Worlds First 'Real' R/C Ground Effect Vehicle
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My defenition of a ground effect vehicle is when it can fly in the ground with a much higher efficiency than flying normally in the air
Even the old Russian ones could easily get up to 300 meters, well above groundeffect.
Yeah. That's the more interesting definition anyway. It should derive some actual advantage, in this case efficiency, from the ground effect.
@@grimfpv292 Did you miss about the efficiency part in the comment you reply to? Yes it could but it was not effective, so whats the point with your comment?
@@grimfpv292 yes but most of them were unstable above groundeffect, the only one who was really able to fly efficiently both in the groundeffect and out was the VVA-14 and he had a bigger aspect ratio that any other ekranoplan
That´s true for every aircraft
Perhaps people think being in ground effect is just flying low to the ground, but it's a very different set of flight characteristics when in ground effect. So as you said if it's designed to exploit ground effect as it's primary mode of operation then it's a ground effect vehicle. It would be like saying an off-road vehicle isn't an off-road vehicle because it can still drive on the road. Sure, but that's not what it's design goal was, or what it's best at.
I feel like this is the best comparison
My thoughts exactly. A vehicle is names because of what it's designed to do not necessarily what it can do. The Spruce Goose couldn't fly out of ground effect but no one calls it a ground effect vehicle because it wasn't designed to be one. It was a flying boat that was underpowered. Versus in this case a GEV that is overpowered.
Airplanes can utilize ground effect, but they can still fly high, GEVs cannot break free from ground effect. Just like a wrench can be used as a hammer to drive a nail, but a hammer can't be used as a wrench.
@@nogland8916 The Spruce Goose definitely could fly out of ground effect, but didn't because it wasn't even supposed to take off at all because it wasn't needed for the war effort anymore. It only took off by "accident" (there is debate about wether Hughes may have done it on purpose to prove it could fly) during a taxi test. It never did go fully out of ground effect but only because they didn't do it, NOT because it couldn't.
@@Eidolon1andOnly
"GEVs cannot break free from ground effect."
Why? Because you say so?
So are you saying that it should be aerodynamically impossible, or that you're not allowed to add power to make it possible?
My best result with free flight ground effect gliders has come from a design with a low wing and high tail, like the Lun/Caspian Sea Monster. I keep the CG pretty far aft, so the tail has to generate lift at all times. The lifting tail is the key.
For a given speed, the tail always generates the same amount of lift, because it is out of ground effect. The wing, however, generates more lift as it gets closer to the ground. If you launch the glider too close to the ground, the wing generates a surplus of lift, and climbs higher, reaching equilibrium against the tail’s lift. If you launch it too high, it dives toward the ground because the wing is not generating enough lift to balance the tail’s lift. But as the wing approaches the ground, it generates more lift, and finds equilibrium.
This is the positive feedback loop you are looking for. The key is a high-mounted lifting tail, out of ground effect, and a low wing in ground effect.
That's fascinating, thank you. This sounds like the key to better GEV flight characteristics to me.
Thanks GW
This makes sense. The ground effect is real, but it's pretty weak at R/C scale and the falloff is kinda gradual. Adding the external tail is the perfect solution to making a self-correcting system.
Then you can simply fine-tune the tail lift (elevator trim?) to find the most efficient ground effect height.
@@haphazard1342 exactly. You make coarse adjustments with the CG and incidence of the wing, and then fine tune it with elevator trim.
Elevator trim affects altitude and airspeed. Trim nose down, and you will either fly lower at the same speed, or faster at the same height.
I have heard that ground effect vehicles work better when they are heavy so they have to compress the air cushion more. either real engineering or mustard said that in their video.
so instead of reducing the thrust you increase the weight which might reduce the sensitivity to wind and widen the speed range at which the vehicle is stable. more mass might also reduce the twitchy behavior as the nose doesn't rise so quickly.
you know you're doing real RC experimentation when a kayak is part of the required kit.
Wow you won as well, congrats. I bet this is real and not a scam.
@@brei.z hey. I won, too. I never win anything
@@gbaker9295 I emailed a screenshot to rctestflght but he might get alot so not see it for awhile.
he clearly needs a full size gev to chase his rc one
@LazerLord10 : Just as well he did!... the helpful local paddler turned out to be a fizzer, just being nosey!
The Caspian sea monster was designed to haul extremely heavy loads. Increase the scale and weight, that should smooth out the rough spots and start getting consistent results.
Yes. The elasticity of the air doesn't scale down with the size of the vehicle. We can reasonably assume that there is an optimal scale for ground effect vehicles which is dependent on the physical properties of the fluid being operated in. So for earth atmosphere at sea level, there will be an optimal size of ground effect vehicle which is able to maximize benefit.
It also seems plausible that there is a Pareto curve of optimal speeds for a given vehicle size, where the dependent variable is the vehicle weight (payload).
Bingo. Mass dampens all external input.
I think this has been said on every single GEV video and he hasn't taken any notice. He always complains about it being too bouncy or taking off too early, which makes it pretty clear it needs more mass.
@@charlesturner897 Or more precision. Yes, more mass gives you more tolerance. But his quest is to find the exact sweet spot where it still works.
7:24 that's a Great Crested Grebe as far as I can see... They're amazing divers. They can do 20M underwater with no problems. It dove well off screen 😊
NICE
Agreed. Very common here in the UK. and expert divers, preferring to dive rather than fly to escape danger.
If you watch the one in the background, it looks like it dives and then instantly teleports to where the arrow is.
@@R9000 your right that's funny i didn't catch it the first time .
Lol teleportation
I have two proposals/theories/questions:
1: If the vehicle had a larger wing area and more mass to shove the air down with, that should increase the height and speed bracket at which GEV is sustainable, and there for also increase the ease of obtaining successful ground effect for extended periods of time.
2: I am unconvinced that the underside of the wing would play too much in the role of stability, but it would be interesting to test if funneling air to the tips of the wings some how would make the vehicle more stable. I could cad it out if you want because my description is not very good. I'm thinking of a multi axis sweep that has the effect of having air come out horizontal in the center of the vehicle, but a bit more perpendicular to the water near the wing tips.
Combining these two theories may create some interesting findings, or a spectacular failure and waste of time. :D
I'm not sure if funneling air to the tips of the wing is a good idea, since that will increase wingtip vortices. I don't think GEVs have much of a roll axis instability problem anyways, since the lower wing will always produce a lot more lift than the upper wing. There's only altitude/pitch instability.
don't know though not an aerodynamicist
Thats partially what I was thinking too, since this isnt a traditional aircraft, and thus doesnt need to be super light, more weight might help the slight breezes have less of an impact on it.
I think the Ekranoplane was an attempt to reduce shipping costs and times. The idea was air drag is significantly lower than water. If a wing appliance could be developed that would unload the hull enough to eliminate the water contact... you win.
However, the world has resigned itself to creating bigger and bigger slow moving ships to just solve the cost issue. :)
In most real world things throughput is much more important than latency. The Ekranoplane design is in that weird middle ground between “I need it tomorrow put it on a plane” and “I need 100,000 of them at some point”
So a hydrofoil?
@@OntarioTrafficMan not exactly, well pretty much, but without the hydrofoil in the water.
@@OntarioTrafficMan A hydrofoil still have contact with the water and the speed it is effective at is lower than what you get with a ground effect vehicle (GEV). With a hydro foil there's a point where it will start to cavitate and lose a lot of the lifting force, which is a very bad thing to experience at a relatively high speed. Crashing down into the drink is likely to result in some pretty spectacular acrobatics involving 360 flips end over end.
A GEV on the other hand forsakes the ground contact al together and going to fast will just result in it taking off like an airplane.
A hovercraft is more comparable, but this too has a much lower top speed than a GEV. If you press a hovercraft to far it will outrun the air cushion that keeps it from slumming with the rest of us that depend on buoyancy or wheels to keep us from dragging in the dirt or sinking in water. Thing is that the faster the GEV flies the more air is pressed down under it building up the cushion that keeps it aloft. So there's no risk of outrunning it before you start nibbling at the speed of sound. But if you are looking at really high speed then a normal airplane is way more practical. When hogging the earth the way a GEV has to do to make use of the ground effect you don't want to go all that fast. There are a lot of things at sea you want to be able to react too, such as ships, freak waves and weather conditions.
@@OntarioTrafficMan
Kinda.
Alexeyev, who was one of the two Soviet engineers specialising in GEVs, and the engineer who designed the KM, was originally a hydrofoil designer, and he approached the problem as a naval architect, and basically thought "what if I design a hydrofoil, but instead of having the wings in the water, I'll have them in the air to avoid the water drag and cavitation".
Bartini, who designed the VVA-14, was an aerodynamicist, and basically tried to design aircraft that could take advantage of the ground effect.
I'm on the 'make it heavier' side here and think that it would make for a more stable craft since small gusts of wind or waves would have less of an effect on it. Would love to see a full-size ride-able one as well!
As for what is real and what is not, if at full power it can gain enough speed to temporarily hop into the air, that is fine because there are even a few home-built cars that can. Since it's more of a glide instead of sustained flight i'd say that the vehicle would still qualify as whatever it originally was. Also something has to be said about efficiency. If you have to full-throttle it just to stay up, while cruising comfortably at let's say 50% in ground effect, then by all means that is a ground effect vehicle.
Great work Daniel!
Colin’s soundtracks are a brilliant addition😎
One of the issues I feel is the small size and mass of your models. Wind, turbulence, waves, nature all have a much bigger impact in small craft, than on larger craft. Awrsome video as always.
Water can still have an effect on conformal coated electronics through parasitic capacitance, especially at higher frequencies. Conformal coatings are great to protect against moisture and water damage, but they won't necessarily make the electronics 'waterproof' as in 'working when submerged'.
I love how you take a theory or idea and just start experimenting whilst recording and narrating the whole process - covering and explaining all the reasons for the failures and successes.
It makes even non-RC enthusiasts like me absolutely love watching your videos.
I think the main goal of the GEV was to have a vehicle that could operate at lower throttle and therefor be more efficient, NOT "can only operate in ground effect". That was the original Russian focus, a "fast battleship". An amazing video like always, ignore the haters.
I really enjoy when things come full circle... allows you to really gain some significant understanding/knowledge. Thanks!
The "doubling down" of what this channel is and resistance to compromise to please everyone make me love this channel even more. I'm not a rc fan, engineer or have any tangible reason I should enjoy this channel. There is some nuances that make this one of my favourite channels. Keep it up. Thanks!
I totally agree with you about the power being a defining issue of a “real” ground effect vehicle. In the kite flying community we have a saying that anything can fly if you bridle it right and you have enough wind. 😁
Question: Instead of pitching the motors way up to get off the water, why not just use a small hovercraft-type fan to develop a little extra pressure under the wings. That would eliminate the transition control problem.
Weight? Aerodynamics? Any extra motor adds weight and putting a extra fan on it disrupts the flow of air around the fuselage when in flight mode. I think that VERTOL capable planes often have doors that cover any lift fans or vectored jet thrust. If I remember correctly the Harrier bleads of some thrust from the engine through vector capable nozzles located in the wings. But I'm also pretty certain they will have some way to minimize the aerodynamic influence when in normal flight. And those nozzles are a lot less disruptive than one or more lift fans in a RC model.
This isn't totally relevant, but reading your comment made me want to find a big leaf like an elephant ear, glue some sticks to it, and try to fly it.
It works for hovercraft (and helicopters, sorta) . . . .
Perfect timing for the upload! I just sat down to eat lunch and I was looking for a video to watch.
My exact situation. Sometimes life is good
Daniel.
If we go back to the Korabl Maket (KM, the Caspian sea monster) and have the information on how it was flown we can make a true ground effect vehicle.
The KM has 10 engines, 8 on the front and 2 at the back. When the KM had it's sea trials there were 2 pilots and a man on the throttles. While the pilots did their job Rostislav Alexeyev was in control of the throttles, during takeoff all 10 engines would be near max throttle but when they were in ground effect Rostislav would reduce the throttles of the front 8 engines leaving them on but just ticking over. The main thrust was from the rear engines for the actual flight.
Your GEV is being pulled through the atmosphere by two motors that can pull the vehicle in any direction and speed you want, but what if you had a motor on the front that gives the vehicle enough thrust to make a cussion of air but won't make the vehicle take off, then have a motor on he rear that gives you the forward thrust?
Once up on the cussion of air turn off he front motor and adjust your trim. The forward movement of the craft will keep the cussion of air working and you'll be in true ground effect.
When Rostislav was experimenting with scale models he had no motors on them, they were launched by a elastic band and flew for a good distance by them selves.
If you can find the documentary 'The Caspian Sea Monster ' by Equinox then you'll have a vast amount of information.
Thank you for the entertainment and see you next video. 😃👍
Great video, and a success as far as I'm concerned. I think you've shown nearly all the factors in a light weight RC GEV. Love the scenery and wildlife too.
I feel like the inherent issue here is scale.
Things scale with size differently. For example size and weight do not scale in the same way. If you made it twice as wide in terms of wingspan, its surface area (which relates to lift) would be be x4, but the volume (which relates to weight) would be x8. That's the square-cube law. I can only assume that this would then have big implications on how thrust and drag (of both the air and water), interact with each other.
On top of that you are also interacting with things in the environment that are real size. All those ripples in the water, the breeze of the air etc. while they seem small to you, they are actually all massive in relation to the tiny scale of your craft.
So perhaps it's actually physically impossible to achieve the right balance of thrust, drag and lift for true ground effect at that small of a scale.
After watching “all” of your clips, i was wondering why you haven’t made a drone rescue boat 😂😂 love your channel 👍
I'm so glad you made this, that other video with these was a such a fascinating video.
First video of yours I ever saw was the first ground affect video been watching your channel for a while and it’s cool to see it come full circle
When flying a quad I can notice the ground effect while trying to hover low. Huge throttle difference between hover 2 inches vs 6. Can get it balanced where the quad will bounce up and down without a throttle change. I wonder if a helicopter would have a stronger effect than a plane since the propeller has a huge diameter
Same! My toy Syma drone can't fly over an inch or so when voltage sags enough before it cuts off. It's like a skirtless hovercraft.
They do, and in fact ground effect is the only time when a helicopter is passively stable.
ground effect gyrocopter 🤔
@@inaoifeble Now that's just a good idea
@@21Trainman Stability is overrated. :-)
What if you used hydroplane surfaces to lift the plane out of the water and make them retractable?
I know hydrofoils and GEVs intuitively seem like a great match but turns out they are pretty much completely incompatible. I've experimented with this myself and know others that have done so as well. Even though hydrofoils have a lot of hype about having very low drag, they actually have quite a lot of drag at high speeds compared to a hydroplaning surface. They are also very picky about their speed range making it almost impossible to match an aircraft's ground speed which can vary greatly.
I had the same thought. I think the foil could definitely pop the GEV up off the water at a lower speed, but retracting the foil without pulling the vehicle back down seems hard. I can almost convince myself it should be possible, but hard to explain in a youtube comment :D
@@rctestflight wow, i never expected a reply, but yeah that totally makes sense
@@rctestflight Thats true, however he used the term hydroplane. He may have meant hydrofoil, but the hydroplane may actually be workable. Hydroplane as being a a planing hull surface.
One can suggest pontoons or skis on a suspensions system of sorts that may at a specified speed jump the GEV into the air. The thrust of the push will of course need to be angled in such a way as to not upset trim while the additional drag created when pushing down would need to be less than a value that slows it below stall speed.
Such complication of course is likely unwarranted.
A better/simpler option is the use of stepped planning surfaces with dihedral angles that soften landings and decrease wetted area as speed increases.
The surfaces carrying steps that are angled rearward to allow air to slip in behind the step. If the planing surface is like an inverse vee and the hull/fuselage is in the form of a blended flying wing. The result ought to be a sweet GEV imho.
The definition that relies on the specific purpose of the aircraft, it's intended use and general characteristics required when designing, sounds like a better one to me
Maybe something larger scale? The larger scale will not only increase the ground effect surface area to the power of 2, but it might allow for smoother flight. Currently the natural feedback keeps it only a few inches off the ground, which will be strongly affected by the waves you are testing it on. Also, try increasing the weight, as it will stay closer to the ground, and have a stronger ground effect. Doing this might make it easier to find the precise value at which it can fly, and it might save you some time. Awesome series! Can’t wait for the next :)
I think we should go backwards on the definition: if a craft can lift-off on low-power but not maintain lift at the same amount of power when very far away from the ground then it is a ground-effect vehicle.
Have you thought about having the elevators automatically adjust downwards as the motor angle increase? Kind of like how an osprey's flaps extrend/retract as the nacelle angle changes.
As you clearly demonstrated ground effect at this scale is a very delicate balance, I think one thing to consider is that obviously headwinds etc greatly disrupt that balance, and the flight controller currently has no way of compensating for that.
An air speed detector on the model allowing the controller to instantly adjust for variations in lift from airspeed fluctuations could give good results.
Great series and looking forward to more.
Another great quality video. You are among the very best youtube content creators!
The Caspian sea monster took all but two of engines to get off the water they shut down all of them except for two on the tail when they were flying in ground effect
First, let me say how I've enjoyed your channel through the years, and your content is getting better and more sophisticated with time and experience.
Second, I wouldn't listen to these internet armchair physicists if I were you. They take pleasure in pulling the rug out from under others.
Even free entertainment is not good enough for some. Don't let them get to you. They are a single digit minority I can assure you of that.
You do you. I love to see your creations.
Beautiful, loved the tech stuff and Insta 360 footage. Keep it up!
Very interesting, thanks so much ... and I am even more interested what I can see in the background 15:10 a large solar RC sailplane !!!
16:02 ... the wall in the background speaks for itself 🙂
I saw it too!
The Caspian Sea monster could fly at 500ft
First
🥇
Extreme respect for your hard work and dedication to scientific principles. You are expanding people's knowledge. All that said, I'm still going to shift the crown to the first creator to do this at high wing loadings keeping in the spirit of why ground effect was necessary to meet the objectives. Probably nobody will put in the effort. This will properly be accomplished 50mph or above. The trinity of area, loading and power all together.
12:05 I love that these videos typically have almost some kind of "Limitations" section, like you would in any good research paper.
I used to teach at DIT, on the boat at 9:22. It’s cool to see you out on those waters.
In my limited experience with GEVs, I found that having a really small wing, with a high tail mounted motor - elevator combo (no par thrust) worked well. Needed quite a long run to get up to speed but once in ground effect it flew pretty well, it couldn't turn much though.
Been looking forward to this!
As a mechanic when I went through school they taught us that it was high pressure under the wing. The wingtip vortices can add stability but they can also take it away. The main work is done by the high-pressure pocket underneath the wing and the low-pressure pocket above the wing. Being as your ground effect vehicle is all lifting body it is allowing a high-pressure pocket to be trapped underneath the body and the pylons help to focus and stabilize. Good CG because this is a highly stable craft!
Also I would argue that a slight airfoil shape could improve the ground effect. The whole point of an airfoil is to reduce the pressure above the wing as opposed to the pressure below the wing. This is because laminar flow causes the air to follow the skin of the wing and the wing has more skin surface area above than it does below. The higher surface area causes the air to have to linger on the skin of the wing causing a low-pressure pocket. The faster moving air on the bottom of the wing creates a higher pressure pocket.
I randomly found then subscribed to this channel through the youtube algorithms and I’m glad I did. Great channel.
Great work! You did it! That is so awesome! Great series!
Nice job addressing everyone's concerns, and finding not just that sweetspot but the right form to find it.
Thanks for the great vids
I remember the video on your pond years ago. Outstanding remake!
Finally! It is mesmerizing seeing it fly so close & smoothly over the water!
I keep wanting to build a full scale ground effect vehicle but every video you do it puts into perspective of how difficult it is! Keep up the good work
Been waiting for this one, Great vid bro
I came into this and your previous video thinking that I understood things pretty well having learned about ground effect through racing and formula 1, where ground effect plays a major role in making the cars faster through corners by pulling the car down to the ground and thus giving the care more grip. I have spent the last ten minutes trying to apply these principles and my, what I now recognize as limited, knowledge to this concept of a flying ground effect vehicle and I have been thoroughly confused and amazed.
I was waiting for the song the whole video, great video btw
I did mechanical Engineering Diploma Project under the Title "Analysis of a configuration for ground-level flying". I wanted to build a 1m wingspan Ekranoplan-type RC-Model, but our wind tunnel at the university only had a 1m diameter nozzle, so I had to build a half-scale model and measure at double the airspeed to achieve the same Reynolds number.
The goal was to find a configuration that would allow a speed window of around 5km/h in which the thing would neither want to land nor take off, but remain in stable ground effect flight.
The Problem: when a wing nears the ground, its pitch moment turns forward, i.e. reducing angle of attack and effectively pushing the WIG (Wing-In-Groundeffect) craft onto the water. Therefore Ecranoplan-type WIGs require a large horizontal stabilizer with a lot of downforce, and so high up that it stays well clear of ground effect. My original horizontal stabilizer turned out to be too small and have too little downforce, and too little moment arm, meaning it wasn't as far back as it should have been. I realized this a mere 4 weeks before my time ran out, and now had a configuration that would either just take off or land :-(
Frantically I made a much larger horizontal stabilizer with negative Clark Y airfoil, as I had no time left to increase the moment arm of the thing. Thankfully this finally gave me a ground-effect window of just shy of 4km/h. Which means every little breeze or turbulence would lead to take-off or landing. But I HAD found a configuration for a true WIG craft, which is not defined by weather it is capable of free flight or not, but that it has a large enough speed window in which it is in stable ground-effect flight, without all the modern gizmos of Lasers and electronic stabilization :-)
You definitely have a career in wildlife photography! Thanks for another great video!
This was fun! I love your planes. Can't wait for the next autonomous boat installment if you end up doing that again
I love that you were researching the GE vehicles by watching Peter's vid, who then references your own vid. Like, neat, but also dangit.
Also, a future project suggestion might be to build a reliable rescue boat to go retrieve failing watercraft heh. That kayak seems to be getting a bit of use.
Super good video as always, it’s so nice to see all these improvements so it flies more and more like a true ground effect vehicle. In flight principles in flight school ground effect is studied and it is said to be the resultant of the wing tip vortices “breaking” in proximity to the ground. Therefore reducing lift drag and improving lift as less air “escapes” the pressure gradient between the top and bottom of the wing through the wing tip increasing lift. This is caused as there is a greater pressure gradient between top and bottom side of the wing as no air is “leaking” through the wing tip. So another approach to creating a ground effect vehicle would be to tweak the wing design so that it doesn’t have enough lift to sustain flight but would in ground effect with the increase in lift (and the reduced induced drag decrease). Keep up with this videos love to see such good quality!!
Glad to see you return to one of my favorite GEM videos.
Loving this series. My 2c is that while your aero design is good, you also need to pay attention to hydro design when on the water, so that you can accelerate faster and then have less surface tension holding you down. Your square floats are causing huge turbulence under the wing when you need that water smooth. Look at the chines on a motor boat or even flying boat.
Your videos have always been great, now they are heading to legend. Well done
Also this seems like a job for a LUA script to detect take off and pitch the motor's
Hey Daniel! I recommend that you put sort of bumps into the tips of the wings because it would make it turn smoother and make the plane still glide over water without having to gain more altitude and still be really stabile. I hope you see this and try the idea. You´ve done a great job overall. Keep the great work up as always!
This is super interesting ! I really didn't think it was possible for the rc scale ! Well done !
This channel is one of the best for demonstrating "Rapid Prototyping" using easily obtainable & cheap materials and electronics to work through your designs fundamentals. "You Sir are a gentleman and a scholar!"
Conformal coat definitely lets water through. It's used to keep stuff dissolved in the water and other conductive material out. If the board under the coating isn't absolutely clean the water coming through the coating will interact with the contaminants to conduct. Contaminants in this case includes things like the residue from the solder flux, including no-clean flux. It's really hard to get it out from under the SMT components.
For waterproof boards you will need silicone potting. But you still have to leave the connector pins uncoated. Parylene coating also works, but that requires deposition in a vacuum chamber.
the main thing to remember with a water based GEV is that its a boat first. The more efficient you make the hull from a hydrodynamic standpoint, the better GEV it will be. you will need less power to get speed, which if you design the wing part right, should trap enough air at a specific speed to finally liberate the hull from the water with just enough lift to keep it right over the surface. Lookup a boat called the flareboat from the 90s. it had a BMW motorcycle engine mated to an air propellor, it did around 70kts. it was marketed as a fast efficient way to get around the islands when the waves are rougher, without needing a bigger boat or a pilots license.
Your time is greatly appreciated love the content
If I recall correctly, ground effect was supposed to be used for efficiency. You need a lot of power to get off, but then you can cruise along faster than a boat but with more efficiency than a plane. You can also carry a lot of weight more efficiently than a regular plane. The scientists who came up with the huge soviet ground effect plane visioned it to be the future for carrying heavy cargo accross vast distances with the best efficiency/speed ratio.
Absolutely love this video!
On this one your elevons are on the outer horizontal stabilized, that means with up elevator you have a washed out wing! That converts it into Bell Shaped Lift Distribution wing!
The forebody causes the Outer Horizontal Stabilized(wings) to fly in an upwash OGE.
If it's set at Zero incidence it will not produce much lift IGE which will case a forward shift in Aerodynamic Center.
Out Of Ground effect they produce lift causing a pitch down and the tendancy to remain IGE. Hope that makes sense
Such an awesome series of videos 👏👏
In order to make the power to weight ratio worse you could also add ballast. Compared to a full size GEV your models are probably super light, a significatly heavier version might also be less sensitive to wind and other factors
The thing is, if it can fly more efficiently in ground effect and is designed to, then it’s a ground effect vehicle. The original massive Russian ones could jump bridges using full thrust from all their motors but they couldn’t climb very much and then switched back to 2 motors to sustain ground effect. Another idea of this is a big off-roader with 37 inch mud tires and a 4 inch lift, it’s designed to be really good at off-roading but it can still drive on the roads and that doesn’t mean you call it a car because it’s designed to go off-road which means people call it an off-roader. So in my opinion your first ones were ‘real’.
Others have said it but it deserves repeating - Any scaling issue can be addressed in more than one way. Rather than reducing power, add weight. The biggest difference between RC craft and full sized craft is often wing loading. It makes sense to reduce that difference.
Another way of thinking about it is to examine the scaling effects on different parameters, such as wing loading, span loading, weight, wetted area (literally), etc.
Nice Work.! All self built and it work fine.
Its so interesting to see the oscilations on ground efect the same as current F1 cars have something they call "porposing" (its the same thing) but they try to have as much downforce as they can using ground efect.
I beleive you finally did it!
Ideas to consider: Use a hydrofoil that telescopes up to reduce energy needed to lift body out of water. Paint bottom of the vehicle with hydrophobic coating to reduce droplets clinging on to the body. Consider a voltage limiter circuit between the battery and the PWM dropped to something below your minimum battery output to prevent the difference between a fresh and near empty battery.
I like the change in altitude at 4:35 when going over that boat's wake. Clearly the ground effect. BTW the bird at 7:24 is a cormorant - they can go underwater for quite a few seconds looking for a snack.
Awesome job. Excellent work.
I'm alway so exited when I see a new Video of you. XD
for definition: if it is designed to utilize ground effect, it is a ground effect vehicle, almost any gev is actually a plane, that designed to utilize ge and can use it to make some special action with it, mostly to travel way farther than it could in either ship or plane mode.
This is quickly becoming one of my favorite channels.
Nice experimental vlog there. Experimenting with the profile of the floats might reduce the power needed to initially unstick from the water surface. Look at the developement of the flying boat hull for how things have developed from flat bottom floats to boat like hulls.
The shots from the wings at dawn are awesome !
I remember, as a kid, reading of a B-17 crew returning to England with battle damage and down to two engines. By throwing everything overboard they were able to maintain altitude but then lost another engine. The B-17 could not remain airborne on one engine and they prepared to bail out before they got too low. But the pilot had the navigator calculate their descent rate and asked if they could make the Channel. He said they wouldn't but could make the North Sea if they turned due north. Pilot told crew to not bail out as he turned north. The plane settled to about 10 feet over the water and held. He gently rudder turned west and eventually belly landed on a beach in SE England.
I have been flying for 38 years and I have never flared for landing as the gentle hand of ground effect reaches up to help without thinking of that B-17 pilot who bet EVERYTHING on it. I generally fly high-wing aircraft and ground effect works out very nicely. When flying a low wing aircraft, if you are carrying ANY extra airspeed you find yourself wishing there was a ground effect switch you could turn off. Turns out yelling. "Stop flying, FFS" does very little. I also learned what I what I think is the other reason sailplanes have spoilers. A sailplane with enough energy to fly at all becomes a perpetual motion machine in ground effect. 62' wingspan, altitude 3 feet. It will not quit flying. I think ever.
Come for the rc projects, stay for the music!
Another thing you could do is flatten the top surface of the wing so it doesn’t act as an airfoil (parallel to the wind direction). That will create a zone of high pressure under the wing but no zone of low pressure on top. It will then be much harder for it to fly out of ground effect.
Water doesn't need to touch your electrical conductors on the PCB to mess something up. It can lay on the right spot(s) on top of the coating and act as a capacitor, which can attenuate high frequency signals (among other effects). This can affect transcievers as well as processors.
One thing you could try to make the problem solve itself over the course of a few minutes is to add a small heating pad under your electronics. Not sure if this will help with big water drops, but it worked for me for my outdoor Radioduino-powered solar station (condensation messed up the transciever). Keeping the transciever module about 3-4°C above ambient was enough to keep it working.
Many years ago I read "The illustrated guide to aerodynamics", and from what I remember, the wingtip vortexes cause induced drag and when the plane is in ground effect these vortexes are interrupted and that eliminates induced drag and thus makes the wings more efficient. I don't think the author believed in a high pressure cushion of air causing ground effect, just that the wings gain efficiency in ground effect. Granted he was only discussing airplanes in ground effect and I can see that the way air is channeled under the wings of your purpose built ground effect vehicles that the high pressure air pocket makes sense. I think it would be interesting if you added ballast to make the plane heavier.
always a fan of Colin's work
ok make one you can ride in next 💯
Goals! Step 1: rent warehouse
Conformal coatings are not intended for primary protection - it's a backup. Things like connectors can't be waterproofed with it anyway, so you always have point where water can effect. They are intended for "backup protection" generally.
You got to what I was shouting at the video all along at the end. I’d love to see that plane with a bunch of ballast on it. I bet with full power you could find a weight at which it will only ground effect.
I think this is absolutely the right approach to research this effect.
Do not get hung up on the half a wing span definition because it is the air cushion that matters so it no doubt follows an area rule not just a span rule.
Add weight instead of reducing power. Adding weight and running the motor at its rated kV will be the easiest way to…oh wait you just brought this approach up so DO IT!
I think if you had a mix for elevon down with the motors pointing up it may make it easier to focus on throttle control. On an underpowered vehicle pitch can drastically change airspeed.
Just my thoughts but I think your exploration on this topic is quite interesting. I am curious about this kind of exploration moving more into the performance/efficiency direction myself. I think focusing on the "definition" of ground effect is kind of a distraction from the coolness of making a truly high performance craft that performs like a sports car in air close to the ground without the drifty-ness of a hovercraft is king here. Most airplanes are crazy unstable close to the ground and mastering the ground effect to maintain stability or even improve it is extremely awesome. Very inspiring work, I hope to be able to reach this level of experimentation in my own projects at some point. Right now I am still trying to catch up to your knowledge level to hopefully get to experience these kinds of projects first hand. Thank you for the inspiration!
The footage of it flying over snow looks cool
Actual pro tip for conformal coating electronics: Most conformal coatings have a UV tracer in them to allow inspection. Get yourself a cheap UV LED torch and you'll be able to see where the water's getting in. (Get yourself some UV curing glue while you're at it, very useful stuff).
The shot of the craft in front of the Divers Institute vessel is top notch.