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- เผยแพร่เมื่อ 2 ต.ค. 2024
- For more videos on motorbike aerodynamics:
Motorbike wheelies: • Sports Aerodynamics #2...
MV Agusta - MotoGP - part 1: • Race Talk with MV Agus...
MV Agusta - MotoGP - part 2: • Race Talk with MV Agus...
Damon motorcycles - electric motorbikes: • How to Design Electric...
In this video, we’ll discuss the motorbike aerodynamics with together with Joseph Katz, author of the famous book “race car aerodynamics”, professor at the San Diego State University and passionate motorbike rider.
Before we move on to the interview, let’s summarize some basic aspects of motorbike aerodynamics and how they differ from cars:
First of all, the drag: the frontal area, which is the area when looking at an object from the front, is much smaller for a motorbike. But to get the total drag on an object, you need to multiply this frontal area by the drag coefficient, which is much, much larger for a motorbike, offsetting the benefit of the smaller frontal area: it is filled with exposed bits of geometry like the wheels, brakes, and so on, and the surface the air needs to follow is hardly a smooth one: it’s full of abrupt changes like the end of the wind shield causing the flow to detach. And then there’s the rider, a massive disturbance to the air. So, the drag coefficient of a motorbike is easily double or more than that of a modern-day car.
Second of all, the centre of pressure, which is the point where the total sum of the pressure is acting, is quite high above the ground. With respect to the contact point of the rear wheel on the ground, this tends to push the motorbike backwards, lowering contact pressure on the front wheel, which reduces steering control. As the aerodynamic drag force increases with the square of velocity, this can become problematic at high speeds. So, trying to get the center of pressure as low as possible is crucial for motorbikes. A low rider position is a good start. Another way to balance things is to create down force on the front wheel to counteract this back-flipping moment on the bike.
In the interview, we cover the following topics:
Effects of leaning on aerodynamics
Engine performance
AMA superbikes
Rider position
Rear tire wear
Active aerodynamics
Wind tunnel testing
Centre of pressure
Ducati wings
Lateral forces
Helmet vibration
Better engine performance via RAM air
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The AirShaper videos cover the basics of aerodynamics (aerodynamic drag, drag & lift coefficients, boundary layer theory, flow separation, reynolds number...), simulation aspects (computational fluid dynamics, CFD meshing, ...) and aerodynamic testing (wind tunnel testing, flow visualization, ...).
We then use those basics to explain the aerodynamics of (race) cars (aerodynamic efficiency of electric vehicles, aerodynamic drag, downforce, aero maps, formula one aerodynamics, ...), drones and airplanes (propellers, airfoils, electric aviation, eVTOLS, ...), motorcycles (wind buffeting, motogp aerodynamics, ...) and more!
For more information, visit www.airshaper.com
Interesting video! I understand the problem of the Ducati wings. But if the motogp tires have a really high coefficient of adhesion can the increase in normal force still payoff the force pushing outside?
That's correct: in theory, if the friction coefficient is higher than one, the effects should be positive indeed! But one slippery patch on the road and you'll quickly notice the negative effects :)
Kyle engineers a former mercedes f1 engineer actually addressed that concern on his channel, because the centre of gravity changes when cornering, the effects of the wing changing angle in corners is not negative at all
The solution for side force is to cant the wings with a few degrees of Ahedral, and the angle of attack to s point where the inside wing during a corner will stall out and not produce any side force, whilst the outside wing will be producing downforce into the Tyre near its most efficient point.
This is why motorcycle wings aren't just worried about the longitudinal plane, and have the Yaw/Z plane into account.
@@Bull_10RR Ducatis don't look to have much of an ahedral angle . On the Aprilia yes
that's insane. so even though a car is 5X the weight of motorcycle it only has 1.5X the aerodynamic drag. this explains why EV cars get 300 miles of range while EV bikes only get 100 miles of range. because cars have 5X battery but only 1.5X drag and therefore 3X range. this also explains why EV car gets almost the same economy in city and highway while a motorcycle gets 3X the range in city vs highway. so basically EV motorcycle is useless on the highway. i watched your videos to understand whether EV motorcycles make sense from standpoint of energy efficiency and the answer is yes only as long as you don't go on the highway. thank you for the great content.
Nice comparison!! Indeed, the ratio between Cd and weight/volume/battery capacity is challenging for motorbikes. The limits on weight increase are more stringent on motorbikes than on cars, when it comes to switching to batteries. But then again, perhaps the "desired range" is lower for bikes :)
@@AirShaper absolutely - bikes don't need as much range because they supplement rather than replace cars. the main advantage of EV bikes is probably rider comfort due to less heat.
Great video, would love to see more interviews with Mr Katz, really enjoyed his book.
We hope we can have more interviews with him as well - his experience is vast!!
Turd Ferguson Yeah I agree
Great video with two masters of this topic! 👏👏👏👏 Thanks for this valuable content, specially for those (i include myself) who are just starting to get involved in this amazing and passionate Aerodynamics world!
You're most wecome Eduardo! We also have videos where we interview MV Agusta on MotoGP aerodynamics, and also one with Damon motorcycles. Hope you like those as well!
Great video! I have been designing an electric commuter motorcycle trying to use aerodynamics and weight reduction to reduce total energy consumption. There are very few videos that discuss this so I am always looking for other people that actually talk about aerodynamics and motorcycles. One of my challenges is that I am planning a much smaller motorcycle than where the research of race bikes is so a full size super bike is already at a quite a bit of a disadvantage. My project actually incorporates comfortable ride and currently working on the most useful balance of weight and aerodynamics. Much like the products of the Craig Vetter Fuel Economy Challenge but engineered from the start rather than a modified scooter.
Hi Chris, that sounds very interesting! How far are you with the project: design, prototyping, ...? Is it a hobby project or are there plans for commercialisation? Feel free to get in touch via info@airshaper.com!
Lets talk about it in a bit... I'm doing the same thing... I'd be great to share notes. Check Norton Kneeler, you'll get some design cues from it. Also check the Britten v1000 I think it is called.
Harley Davidson leaves the chat 😂
Haha each to their own, when it comes to designing or choosing a motorcycle 🙂
great video find it very interesting, please can you give a bit more information on rider position and the affects on top speed as i race at the isle on man tt which is a lot of high speed and would be very helpful and i can't modify the bike a lot as the regulations are very tight. many thanks like the videos
Hi Trev, racing the Isle of Man, that's insane :)
In the meantime, we created some more videos on motorbike aerodynamics:
th-cam.com/video/BUkaejkHRn8/w-d-xo.html and th-cam.com/video/fGNdMaVft_w/w-d-xo.html
I hope they're useful!
Thanks for the video man👌🏽💡
You're very welcome Thor!
Dude you hit the nail on the head talking about ground effects, no wonder Joseph preferred to keep silent lol. Now with Ducati's shape shifter ,its all the more apparent.Great video .
Hi Jon, thanks a lot! Indeed the shape shifter alters the 'global' angle of attack of the bike. Maybe you'll like this article:
www.motorsportmagazine.com/articles/motorcycles/motogp/the-story-behind-ducatis-new-motogp-shapeshifter
Just found this channel today and i watching all the videos right now. This is some awesome content. And the sir you have with you on this video, what a guest. Just a few weeks ago i got his book. Its very good indeed.
I'm glad you discovered the book of Joseph! He's indeed extremely knowledgable. And glad you like pur videos!
eBikes?
i was trying to find some data about this and i came across one website that said that "Honda RS125 GP" has like 0.2 drag coefficient. do you think it's real? or could i possibly be misunderstanding the data? seems like that would be very low for motorcycle.
Hm, that sounds highly unrealistic, such a low drag coefficient for a motorbike...
@@AirShaper yeah it seems very low. I tried to look for the max speed and max power and dimensions for this bike and tried to calculate the drag coefficient based on those and i came to the conclusion that it might have around 0.3 drag coefficient because otherwise i think it would need more power to achieve that top speed.
@@AirShaper if my calculations are correct then it would probably be very nice to make similar bike but electric. 🤔
@@oplkfdhgk We've been working on various electric bikes. But it's only the very streamlined ones (for records, ...) that can go below a Cd of 0.30. Also, the position of the rider maters a lot, and most will not maintain an uncomfortable one like you see in MotoGP races. Just some thoughts!
@@AirShaper makes sense. 🙂
That's the reason winglets are banned in MotoGP