors in this scenario- the efficiency of engine, alternator, turbine, generator, converter, fan-to-bumper separation, and the speed because the dominant form of drag varies with speed. I would suggest testing it with a simpler system so the variables can be controlled, or run some CFD cases with varying fan placement and speed to check the drag components on the car and the autorotating turbine. This is fun, wish you luck! MS Aerospace Engineering by the way
Put the two fans in the front connected to the frame but in front of the wheel that way the air going to the sides can be vented into a duct with the turbines inside. Kinda wind tunnel the air into the turbines.
The biggest issue you'll face is the Betz limit of a wind turbine rotor. Which is essentially that under ideal conditions a rotor can only be 59% efficient. After that energy is transferred to the motor and converted to electricity, you're looking at 40% if you're lucky. This puts it on par, or a little bit worse than the efficiency stated for the alternator. So, best case scenario with the most optimized rotor, pitch and load control algorithm, you might reach the same efficiency as the standard alternator. While accelerating or coasting, the engine is providing the power to move through the air. Ideally, most of that air will be redirected by the car and be minimally disturbed. Adding a turbine which is propelled by the car will only increase the drag of the vehicle, and subsequently use more power. If you want any help with blade design, I'm currently in school for Mechanical Engineering and am currently on a team for the Collegiate Wind Competition designing a similar scale wind turbine. Although, we only expect to produce around 50 watts. For energy generation blades with a higher tip speed ratio are better, which means they will spin faster. The TSR relates the speed of the tip of the blade to the bulk air velocity. A value of 6-10 is typical for energy generation, whereas a value of 2-5 is more for physical power. Since the bulk air speed is identical in each scenario, the lower TSR will produce more torque but less speed, and the high TSR will produce less torque but more speed. Usually a high TSR will result in a low solidity rotor, which is a measure of blade area to total rotor area. Think old farm windmills with lots of blades (high solidity) and modern turbines with long skinny blades (low solidity). Great testing and excited to see more!
I think a turbine would be effective in place of something like a spoiler or vertex generator - which garner some additional fluid friction for a greater saving in drag that comes from creating turbulent flow where the 'stream' of air leaves the vehicle. in this case, the goal is to create turbulent flow in itself, and while a turbine might not be as effective at this as something like a vortex generator, I think the recovered energy would be a net positive. Most probably best with multiple smaller props and higher rpm to minimise drag and maximise proper turbulent flow.
The battery isn't required for the car to run, however it acts as a huge capacitor protecting the electronics in your car from power spikes, it's not a good idea to disconnect the battery on a running engine.
I like to say my simple definition of a Gas Turbine Engine is: *_"An enclosed windmill that generates its own wind."_* YOU have created *_"A non-enclosed windmill that generates its own wind."_* 😊
My prediction is that you will have a slight net loss (~5%), for 2 main reasons: 1) You are affecting the aerodynamics of the car, since you are disturbing the air further in front of the car, 2) mechanical and electrical losses. Very cool experiment though!
Based on estimated losses or the generators and other factors, like wind direction, wind speed, needed generator speed, the space between the turbines and the car where the wind can go after and other such variables, I would expect you should get somewhere between 4% - 6% economy on fuel. Basically needed less for the same speed as before installing the turbines.
If you form your wind blades like a humpback whales fin in a ribbed format, your wind blades can become 30% more efficient. It all comes down to cavatation on the back side of the blades.
It's the way the question has been posed that's confusing! The effect is simple: Preferential Drag. When placing two bodies in tandem results in lower drag for the entire system. Pros simplify spinning blades into "discs", but with odd drag properties. The body in front of your truck takes energy to run, but harvests it in a very efficient way that is less than its drag thanks to the design of the airfoil and even its own lift! A side effect is the wake it leaves behind has lower energy air at lower pressures, so the body leeward of it encounters even lower drag, like you showed in a previous edition! Adding any streamlined shape in front of your car would likely reduce total drag, especially if that shape had a large wake. The turbine is just REALLY good at it; so good that it can tap out even more energy than it saves from the system in drag!
As another aside, energy can even be said to come straight from the air when utilizing pressure differences, such as in airfoils. Temperature on suction sides will have decreased, as will energy. Whenever propellers get mixed up in anything remotely orbiting "perpetual motion" like Veritasium's fan car, the energy (solar) extracted from the atmosphere is always missed.
RE: Putting the wind turbine in front of the car, I have a quick thought experiment for you to consider: Imagine your wind turbine was a propeller on an electric motor, it would push air over the car faster than if there was no propeller, yes? The wind turbine is literally the inverse: the wind turbine is slowing the air passing the car down more than the car would otherwise, yes? If you can agree that the air going over the car is slowed by adding the turbine (as otherwise we would have to imagine it is not sped up by the propeller in the inverse situation), we have net increased drag on the overall system, correct? It is not 'free' energy turning the turbine. Thus I expect the fuel efficiency loss is at minimum equivalent to the efficiency loss of the generator, plus the drag imposed by the structure of the wind turbine.
It will work. I've wanted to test this but incorporated more into the air streams! Look at the Mexican company that did this a number of years ago and then combine it with being able to make changes in aero dynamics to improve further.
Your kids are so lucky to have a dad like you! That must be so much fun!
I think he is lucky to have those kids as well. My kids are not interested in these kind of experiments at all. Anyways it is good to do fun things together as a family
ME engineer here. Great work, indeed you are not increasing drag due to frontal area but you increase it due to a higher coefficient of drag, which is a linear increment, and because you are placing the turbine at the area where air is usually stagnated it really should not make much worse airdynamics. Your work is truly great, if you are able to recup 15% of lost energy that is going from 20 mpg to 23 mpg out of thin air. You may want to add deltas at the wing tips. You may be losing a portion of torque due to induced drag due to the AR of the blades. Great work, keep encouraging your children, it's awesome
But like, don't they have alternators for this?
@@miepmaster25yes but the alternator costs fuel to run. The more electrical power you demand from it the greater the load it places on the engine.
My gut is that you're right and that further disrupting already turbulent air will show a net gain. But then again fluid dynamics is complicated and changing the flow of that air may have other, more complex effects on efficiency that are hard to predict. Either way I know that my maths isn't good enough to work it out, so I look forward to seeing the results!
Modern vehicle design tries to produce as little turbulence as possible, since turbulence results in higher drag, so my main thinking is that the fan, which creates turbulent air, is going to "undo" the aerodynamic design of the front end of the vehicle to some extent. This will be less impactful at slower speed, but at highway speeds aero drag becomes a much bigger component of efficiency, so I think it will come down to just how effectively the power generation can make up for it. The power required by the alternator is a small enough margin, that it could result in some gains at slower speeds, and some losses at higher speeds.
My feeling is that the power recovered will be inversely proportional to the drag coefficient of the vehicle. The higher the drag, the less power recovered. But that the additional fuel consumption will be directly proportional to the power recovered give or take efficiency. (would definitely prefer a brushless generator with bridge rectifiers) which may not may not offset the alternator load.
@@FlesHBoX⚠️ God has said in the Quran:
🔵 { O mankind, worship your Lord, who created you and those before you, that you may become righteous - ( 2:21 )
🔴 [He] who made for you the earth a bed [spread out] and the sky a ceiling and sent down from the sky, rain and brought forth thereby fruits as provision for you. So do not attribute to Allah equals while you know [that there is nothing similar to Him]. ( 2:22 )
🔵 And if you are in doubt about what We have sent down upon Our Servant [Muhammad], then produce a surah the like thereof and call upon your witnesses other than Allah, if you should be truthful. ( 2:23 )
🔴 But if you do not - and you will never be able to - then fear the Fire, whose fuel is men and stones, prepared for the disbelievers.( 2:24 )
🔵 And give good tidings to those who believe and do righteous deeds that they will have gardens [in Paradise] beneath which rivers flow. Whenever they are provided with a provision of fruit therefrom, they will say, "This is what we were provided with before." And it is given to them in likeness. And they will have therein purified spouses, and they will abide therein eternally. ( 2:25 )
⚠️ Quran
@@FlesHBoXyeah. Drag on a vehicle is usually more laminar at the front and becomes progressively more turbulent as you get to the back. Which is part of why I think placing a turbine (probably a VAWT turned so it's axis of rotation is parallel to that of the rear wheels) where you'd place a spoiler would be best
I'm not an expert in aerodynamics, but AFAIK essentially the airflow generally "finds its way of least resistance" in order to "dodge out of way of the displacing car". Therefore, trying to "steal" the power from the way of that flowing air can only and merely increase its resistance (or worse yet disturb that path even more, making even more resistive path), equalling into increased drag on the car (as car needs to work harder to displace the air through more resistive/convoluted path).
A more sensible idea might be to alter the pattern of airflow into more efficient in first place, using passive means (spoilers).
On the other hand, wind turbines might have some use, if you could leave the airflow by the movement of the vehicle (mostly) untouched and instead utilize the natural wind. IIRC there do exist some kind of "turbine sailboats" working that way. For such setup, the best place might be on a tall enough wind tower on the roof.
It could theoretically be simple and less or more usable if the wind turbine was the only power source, like in those experimental turbine sailboats. But due to its low efficiency, it might be impossible to sensibly combine it with any other power source, as it will also cause kinda threefold added drag against the power put on the motion by the other source than it provides, and it might be technically difficult to make it "ignore" the driving-induced airflow, which is usually the larger portion of the overall in case of road vehicle.
@8:00 “Hope is not a strategy” - L O L. so true
I don't even care about the tech, as a recent dad seeing you doing this with your kids brings a tear of joy to me eyes. I can only hope my kids grow up as excited to learn as yours. Congratz on your beautiful family @quint
I love to see this man just exploding from the amount of pride his son gives him
I spent 15 years with the same haircut your son has... but I spent 0 years with a dad as rad as you. Keep doin what you're doin.
I LOVE content like this. So many people assume they have all the answers figured out, but I love it when people actually put it to the test, and seeing your son get all into it all with you really makes me happy.
I just want to say you're an awesome dad. I wish I had a father like you.
I love this channel and seeing your children get involved and learn has been the icing on the cake and every father's dream. That said, I suddenly see how your son's grown up, so it suggest you're not releasing nearly enough videos. Please remedy the issue. All the best
I love how your son has taken off with his coding and electrical knowledge. I can see him becoming an engineer like his dad.
This is such an exciting project and I'm so jealous that your kids are involved and surpassing you. Just cannot wait for your next video
Instead of a electronic pitch control for the blades, maybe what you need is a Constant Speed Propeller system, that is used in small aircrafts. The difference will be just that your propellers are set to react to the wind, not try to use it to create thrust.
The drive uses counter-weights to keep the propellers at a constant speed.
I love going down rabbit holes other people have never tried, you learn a lot even if it doesn't work out. I pulled the 3.1L V-6 out of my Cavalier while leaving the transaxle in, people said it couldn't be done. I even did it without an engine lift! Going back in, I put the clutch/ pressure plate on the input shaft of the transaxle before lowering the engine in. Once the engine was in and bellhousing bolts were installed/ torqued, I attached the pressure plate to the flywheel one bolt at a time through the starter opening as I rotated the engine 60° at a time. Then one more revolution to torque them. The best part was no clutch alignment tool was required, the actual input shaft did the job.
Anyway, Newton's 1st law says you're not going to see any gains. In reality, you might see a small gain if your new charging system has much better efficiency... or you might see some loss. The torque required to turn the blades is countered by more "push" from the car which required more HP at the wheels. If your charging system efficiencies are the same, you'll see a decrease in MPG. Instead of the HP going directly to the alternator, your wind turbine will make the HP go through the powertrain which has inefficiencies in itself. While you're pushing the same air out of the way, the car now has to overcome the force (torque) required to rotate the turbine... see what Sir Isaac Newton says about a body at rest with a force acting on it. The force on the "body" (the wind turbine/ generator is at rest relative to the car) from the torque of the generator is opposed by an equal but opposite force from the car. You may see further losses due to disrupting the laminar air flow over the car.
Thermodynamics/ entropy wins again... sorry. But I'm jealous that I didn't get to go down that rabbit hole with you. You're very fortunate to have those tools/ equipment and your children are very lucky to have you as a dad.
I'm glad to see you continuing to make videos😊. I hope you joy this idea for a relativly easy diy cheapest plugin hybrid.
1) Disconnect the car's electrical system from the alternator and battery.
2) Then run the car's electrical needs from 4 deep cycle batteries. And
3) use a battery charger to recharge them at home or on the road. That's the basic idea.
4) optionally: If one wants long range, then add battery capacity or plan to switch the alternator back when needed.
Next level cheapest pluhin hybrid to replace the alternator with a 1kw motor. And use that to provide up to 1kw of mechanical power via the alternator belt. At this stage one probably wants to switch to Lithium based batteries for its energy density and longevity over lead acid.
On difference between fan on top versus in front. By far this isn't a complete description of the difference but I hope it helps.
1st in front, the fan generator under load creates a high pressure pocket in front of the blades and low pressure pocket behind it. This pushes some of the air around the car creating an aerodynamic slip stream as the car drives in the wake behind the fan. obviously the benifits are canceled in large part by the electrical load on the turbine and the turbine being pushed by the car. If the car were not pushing the turbine, riding in the wake would be similar to practice of race cars traveling in the wake of a cars infront if it. Once when I had virtually no money for fuel and needed to go several hundred miles, I drove uncomfotably close behind tractor trailers using their wake and using the slip stream effect to improve my fuel econony. Maybe the tresulting turbulence down wind from the blades effects the car's aerodynamics. But the turbine's exhaust is slower moving and might not have as much drag on the car.
Secondly, the air passing the turbin placed on top is slightly boosted by air speeding up as it goes over the top car. It might be easyer to generate power in faster wind, but there's no chance it could reduce drag on the car as there might be if placed in front.
Suggestion🗣❗️; I think you should explore different forms of wind turbines. One wind turbine I have in mind is the "Flying Clothesline" design because it can cover the entire frontal area of the car. Airloom modernized the design so take a look at theirs as well.
Best of luck to your scientific journey🎉❤
“Hope isn’t a strategy” thats a great quote
To make it more streamlined, try enclosing the fan or multiple fans in a tube, simular to a jet fuselage & making the tube or multiple tubes along the car body
The car already uses the air in front of the car to cool the motor. So by that same principle, I feel a turbine in front should work (unless somehow it blocks the cooling of the engine and reduces its efficiency). Great video !
it is so weird seeing you drive around on roads that i know from when i lived in the area (still do, just a little farther away), and as a freshly graduated mechanical engineer, seeing these projects is just so much fun.
Here's that answer you requested:
First, my background -- I'm 75 and have built wind turbines for about 55 years.
Okay, the answer:
A wind-tunnel simulation would clearly show the area in front of your vehicle COMPRESSES the airflow.
A better turbine application (IMHO) would be to use a VAWT mounted horizontally either lower (if room allows) or higher at a point tangent to the radius of your car's hood.
In either location. doing this places your wings directly WITHIN the airflow.
Sidenote: I build small compressed-air operated engines as well as (mostly) VAWT wind turbines and all my windmills compress air whenever the wind blows in North Texas (24/7).
If I decide to build the contraption, I'm describing here, I'll post a "build" video on my own TH-cam chanel.
I'm not a mechanical engineer, but from my electrical engineer perspective I can see two things: first, supposing there's no wind, the total power available is going to be equal to the force punching the turbine forwards times the distance it displaces per second, and the force is provided by the car. On the other hand, your argument says that wind speed will decrease as it passes through the turbine. Assuming 100% efficiency for the turbine, the air is going to be at rest after the turbine passes. So assuming 100% efficiency for the whole system there would be no difference with or without the turbine, right?, but staring from Betz's limit we can be pretty sure that's not going to happen. Greetings from Colombia. Your channel is great!
On a different note
Man you are making some great memories for your kids and you together
Would it not be a better use of the energy captured to have a battery bank and a small electric motor providing power to one or more wheels to drive the vehicle without the full use of the engine, basically a hybrid but using wind power to charge the the system.
I think the project is very interesting and I would like to see how it turns out. I agree with the comments that there are many challenges to overcome, but I think it is possible to make it work. I would focus on the following aspects:
* The efficiency of the turbine: The turbine should be able to generate as much power as possible with minimal drag.
* The reliability of the system: The system should be able to operate reliably in a variety of conditions, including high winds and rain.
* The cost of the system: The cost of the system should be low enough to make it commercially viable.
I think that if these challenges can be overcome, then wind power on vehicles could be a viable alternative to traditional engines.
This also can be used in a small unit in the front of an electric EV auto
This will run a charging port to keep the EV so you can drive farther
Being an engineer my self has talked to a few EV retailers but all said it will not work and understand bearable to look at I told them all this can be put under the front compartment that is used for almost nothing
I love this this is a fabulous idea
Nice concept, here is two cents. The first issue addressed in aerodynamics is Frontal Area, a top mount will increase this area. While mounting props in front doesn't increase the area, it does make the prop less efficient due to back pressure, created by the car's nose. Beware of an uneven loads, due to such uneven pressures. Consider using a scroll or helix to drive the generator. Aligned in the vertical axis, has the potential of 'splitting the air', in a similar way water repellents are used in modern underwater bullets. Harvesting air flow from the rear deck lid (spoiler) has a potential to increase stability, and use the partial pressure created at the rear. Not an electrician, but disconnecting the battery can damage the alternator charging circuit. Which questions using super capacitors, due to low resistance (great for delivering starting amps). Good to see you recognize electricity generation is only 50% efficient, something the greeny idealist don't want known.
I know you don't post that often, but it's always a joy when you do :) (...and tell your kids they are very lucky having a geek-dad!)
You are a modern day mad scientist my friend.
The turbine in front is where the air will be displaced anyway meaning it can’t be worse. If you put it on top of the car it will have a similar effect to what happens on a sail boat. It will catch air that is not doing work(as he mentioned) therefore increasing the amount of energy required by the car to keep moving.
I look forward to the next video on this topic.
Love it! Maybe something like the Archimedes spiral/screw turbine blade might better capture the wind given the variability due to the cars aerodynamics...
Just a small word of concern... That tube mounting the turbine to the vehicle seems to be flexing dangerously close to the road when you hit bumps. I suggest you opt for a more rigid attachment. Watching the video I couldn't help but think "god if that tube hits something it might impale the cabin".
I want to thank TH-cam SSSOOOOOO MUUUCH for not notifying me about this upload. Great video.
Let me give my two cents on the issue of the turbine on the roof vs the turbine on in front.
At the end of the day, what matters is the drag on the car; that is what the motor is resisting. I think your van very clearly increases the drag of the car. It is just very much less tear drop aerodynamic with a spinning turbine in front. When it comes to aerodynamics, you want laminar flow, not turbulent flow. My worry is that not only does the turbine itself cause drag, but that the turbine also causes there to be less laminar flow over the body of the car. As someone who is a cyclist and knows the pain of being in the wind versus the relief of being in aerodynamic, my guess is that you end up costing more in drag from a loss of aerodynamics than you gain from the generator. The turbine on top is probably worse, for the reasons you give. The cross sectional area is just much larger. However, you do save the aerodynamic flow around the body of the car, but my guess is that the extra cross sectional area dominates there. Overall, turbine in the front is probably better than turbine on top, but no turbine is probably better than turbine in the front.
Yep, the turbine itself just freewheeling would add drag and mass to the car. Adding the draw from the generator will increase increase drag even more. No matter what, that energy is coming from the motor, all that has been added to the system is more drag, more mass, and the inefficiency of the generator converting kinetic energy to electricity. It's all waste energy.
Even if the fan *somehow* made the system more aerodynamic, why attach the generator to it? The generator is just going to lose energy compared to the alternator taking the energy directly off the drive train.
So why not put the generators in the bed of a pick up truck towards the front? I remember an episode oh Mythbusters showing how the air swirls in your bed while the tail gate is up. Seems like that would be an ideal place for turbines without any extra drag on the vehicle. (obviously pickup only)
I'm super excited about this project! Best of luck.
Not sure if this has been commented but if the turbine is on top, you're creating more drag because you're creating more wind resistance because of the total capacity breaking through the wind, not just the height of the car, then an additional two or three feet above the car, thus creating more drag. For the front of the car, could you get better wind turbine response if your wind turbine was set up similar to that of a jet engine? Just create a tunnel for the turbine to function in and in theory. Create more energy
My theory is that the additional drag caused by the fans at the front will offset any gains by powering the car from the fans rather than the alternator.
If anyone didn't already know, the alternator doesn't just power everything while the engine is running, it also charges the battery.
This is your best content. genuinely good to see your rational.
My prediction is a significant loss. Reason for is air is a fluid the same as water so its like putting a turbine on the front of a boat and its just going to add drag and not magically throw the mass of fluid around the vehicle and it will just hit straight after.... Little electric boat is much cheaper and would be far easier to engineer without the need for a heap of complexity, would likely have less losses and you could also add dye to the water and watch flow.... Pretty sure I mentioned something similar last time as to me it seems crazy to try test it full scale with the hope of getting good enough data to make a proper call one way or the other.... Have to be so much faster and easier to try 10x blade designs in a fish tank than trying to figure out whats going on while driving, safer too.
It is so cool you work with your son on these projects.
Hahahah, "Hope is not strategy". Sir, i love this saying. Thank you.
I have (had) a van with a bull bar, one would think this is a non aerodynamic accessory on every car but when laws in Spain forbid me to have it on the car and I removed it.
Nothing else changed but since removal, my van is using 0.8 liter/100km more then before, same car, same tyres, same drive style, this bull bar saved me 100's of liters of fuel while making my van look nice(r) and protecting it against small scuffs.
You should look at air plane generators, Every aircraft has a generator which is basically a squirl cage fan and gen built right into the aircraft. A friend took one out of a Cessnas gen and installed it on his truck. It actually worked brilliantly. He use to use it to charge batteries for his motorhome.
Severely underrated channel my friend
What an awesome dad you are.
It will work. It is also possible to power something straight into the wind using only wind power. If done right and the aerodynamics of the car aren't to affected by the generators in front of it, it should be possible to increase fuel efficiency.
I seem to see a bit of wobble on the mount as well as the car itself, so I'm thinking the wind turbine is creating a sort of vibration that also creates more wind buffering for the car, but I am no engineer and don't know all the equations
this is what I thought of... make a
cowling for 2 smaller props and mount it on the top of ur car. next u need to design and build a venturi effect tube to mount them both in. it needs to be adjustable and maybe the prop pitch also.
the air pressure drops a little while coming over the windshield, but air flow increases.
this design also would make your
device better acceptable to the NHTSA. HAPPY MOTORING!
I'm a pretty good guesstimator. With that being said, I feel like the wind turbines will disturb the airflow and prebuffet it before it hits the car helping your wind resistance a bit while collecting the wind energy so I feel like you'll save 20-25% on your gas mileage.
You made something similar to the APU (auxillary power unit) on big airplanes. Normally the APU is stored inside the plane, but when a large airplane loses its electric power during flight, they can deploy the APU and it generates electricity from the airflow.
The fact that airplanes use the APU only in an emergency proves that it isn't an efficient way to provide power. The APU increases drag on the plane and slows it down.
This video is so dense with cool info. Great content!
So glad you're still doing your thing 💪🏻💪🏻💪🏻
More rain gutter hydro- I'm sure you can make it viable
thinking about it i think you are right. its similar to how the mythbusters proved following an 18 wheeler increases gas milage. the air hitting the car has a smaller speed differential because you've already removed some in the turbine. so instead of removing energy with the car body you are doing it with a turbine in front.
This was done about 55 years ago in NASCAR. Just about the most famous chief mechanic was Smokey Yunick. He mounted an alternator to the front of the radiator with a propellor on it. This was all behind the grille. Since the cars go between 120 and 200mph (200-300km/h) there was plenty of wind to spin the alternator. Then, he removed the alternator from the engine. Since the whole thing wasn't in front of the car, it had no effect on the aerodynamics of the body. It provided enough power to charge the battery and run the ignition system and gauges.
His efforts were not applauded. As soon as the tech inspectors saw it, they immediately created a rule that banned it.
Thx, I've got his book with pictures of the original.
The whole idea of unhooking the battery while the car is running is a good way to test if your alternator is working I've done it a few times if you unplug the battery and the car suddenly stops the alternator isn't working but if the car continues running the alternator is fine
I agree the hypothesis is sound. I still think a bullet nose would bring a bigger saving. (Ups sorry, that comment is in the troll category). Rule of thumb says the average car has 20% of its drag from the grille and grille hood transition. That translates to 10-15% fuel savings eliminating that entirely. Still a worthwhile project. Also, by having props leaving fast turbulent air in front of the unmodified car, there is a chance that might be an aerodynamic drag reduction from that alone, avoiding the risk of larger vortex bubbles at the grille/hood and windshield/roof transitions.
“Hope is not a strategy”😂 wise words
Not really sure what you’re asking at 15:34
If you’re asking just for the difference, it’s simple.
Your slipstream (how much turbulent air) will increase if it is mounted atop your vehicle… where in front of your vehicle it will increase your slipstream by such a small amount it will show very little change.
Along with that, it will cause a lot of drag if mounted atop the vehicle. You’ll get more downforce on your rear axle, and that could be helpful if your engine was putting out enough power to warrant that, and it’s a RWD vehicle, but we simply aren’t looking for engine output/ performance, but instead looking for fuel mileage improvement.
Along with that, if you need more downforce on your axle, you’d be better off moving it to the rear of the vehicle and making it cause as little drag with the most wind displacement and that would look like a spoiler… in fact it’d be a spoiler. So no need to do that.
I never knew about the battery thing! 😮 That is amazing! Loved this video thank you so much 👏
The reason the propeller on the roof doesn't work where as the propeller on the front appears to work maybe, is that the air you need to push the turbine through you have to displaces with the vehicle anyway so it's kind of wasted energy recapture in that sense. In saying that you are introducing turbulence across the vehicle which may increase drag to the point that it stops making it worth it. Really interesting project! My gut reaction was to dismiss it immediately but what you're saying does make sense. More testing required!
Adding a 3rd support leg above coming from the hood might permit more stability and raising the fan. On hot days, this fan may reduce efficiency of the radiators at the front of the car.
To add additional regenerative charging for vehicles with electric motors I have been thinking it may be beneficial to add wind tubes with turbines in them that vehicle that would utilized generally during coasting or braking. what do you think of my idea?
If you mount your turbine on the roof, it will generate more power due to high upwind from the front and the wind speed passed the turbin is much faster than the speed of the car.
If you put the turbine in front of the car and the turbine is too close with the bumper. That is the stagnation point where the speed is at slowest point.
You should look into "The Fan Showdown". You may be able to improve the fan blades and get better efficiency.
Check the turbine in the rear of the car in the low pressure backwash that is less turbulent and more streamlined also using the vacuum that the whole car creates running through the air
Also a ducted fan or impeller might be more efficient as it could utilize vacuum
I have no engineering class to speak off but what I know from electric car tests is that the wind-resistance and surface area a car has is a vital part for mileage a car can archieve. Designers of cars spend hours at perfecting the windflow over a car to minimize the resistance it has when driving. I would assume that placing windturbines infront of the car will create wind-pockets infront of the car's hood and bumper and will make many random swirls which might have the same effect like "turbulences" you can experience during a plane-flight. But less intense cause you not drive over 500-600 Mph and the effects quadruple with double of speed (If I not mess something up here).
Those Turbulences might make the whole airflow concept of the car obsolete cause more air-friction will happen if those pockets "bump" into the car over and over again. I would assume the fuel efficency might suffer medium up to greatly from it. Now, cause my country uses a different kind of fuel-consumption scale...... It will decrease? - 10 to - 30 Percent? Going from like 20 miles per gallon down to 18 or even 15 miles per gallon?
Purdue ME/EE here. You failed to account for the extra work the engine has to do to sustain pushing against the turbine generator and the reaction force/work of the air flowing to turn the turbine . Where is your fuel consumption data? First Energy rule---"No such thing as a free Lunch"... The engine has added work to drive/operate the turbine system so yes the alternator has less load but the engine probably has more... again where is the fuel consumption data?
The point was always that the front of the car is completely blocking air flow at the front of the car. So that force is pushing the car to the rear with or without the turbine. If you add the turbine BEFORE the wind gets stopped dead, then you gather that winds energy right before it pushes the car back anyway.. yes there is some resistance created still by the turbine, but very little when compared to hitting the grill of the car, going through the radiator, hitting the engine and firewall, then getting forced out the underneath of the car, or out the wheel wells.
I had a battery fail in my car one time as i drove it. I realised that the engine would stall if I used the foot brakes, I attributed it to the current draw from the brake lights being too much and a battery was needed to even out the current demand like a capacitor. I limped my car home using the hand brake instead. If I recall correctly, the headlights (maybe full beam) would stall the car too.
I replaced the battery and it ran like usual, even with two sub woofers in the trunk 😁
I showed this to a vehicle engineer friend of mine, and he said this is a field that had been heavily researched and abandoned due to their being no way around the net loss. Might want to look into the academic research.
If he can point me to where it's published I'd love to see it.
Another idea I am working on is bladeless semi solid state turbine to attach to my car. Instead of a turbine I have a spring with a steel ball or weight on top. Almost any movement including wind makes it wobble and that is within a coil with magnet you know the deal. Seems hopeful
The Difference between front and top mounting is the incoming air speed your car experiences. You don't only need incoming air for the turbine you also need the air behind the turbine to flow away. According to Betz law the air behind an optimal turbine will be going roughly 1/3 the speed of the incoming air. So effectively if you cover your whole car you will get the same drag as if you were going 1/3 the speed and since drag scales quadratic with speed it's a lot less. The front mounted turbine might be less efficient though because the exhaust air can not freely flow away. So the efficiency of the whole design depends on how much the turbine increases drag and how efficient it is.
This is awesome and great to see thanks. I agree if it doesn't go beyond the size of the face of the vehicle it should help re-direct or break the air friction, making it more efficient. I thought a couple of things like maybe use a carpet blower fan or a squirrel cage of some sort like a waterwheel aspect. It might be better and for sure safer. and if you use a alternator as the generator in the floor blower. it should be get some rpm. Another thought was to use a boat propeller on the hitch and grab it that way. I don't have your means though. Anyway keep having fun it is fun to watch you guys
There's two levels going on here for the efficiency. The drag from the windmill on the frame take more power (Force * velocity = power) than the blade can generate (only ~30-40% efficient * alternator efficiency * drive belt efficiency). So that's strike one. Strike two is harder to prove, but messing up the air flow going to the car probably doesn't help air drag on the car. It gets complicated since you actually accelerate the air forwards before it gets to the car with the windmill. So it's better to look at it as a whole system, windmill + car, in which it probably has a worse drag coefficient.
Theoretically, you are transferring the workload of the car alternator to the "turbines" in front of it. Whether you like it or not, they will create a counterforce to the car, an aerodynamic drag that is inefficient and will lead to increased fuel consumption, which contradicts your goal of fuel savings. However, I like the project! 😺
if your wind turbine is more efficient than the alternator you should see a small fuel economy , i would guess that making the car more aerodynamic and increasing the yield of the car alternator would give you a significantely better fuel saving , in a way you are putting the alternator further away from the energy source inducing more loss in the system (gearbox , transmission , tires , aerodynamic ... ) . it is fun to try for real , thanks for the videos
I never thought of putting a turbine generator in front of the vehicle and on the pickup I believe induced drag would be difficult to detect or completely negligible. Even with the improved aerodynamics of the car I still think it would take some very careful work to identify the extra drag. I think damage to the front grill would create more drag than having that little turbine out in front.
If you put the car with turbine(s) in a wind tunnel I think you would find turbulence over the hood and even on the road you might detect movement of the stationary windshield wipers.
Do I think it’s causing drag? Yes
Do I think it’s causing more drag than can be recovered? No
Just found your channel and I’m enjoying watching, mostly to see you support the curiosity of your children. Keep up the great work!
As an Engineering student in the late 80s, I had proposed this kind of technology. It was a bit different in terms of having loads of smaller piezo generators with tiny turbines in the front grill connected to the secondary battery which in turn charges the battery.
I am a Electronics Engineer and my Mechanical Engineering friends laughed me off.
I thank you for making my idea work however a bit differently.
I hope someone will try and get it right.
Just goes to show there are no new ideas. I'm a bit younger than you, and have thought about piezoelectric generators but instead of the grill vents, you'd have flapping turbines.
15:43 - The turbine on the top of the car increases the surface area of the car into the wind. The turbine in front hits the wind then that same air hits the rest of the car.
Wind Power on a Car #7 We are looking forward
7:04 they're growing up so fast, but that had to have been a proud papa moment. Done a good job.
13:40 definitely proud papa moment
A turbine placed on the top of the vehicle has a clear airflow path behind it, while one places in front the vehicle had hindered airflow behind it. the fact that the is behind it, is like a building placed behind a windmill , it will never produce the same amount of energy as one placed in an open field.
Basically a R.A.M. system that planes utilize
Do you mean RAT?
@@QuintBUILDs Why 'Yes' it's nice to know that someone understands and is paying attention.
Touchè😏
@@QuintBUILDs While you are at it
✅Out PROTEAN wheels
This is an interesting question, because power or drag of the turbine and the car cannot be isolated. In subsonic flow, the pressure downstream has feedback on the pressure upstream, meaning that the free stream velocity at the fan is smaller than the car’s speed, and hopefully the fan is reducing stagnation pressure in front of the car. Another important factor is the boundary layer on the skin of the car. Flow around the body would be more laminar without the fan, positioning the car in the wake would dramatically increase the friction and boundary layer thickness, due to the turbulent nature of the wake. I’m not sure if the efficiency can be increased, because there are too many factors in this scenario- the efficiency of engine, alternator, turbine, generator, converter, fan-to-bumper separation, and the speed because the dominant form of drag varies with speed. I would suggest testing it with a simpler system so the variables can be controlled, or run some CFD cases with varying fan placement and speed to check the drag components on the car and the autorotating turbine.
This is fun, wish you luck! MS Aerospace Engineering by the way
Put the two fans in the front connected to the frame but in front of the wheel that way the air going to the sides can be vented into a duct with the turbines inside. Kinda wind tunnel the air into the turbines.
The biggest issue you'll face is the Betz limit of a wind turbine rotor. Which is essentially that under ideal conditions a rotor can only be 59% efficient. After that energy is transferred to the motor and converted to electricity, you're looking at 40% if you're lucky. This puts it on par, or a little bit worse than the efficiency stated for the alternator.
So, best case scenario with the most optimized rotor, pitch and load control algorithm, you might reach the same efficiency as the standard alternator.
While accelerating or coasting, the engine is providing the power to move through the air. Ideally, most of that air will be redirected by the car and be minimally disturbed. Adding a turbine which is propelled by the car will only increase the drag of the vehicle, and subsequently use more power.
If you want any help with blade design, I'm currently in school for Mechanical Engineering and am currently on a team for the Collegiate Wind Competition designing a similar scale wind turbine. Although, we only expect to produce around 50 watts. For energy generation blades with a higher tip speed ratio are better, which means they will spin faster. The TSR relates the speed of the tip of the blade to the bulk air velocity. A value of 6-10 is typical for energy generation, whereas a value of 2-5 is more for physical power. Since the bulk air speed is identical in each scenario, the lower TSR will produce more torque but less speed, and the high TSR will produce less torque but more speed. Usually a high TSR will result in a low solidity rotor, which is a measure of blade area to total rotor area. Think old farm windmills with lots of blades (high solidity) and modern turbines with long skinny blades (low solidity).
Great testing and excited to see more!
Great project. It will increase the mileage surely.
I think a turbine would be effective in place of something like a spoiler or vertex generator - which garner some additional fluid friction for a greater saving in drag that comes from creating turbulent flow where the 'stream' of air leaves the vehicle.
in this case, the goal is to create turbulent flow in itself, and while a turbine might not be as effective at this as something like a vortex generator, I think the recovered energy would be a net positive. Most probably best with multiple smaller props and higher rpm to minimise drag and maximise proper turbulent flow.
The battery isn't required for the car to run, however it acts as a huge capacitor protecting the electronics in your car from power spikes, it's not a good idea to disconnect the battery on a running engine.
I like to say my simple definition of a Gas Turbine Engine is:
*_"An enclosed windmill that generates its own wind."_*
YOU have created *_"A non-enclosed windmill that generates its own wind."_* 😊
My prediction is that you will have a slight net loss (~5%), for 2 main reasons: 1) You are affecting the aerodynamics of the car, since you are disturbing the air further in front of the car, 2) mechanical and electrical losses. Very cool experiment though!
Then why do jet aircraft have points on the front of the aircraft to break the air for the sound barrier and turbulence.
@@systemsrenegade9888 can you show an example? The only "points" I know of are pitot tubes that measure air speed/pressure.
Based on estimated losses or the generators and other factors, like wind direction, wind speed, needed generator speed, the space between the turbines and the car where the wind can go after and other such variables, I would expect you should get somewhere between 4% - 6% economy on fuel. Basically needed less for the same speed as before installing the turbines.
If you form your wind blades like a humpback whales fin in a ribbed format, your wind blades can become 30% more efficient. It all comes down to cavatation on the back side of the blades.
It's the way the question has been posed that's confusing! The effect is simple: Preferential Drag. When placing two bodies in tandem results in lower drag for the entire system. Pros simplify spinning blades into "discs", but with odd drag properties. The body in front of your truck takes energy to run, but harvests it in a very efficient way that is less than its drag thanks to the design of the airfoil and even its own lift! A side effect is the wake it leaves behind has lower energy air at lower pressures, so the body leeward of it encounters even lower drag, like you showed in a previous edition! Adding any streamlined shape in front of your car would likely reduce total drag, especially if that shape had a large wake. The turbine is just REALLY good at it; so good that it can tap out even more energy than it saves from the system in drag!
As another aside, energy can even be said to come straight from the air when utilizing pressure differences, such as in airfoils. Temperature on suction sides will have decreased, as will energy. Whenever propellers get mixed up in anything remotely orbiting "perpetual motion" like Veritasium's fan car, the energy (solar) extracted from the atmosphere is always missed.
RE: Putting the wind turbine in front of the car, I have a quick thought experiment for you to consider:
Imagine your wind turbine was a propeller on an electric motor, it would push air over the car faster than if there was no propeller, yes?
The wind turbine is literally the inverse: the wind turbine is slowing the air passing the car down more than the car would otherwise, yes?
If you can agree that the air going over the car is slowed by adding the turbine (as otherwise we would have to imagine it is not sped up by the propeller in the inverse situation), we have net increased drag on the overall system, correct? It is not 'free' energy turning the turbine.
Thus I expect the fuel efficiency loss is at minimum equivalent to the efficiency loss of the generator, plus the drag imposed by the structure of the wind turbine.
Those naysayers talking about a car won't run unless it's battery's there and working have never pushed started a car!
To hell with the second law of thermodynamics?
It should definitely work for someone who isn't driving when everyone else is, that is busy traffic and often 5mph to and from work on the highway.
It will work. I've wanted to test this but incorporated more into the air streams! Look at the Mexican company that did this a number of years ago and then combine it with being able to make changes in aero dynamics to improve further.