Airplane + Hydrofoil - Good or Bad Idea?

[@pfidze]

Come for the science and action stay for the awesome tunes at the end

[@runklestiltskin_2407]

Reminded me of the Jeffrey Bezos song by Bo Burnham.

[@victorchristophersen3601]

kzbin.info/www/bejne/pnqZmnlsqrZ7mdk 🤣same🤣

[@Oroborus710]

@@runklestiltskin_2407 that's the song they based the one at the end of the video on lmao

[@MrCarlozan96]

Always

[@daniel.mackin]

Hydrofoil, ***k yeah!

[@kwaaaa]

Truly impressed by Daniel's ability to find every lost or crashed plane, wing, drone or camera.

[@i-_-am-_-g1467]

Established titles is a scam and the Ekranoplan did it first

[@SkashTheKitsune]

criminal investigators should take note

[@theperfectbotsteve4916]

He's like a airplane blood hound

[@codys925914]

"Established Titles" 1. No land ownership 2. No legal name change 3. No proof trees planted in Scotland 4. Pricing indicates product is real D) 5. Upon checkout, buyer is automatically subscribed to a monthly fee 6. On website, they talk about no land taxes in Scotland, inferring you own the land 7. Company owns two other brands linked to scams 8. Company lists an office in Scotland but no office exists, they are in Hong Kong 9. Company personally attacks critics 10. Ads use words "legally", "officially" and "formal", none are true 11. Website verbiage changed after being accused What else does anyone need in order to realize this company is predatory and highly unethical?

[@codys925914]

Truly unimpressed Daniel is promoting a scam.

[@codys925914]

"Established Titles" 1. No land ownership 2. No legal name change 3. No proof trees planted in Scotland 4. Pricing indicates product is real D) 5. Upon checkout, buyer is automatically subscribed to a monthly fee 6. On website, they talk about no land taxes in Scotland, inferring you own the land 7. Company owns two other brands linked to scams 8. Company lists an office in Scotland but no office exists, they are in Hong Kong 9. Company personally attacks critics 10. Ads use words "legally", "officially" and "formal", none are true 11. Website verbiage changed after being accused What else does anyone need in order to realize this company is predatory and highly unethical?

[@Antirrhopus]

daaaaaaaaaaaaaaaayum thats wild, thanks for the info

[@fluppet2350]

It’s because people don’t actually look into their sponsors. I’m surprised it took so long for someone to look into it and find what’s wrong with it. Although we will give this guy a little slack since the expose was about a month after this video was made.

[@Eckus]

Wow thats realy bad xD but the realy bad thing is that this youtuber promotes them LOL 😮

[@anotherfreakingaccount]

@@fluppet2350 slack or no slack, it indicates he didnt look into his sponsors. I came across this company years ago and thought it seemed cool, but after a 20 minute google search it was clear they werent legitimate. Whatever "expose" happened recently wasnt necessary to see through their ruse

[@oldschoolcfi3833]

The Line through the Clouds is called a Distrail - or dissipation trail, the opposite of a Contrail - or Condensation trail. Both have the same cause - heat and condensation nuclei from the engine exhaust creates localized areas where the water vapor is condensed into tiny ice crystals or water droplets. In the Distrail- the effect creates larger droplets from already condensed mist (the cloud) which are large enough to fall away, leaving an open lane in the cloud.

[@douglasdippold8235]

No, it happens when the plane is sucking up water to mix with its stores of dry chemicals, so it can continue in its mission to leave chemtrails. You know, to poison us or drug us into submission or whatever it is the nutters say they're doing.

[@GregorShapiro]

They just didn't have their Chemtrails pumps going !

[@walterpark8824]

Good to know....

[@ahaveland]

The distrail was caused by an earlier plane in a different path, not the one at 21:34

[@FourthWayRanch]

no it's not, it's from the chemicals they dispose of in jet engine fuel, read about chemtrails

[@lesumsi]

I always enjoy your little side quests, like finding a submerged camera :)

[@stefanonegrini4675]

the level of details and depth in those projects is always stunning.

[@Daruma_Studio]

"Depth"? I dunno man it looked pretty shallow to me... 6:40

[@stefanonegrini4675]

@@Daruma_Studio from a little beam shaped object, that must be like the Matianne Trench tho...

[@shurmurray]

My 5 cents about sharp foils: recently I dove into hydrofoils thing too, designing impeller blades for waterjets. And when I was about to use some basic airfoil I suddenly found the airfoils for water are actually different (surprise) from airfoils for the air. The main reason is the cavitation. And the other reason - much higher water resistance: many hydrofoils do use sharp leading edge. Anyway - within working range of allowed angles of attack (usually something from -13 to +13 deg.) the sharp leading edge works ok.

[@pawelrelidzynski680]

Was about to say that, due to the viscosity of water, a sharp leading edge is better. Look at boat/yacht shapes the sharp edge is at the front, contrary to airplanes where the sharp edge is at the back.

[@BlueIron64]

@@pawelrelidzynski680the sharp bow angle on boat hulls is meant to reduce the bow wave created at the interface between the air and water. Torpedos and submarines use rounded fronts because they are fully submerged

[@pawelrelidzynski680]

​@BlueIron64 i get your point, but that is not entirely true. You can see some bigger ship types being rounded in front and thats due to the speeds they travel. In water there is less resistance with a pointy shape in front, and i have seen it in a controlled environment. Same with air, less resistance when the frontsurgace is rounded and pointy in the back

[@squeakybunny2776]

"so that's why we can't have sharp hydrofoils" I think what you meant to say was:"so that's why we need to make this thing supersonic" 👍🏻

[@Biggerman159]

Video: this video is sponsored by established titles Me: *run*

[@FowlerAskew]

I've gotta say it's really nice to have someone to watch who just researches and tests things for the fun of it, it really keeps me motivated to just work on things that I think are interesting

[@Space_Reptile]

a little suggestion for the drone that went in the water: spraypaint the waterbottle a bright color so its very easy to spot when upsidedown in the water like that or fill it w/ expanding foam, so incase it is damaged it does not sink whilst also being more visible

[@kungfuhskull]

Good suggestion. As color I would recommand a bright orange or red. If something samller would be wanted maybe the mechanism of an automatic life vest could be copied.

[@arlenn729]

Also, a small LED light inside the bottle would be a good idea. It doesn’t add much weight but will provide you several hours of super accurate positioning.

[@ezrarichardson279]

@@arlenn729 yeah. That would be kinda sick

[@skenzyme81]

The transition from hydrofoil lift to flight on the Regent aircraft seems to depend on a pitch-up "launch" to get more lift by increasing the angle of attack. While this might work, passengers might find such a maneuver more than a little unsettling.

[@06howea1]

its useless

[@jbirdmax]

I noticed that. It looks pretty jarring unless they have some special seat suspension that can enter the cargo area.

[@FlyXenonRC]

@@XenoWiz more motors does increase the safety in case of a failure

[@inventor121]

@@XenoWiz more motors actually generate more power than a single big motor due to tip speed limits. If your tips start hitting the sound barrier they won't generate as much thrust and will generate a ton of drag. As such you can run a smaller motor at much higher speeds and have more of the blade in the "optimal thrust region" For electric motors having a bunch of smaller motors has major benefits, the first being that you don't need to put huge amounts of current through a single wire (fire hazard). The second is for motor cooling, third is cost (a bunch of small motors is cheaper than a single big motor). The Blown Wing isn't a new technology, it's been used for decades on drones and has a long history with STOL. It actually does work since the effect of the wing is independent of the ground this allows for a functionally higher airspeed over the wing than your actual groundspeed, it's like taking off into a headwind. Momentum is conserved since the lift and thrust are (mostly) perpendicular to each other. The reason why airplanes traditionally favoured having one or two big engines is because that was also their main powerplant. ICEs are big and heavy, their power to weight ratio is actually very low compared to electric motors (batteries and fuel not included). Gas turbines have a thrust to weight ratio comparable to electric motors. So why aren't electric motors used in aviation as much? Well batteries are heavy, much heavier that fuel, and that tends to be the deciding factor. And jets generate just so much power so easily that it's kind of dumb not to use them despite their complexity.

[@BikingVikingHH]

Yeah, you dweebs are just noticing a particular movement of a test vehicle and trying to extrapolate it into an inescapable aspect of the final product’s operation. Nice try dorks. The reason why the flying boat has hydrofoils is exactly to *prevent* what you geniuses think it will cause; jarring vibration/shock. A normal flying boat rides on the surface of the water, planing before it rotates. That means that the roughness felt by the passengers is directly related to the roughness of the water’s surface. If a seaplane has hydrofoils, it can quickly lift off *above* surface irregularities, causing a smooth ride as it builds enough speed to rotate. The only time you’d feel the rough surface/waves is at initial acceleration stages when the speed is low and affect on the airframe minimal. Basically a little rough right at the beginning, then transitioning to an incredibly smooth hydroplane affect, followed by a rotation that I’m sure can be modified in it’s severity. They probably just made it look like it was “jumping” out of the water for a cool promo video. Y’all really need to look at the big picture, how the entire machine operates, and not just autistically and pedantically notice one single aspect and think your assumptions are that of a smart person….

[@doctaotsu]

I've learned so much from these videos but... I'm not going to lie, watching you recover shit you've lost is one of my greatest joys.

[@tracybowling1156]

You're so knowledgeable about flying and boating that it makes the episodes fascinating to watch. I like when in some episodes you get super excited. It feels infectious! 👍🏻

[@kinderdm]

In regard to what you mentioned on the jet. Why wouldn't skis be the ideal solution to most of these problems? At low speed the waves aren't an issue on the hull. At higher in water speeds the skis will plane, lifting the body/wings away from the waves. And then at highest speeds, when your airborne, then the skis could be retracted like landing gear against the body for a smooth hull. This seems to give you the best configuration for all three speeds for takeoff/landing transitions.

[@wiegraf9009]

Skis would induce a lot of turbulence and drag but yeah if they were retractable it seems like a good idea. I just wonder if they would really help ekranoplans with the choppy water problem because they wouldn't be very useful at cruising speeds?

[@nikpudhota]

I learnt from one of your videos that I can replace the battery on a Dyson vacuum. This saved me from buying a new one. Thanks mate!

[@surfcello]

This is the video I've been waiting for for ages! Your closing remarks are the most valuable to me: 1) Hydrofoils could help get GEVs and seaplanes out of the water, and perhaps aid in landing. 2) They'd have to be retracted to make efficient use of GE. 3) This bonus is not present at RC scales (likely due to smaller mass to surface ratios and lower Reynold's number). This had indeed been my hunch, but I'm so grateful to you for actually doing these tests and giving your expert's opinion. My motivation for the idea has always been the tell-tale fact that the Ekranoplan allegedly used 8 turbines to take off but only 2 for sustained flight. Perhaps one could also improve efficiency at sub-takeoff speeds by propelling the craft against the water rather than the air - e.g. by a mounting a boat prop to the back of the hydrofoil, or by creating a water jet with water sucked in through a hollow foil.

[@wiegraf9009]

Jet powered take off ekranoplan sounds extremely badass

[@collinkaufman2316]

​@@wiegraf9009the giant ekranoplan did that and then fly the entire thing with only 2 turbojets

[@FilosophicalPharmer]

Really great video as always, Daniel!! Thanks for including us in your projects 👍🏼Glad I got to hear your friends’ sweet tunes also! 🤘🏼

[@RegisMichelLeclerc]

Hi! I was so happy to see my mug in the "instigators' list" 😊 Thank you so much for making all the research and the tests. As you suggest in the discussion, hydrofoils would need to be short and possibly retractable (although they provide a tiny amount of lift in the air too, with some added instability). The goal is to leave the water as soon as possible to make the transition to and from airborne as fast as possible, especially in choppy waters -- the goal is to fly over the sea, which is *never* flat, even in a cove. From what you show and the Regent experment (I wasn't aware of this one), you'd use T-foils as they seem to provide more lift and less drag at low speed, and more than just one at the front spread around the CoG (i.e 1 ahead and 2 on the sides behind, or 2 and 2, adding to the same surface). Currently, I'm more on the Lippisch design (inverted delta) with 12º anhedral to which I add canards, the idea being to add 1 hydrofoil under the fuselage and 1 under each of the floats located at the ends of the wings, so to transition as quickly as possible to airborne. So far, the canards are attached to a nacelle at the front (like big ears on the head of a flying duck) because I wanted to have wings swept 30º forward (making an skirt open 120º in front), but I probably drop that to no-sweep and have the canards attached to a straight edge so to modify the entire wing geometry by moving the canards'edges up and down. Thank you again for all the work and the actual experimental results you provide. Keep up the fantastic job!

[@o-manthehuman7867]

16:20 looking at it, I'd say that it's almost certainly possible to land it without stalling at 52kts-- taking off would be more difficult, but the ground effect should help it reach the speeds it needs (for example, in soft field takeoffs, we lift off much sooner by applying full back elevator pressure-- however, once in the air, we immediately let off pressure, and stay in the ground effect until rotate speed). I'm pretty sure that plane's wingspan is long enough that it can be in ground effect without the hydrofoils being in water, so I imagine that's how they'll do it.

[@keithcress1335]

Outstanding! Thanks for teaching me about ventilation. Never heard of it before though I've seen it before while not recognizing it as anything. Amazing footage between the drone and the ground effect "napkin"!

[@patrickmulvany6479]

Just a gut feeling - when there is no physical connection between an air cushion vehicle and the water, there must be less drag than if you dangle some shape, any shape down into the water. Your interesting experiments proved just that. The air cushion principle is so elegant in its simplicity. One hypothesis I'd love to see you try is fencing - i.e., Run a raked vertical fin down into the wateron the rear inner faces of your sponsons. Seems to me that you could extend the cushion of high pressure air further back, negating form drag from any horizontal surface touching the water. My theory is that fins would yield two benefits - first, lower form drag, and second, better lateral stablility. I'd love to see you throw some fins on your mature research aircraft!

[@Minty1337]

11:55 "that's the cutest little tugboat i've ever seen" 3D benchy in real life

[@Nishye501]

FYI established titles is a scam you’re better off just giving directly to something like one tree planted

[@bjrn-oskarrnning2740]

Just to save you some money in the future: the steel you buy usually isn't hardened, so high carbon steel isn't harder than regular steel (mild or construction steel) unless you actually temper and aneal it. Not that it matters a lot in those quantities, but tool steel is about twice as expensive as mild steel :) Additionally, brazing might be a better (easier) way to to attach pieces like that without sacrificing much strength. Anyway, awesome and educational video as always!

[@FiltyIncognito]

PSA: Be cautious about what craftsmen/tradesmen tell you about heat treatment. Many of them are notorious for getting it wrong because they tend to learn by word of mouth and trial&error rather than reading about material science. And we all know how the game of telephone tends to go. Heat treatment is a science. A branch of material science, to be exact. And it's complex enough to require highly educated and dedicated specialists when doing R&D for big expensive projects. Anyway, annealing undoes tempering, and tempering improves strength, not hardness. Quenching fast makes it hard, though also much more brittle. Tempering reduces brittleness whilst retaining higher hardness than other processes, which ultimately increases its' overall strength. Coincidentally, that metric is called 'ultimate strength', which is different a completely different metric from 'hardness'. Look up the tests for measuring those two. Annealing is the process which kind of 'resets' steel, typically used to maximize machinability (make it softer/more easily workable) and remove internal stresses due to forging and machining processes. It's also typically quenched more gently so you aren't left with an overly-brittle product.

[@FrederikConradie1986]

Mr Daniel, I'm glad to see you again in my top video suggestions, its been a while. :) Hey, also, thanks for your previous videos on the auto gliders and solar planes etc... I'm almost done building up my ASW 28 for the auto soaring via ArduPilot, same as you did. Keeping on doing your thing, its top tier!

[@pjz7088]

Hey I'm in a video, cool! Thanks for the mention. Excellent exploration of the concept! It's cool to see the historical applications of the tech, so thanks for including those. Ventilation is the WORST when winging, I think that's the appeal of high dihedral front foils, although you rarely see it in rear stabilizers. I'm sure you've done plenty of research while making this thing, but if you want to get into hydrofoiling, there's plenty of money in the industry now, particularly wingfoiling, since it's the new hot thing, so lots of watersports companies have been investing in research to create the best hydrofoils. It's neat to see the differences in performance, high/low aspect, lots/no dihedral, thick/thin wings. I was toying with the idea of creating a biplane style hydrofoil, where the lower wing is smaller, creating less lift, but less drag to provide a gradual transition to flight, but you've proven pretty well the combination with ground effect aircraft isn't super compatible. Well done, keep playing!

[@harken9978]

you should look into supercavitating hydrofoils. I reckon you'd love em! Im currently developing one for a high-speed foiling windsurfer down here in the choppy waters of the Swan River

[@ma-haelli-ham3546]

Someone may have mentioned this but there are hydroplanes that use cavation to produce lift. They have sharp leading edge with square traling. The fastest sail boat uses one.

[@old_guard2431]

Found mysel

[@old_guard2431]

. . Myself wondering how cavitation fit into the equation with hydrofoils.

[@InterFelix]

Please dump sponsors like Established Titles (others that come to mind are Kamikoto or RAID Shadow Legends). They're effectively scamming people out of their money. Sure, it's only a novelty gift, but charging 50+ dollars for absolutely nothing (maybe a single planted tree) is still a scam. Kamikoto is actually part of the same parent company, although they sell actual products under false pretenses (shitty mass products that they claim are handmade quality products).

[@AerialWaviator]

Drone down 18:41, 18:46 Camera drown 7:02 Hydrofoil frown 13:01 Daniel not messing around, for he's no clown.

[@TheRealWulfderay]

Daniel, I am always amazed at how much science and education you pack in your videos, but ngl my favorite part is always the music videos at the end. So lucky to have your own personal musician! :D

[@rafaelthetall]

if you have a multiple stage hydrofoil: the bottom one, smaller, pulling down, and a bigger that would skim the surface, perhaps with a mechanical 'feeler' that would auto-adjust the height?

[@Kruglord]

Great video! I'm curious, have you tried a "fan wing" design before? It would be cool to see if you could combine the ground effects stuff with the supposed "ultra-high efficiency" and short take off distance that the design proposes. They're not capable of high speeds nor high maneuverability, but I'd like to see how efficient they can get.

[@OmicronMite]

Why I love this channel: *says something super technical I barely understand* and then “woah that cool boat has a crane”

[@rubenwardy]

Good video, the ventilation demo was cool. Established Titles is a scam though and you should check sponsors better before accepting them

[@fpvgods]

That ventilation demo just before 10 minutes was really cool so thank you for doing that.

[@NZobservatory]

"What has he built _now?"_ -- The birds of Washington state

[@daylen577]

8:00 This is so fascinating. It's like how a truck has better fuel efficiency with the tailgate up even though you'd think that would produce drag, but it actually doesn't as it's designed to create a pocket of turbulent air that the other air just flows around. Driving with the tailgate down removes a tiny bit of theoretical drag from the tailgate, but adds more drag around it because it gets rid of that pocket.

[@Ilovepie_05]

Established titles is a scam

[@Thebananapresedent]

Why

[@nopel.]

Why

[@GibDib]

Why

[@obvossy4433]

Why

[@krinos1]

@@obvossy4433you don’t actually get anything. You arent a lord or anything and you arent buying land or whatever

[@chadparr1864]

Just the fact that you was able to find that camera deserves a subscription

[@kevinattard4520]

I love the evolution of these ground effect vehicles…

[@paranoiia8]

Best example of book/internet knowledge and actual knowledge. Lots of people think they know stuff because they read about it, but real life have its own rules. People love to comment trying to correct someone or give suggestion when they never saw or try that in real life by them self.

[@DogeMultiverse]

Now we just need a helicopter that runs on ground effect

[@Avetho]

Wouldn't that just be a -leg- _hedge-trimmer_ or something? XD

[@collinkaufman2316]

Isn't that a hovercraft?

[@AgentWest]

Wonder if having a different wing profile would be better for hydrofoils, maybe even capturing the ventilation/cavitation air bubble and using it for lift. I know there are some boats with flooding compartments (flooded when not moving, for stability. Empty out as the boat starts to move for higher speeds.) Applying this concept to a hydro wing make me think of basically one with a front slat, but the slat is attached at the bottom. Or just a channel slightly behind the top of the wing profile. My thinking is that at speed this would create a pocket that would either just help with lift, air is lighter than water an all that, or serve as a vent to bring the gasses along the foil and out of the water, away from the wing itself.

[@OurCognitiveSurplus]

I need to go to sleep, you can’t upload now

[@linecraftman3907]

haha I already slept

[@RAD-RC]

Ha I just woke up

[@carsonhanson243]

Literally 😭🤣

[@undersky596]

Feel that one

[@Thisoneastronaut27]

Its daytime dummy

[@StanVanGundy1]

That camera searching cut scene was epic

[@u982245]

Established titles is a scam , please stop pushing this scam

[@blahbaconblah]

This is the first RC controlled sushi producer!

[@xpeterson]

So, hydrofoils get less efficient as they get closer to the surface, but airplane wings get more efficient the closer they are to the surface, and race cars produce more downforce the closer they are to the road… Fluid dynamics is weird

[@caydenhoff8998]

There are hydrofoils that use supercavitation. This is just forced cavitation at higher speeds and can increase both top speed and efficiency. I think the largest benefit to adding both ground effect and hydrofoils into one vehicle would be it’s very high weight capacity; high weight would also help with the foil staying close or in the water… last thing, foils can also be used to pull the craft towards the water preventing the bouncing created with ground effect.

[@yvanpimentel9950]

wingtips downward so at low speeds it toch the water negating a way out to the air

[@BikingVikingHH]

The reason why the flying boat (Regent) has hydrofoils is to prevent jarring vibration/shock; A normal flying boat rides on the surface of the water, planing before it rotates. That means that the roughness felt by the passengers/airframe is directly related to the roughness of the water’s surface. If a seaplane has hydrofoils, it can quickly lift off above surface irregularities, causing a smooth ride as it builds enough speed to rotate. The only time you’d feel the rough surface/waves is at initial acceleration stages when the speed is low and affect on the airframe minimal. Basically a little rough right at the beginning, then transitioning to an incredibly smooth hydroplane affect, followed by rotation. It actually makes a lot of sense. Same thing with landing; land on the hydrofoils, then by the time the plane decelerates enough they don’t generate enough lift to lift the airframe above the water, the plane is going slow enough that the rough water won’t be too abusive to the airframe.

[@carveroutdoors]

Always appreciate when you include information about aerodynamics; I didn't know about the foil shape stagnation point and you always do a great job simplifying it! Thanks for another great video sir!

[@ahowl7mx]

I always thought about building one of those, except my concept was sort of a airplane with legs where the lifting body (passengers and pilot) is in front and the waterski/foil part (power source) remained attached to a surface on a sled.

[@VegasJD]

Wouldn't the vertical part of the foil need to be longer than whatever sort of optimum height of the ground effect vehicle is? Seems like that would help anchor the vehicle at its' optimum height?

[@Dave27138]

The Foil has to be on the back of the plane like a wingfoiling board

[@faragar1791]

What about the Sea Dart's water skis? They don't appear to use a foil design to gain lift out of the water. How efficient would skis be for amphibious aircraft?

[@old_guard2431]

Fascinating video. Essentially the lack of water pressure differential in the couple of inches the foil pierces the water for a model robs the model of the lift increase provided by the feet a full-sized foil pierces the water. The main advantage of the hydrofoil is the ability to maintain a higher speed in moderate sea conditions without pounding the passengers into jelly, as would happen for a planing hull. For a model, ground effect just seems better, as long as you get enough altitude to avoid the waves. Which is why experimenting with multiple foils is probably just a waste of time.

[@SG-yq7fm]

I wonder if a swept or serrated hydrofoil would help with the ventilation issue

[@fboomerang]

You don't want a super low wing if there's any chance of chop. I live on the SF Bay and I want something to scamper from SF to the houseboat and back again. It's only about 5 nautical miles and sometimes the bay is calm, sometimes it isn't. Lots of hydrofoil options but ground effect seems to be a better overall choice - higher speeds, lower drag, likely better efficiency. I'm checking this out as it seems to solve the transport problem. Ground effect plus hovercraft means I can land on the beach or in the harbor. I'm also a Tesla Sr engineer and would want to EV convert it as a single Tesla motor is about 220kw, way more than needed for this application.

[@thesoupin8or673]

Cool vid as always! I'd love to see another long-distance autonomous project, either boat, plane, or maybe revisit the rover? Those were really interesting, but I understand they take a lot of time to make

[@nikolatasev4948]

About the Regent Seaglider - their prototype also has wingtip pontoons whose holders (not sure of the technical term) prevent the air from escaping sideways and thus increase efficiency. For added bonus, I suppose they act like winglets and help in airplane mode as well. Not sure why they don't have them in the final design. Plus, as mentioned - high wingspan helps keep efficiency even if the wing absolute height is... well higher. Which, in turn, helps operate in rougher weather. Reverse delta ground effect vehicles can also get away with higher wings (at least their leading edge). Also not sure why we don't get more of these.

[@TrogdorBurnin8or]

I think there might be a way past this with the full-size. Why does it cavitate? It cavitates because you're changing the direction of the water with the foil in order to achieve lift. If you were able to adjust the angle of attack dynamically, you could adjust it to zero, which would minimize cavitation and drag and eliminate lift at high speeds, or adjust it to steep, which would allow for high lift at low speeds.

[@speedboard.]

Have you considered trying a water rudder with one or two vertical fins to provide horizontal force? You never seemed to be able to turn too sharply while in ground effect, that could give you some much sharper maneuverability.

[@Very_Grumpy_Cat]

4:30 but why do kite surf boards with hydrofols have them in the back

[@sgt-stealth9949]

Hello, I am an embedded systems and aeronautics engineering student and I think you can keep the hydrofoil in the water by increasing its surface by making it longer but also larger. u could also place the rotors behind the aircraft (like the sr71 for example) and move the hydrofoil more towoards the nose/front of the aircraft. so the thrust is coming from behind and its helps stabilisation, or even better ur can do the opposit keep the rotors in front and bring the hydrofoil more the back you should try it actually it could be interessting keep in mind that performing these two ideas might introduce the need to add a variable angle hydrofoil for way better stabilisation !

[@TDOBrandano]

Actually, the stagnation point does not remain static with changes in angle of attack. As the angle of attack increases the stagnation point moves backward from the leading edge, on the lower surface of the wing. At high AOA a small portion of airflow on the lower surface is inverted, spilling forward and up from the high pressure under the wing to the low pressure above it, and you can easily test this with smoke tests in a wind tunnel or with short tufts attached to the leading edge of the wing.

[@dak1st]

8:27, if sharp leading edges are bad at subsonic speeds, you'll only need to make a supersonic GEV with a hydrofoil.

[@hoagietime1]

I love how the insta go is white, perfect for dropping it in the snow!

[@dnomyarnostaw]

Based on my experience in sailing hull design, I wondered if making a V hydrofoil would help with the transition from air to water. A more gradual "entry". I also was listening to an AC foiler Catamaran discussion, where they noted that any vertical surface entering the water, induced air down to the foiling surfaces, and created cavitation. That diagram showed foils entering the water with Dihedral angles, :1:57 - "Surface Piercing" instead of straight down. "Fully Submerged" Those two category's at :1:57 are deceptive. ALL foils are Surface Piercing, unless you are a Submarine.

[@michaelhaack7471]

A true engineer with big field test experience. And not scared to fail, jump up again and integrate the learnings. A truely PDCA Dreamer 😂 I love your approach.

[@cliftonmassey3143]

Have you considered making a skirtless hovercraft?

[@marcofrancioni1155]

You can reduce ventilation with a delta shaped foil protruding in front of the struts, less weed and a larger planning height range. i mean just the tip outside is enough for planning by ventilation ( just when you want). Short strut, small delta at an high AoA near the leading edge

[@maartentoors]

17:40 Best Cut Ever! Why not combine the three (1- hydrofoil 2- lidar-altitude 3- ground-effect-take-off-speed) ?

[@maartentoors]

18:15 Yeah! Song! love your vids!

[@hughgrection3052]

I wonder what would happen if you ditched the foils, and instead used like 2-4 semi rigid plastic strands. Have them in a trailing arm fashion, sort of like catfish whiskers attached to the leading edge but flowing towards the rear, dragging them. They would kind of dangle when not in use. Then once they touch the water they would bend at first, but eventually add a little resistance and push back up. Some weed-eater strings would likely be perfect. They act kid of like skids. They would be snag free and you also won't get grass snagged. This would work also on land. Even when parked it would keep a small gap on land.

[@wiegraf9009]

Basically very flexible and light skis?

[@hughgrection3052]

@@wiegraf9009 yeah pretty much

[@hughgrection3052]

He should also experiment with the new hydrophobic coatings. I bet they would prevent the stickiness of the water. They have new toroidal designs of propellers that are said to be twice as quiet and twice as efficient of conventional blades. I wonder if it will work with hydrofoils as well.

[@wiegraf9009]

@@hughgrection3052 Using a toroidal propeller with a GEV is actually a pretty promising idea, just wonder if it would get clogged with plant matter

[@hughgrection3052]

@wiegraf9009 maybe if on the foil yes. I wonder how long it will take for new super quiet subs to see and make use of the new toroidal designs. With near zero cavitation that's seen so far I bet they would benefit the most. Won't be long and I think we'll be seeing them on nearly all devices and machines, even cooling fans. I've seen how they even make outboard boats tons quite while going much faster too. It may even save some manatees and fat-chicks some motor scars in the future lol😂

[@ViiKing_]

And as a follow up project, can we get a ground effect vehicle with the propellers in the water?

[@AV1461]

8:26 The explanation for avoiding sharp leading edges seems to be valid in air. But what about in water? Water is incompressible. How does that affect the stagnation region?

[@robinbennett5994]

Air is also considered incompressible when you do subsonic aerodynamics. The changes due to transonic flow are often referred to as 'compressibility effects'.

[@DefianceFinance]

I LOVE THE OUTRO MUSIC!!!! SO WELL DONE!

[@nestofdragons]

Kavin, what if you can make the hydrofoil appear and disappear? Kind of coming out of the side-floats. Reason: just make the floats lift a bit out of the water, just to reduce drag of the hull. Once it is a bit higher, flip the hydrofoil back in and ... lets hope the decreased drag (floats higher and hydrofoil gone) will let the speed build up for take off. No need to flip them out for landings.

[@jtxtee]

Loved the bo cover at the end too. Thanks!

[@robert566]

You should do some testing with propulsion mounted in the hydrofoils. Propellers are much more efficient in water.

[@gilbertcabasse6168]

@rctestflight : Maybe the submerged part could be used as an automatic pitch control if its design was different: I imagine a boom protruding 30 cm at the front, on the central axis, an a curved ski (like a comma) attached to the end. It could be a thin (5mm wide?) carbon strip, like the one we use to reinforce wings etc, which elasticity will provide the curved shape under the stress, and a dampening of the waves. Maybe you will have to overlay several strips like a leaf spring to have a more rigid front. Then tune the angle of the entry in water so it maintains the plane pitch close to the stall angle...

[@JoeMalovich]

can you fly a brick with enough thrust? (brick shaped foam box)

[@dvlofaustin]

@rctestflight - Could you try moving the Surface Piercing blades to the outside? Seems like your setup down the middle is creating more drag?

[@kaiperdaens7670]

The song at the end😂

[@latemanparodius5133]

Given the high drag, would sweeping the hydrofoil wings be beneficial? There would be more material, but the angle might make it shear through the water better. I'm reminded of the transition between subsonic and supersonic flight, and also of the machining principle of an angled cutting tool shearing material better than a tool that is flat on.

[@scottcates]

I love, love, love the hydrofoil. Tweaking the placement is great. Since water is 800x denser than air, would it make sense to make the foil 800x smaller than the wing for a comparable lifting force?

[@Kael87full]

Look into Moth (Ship class) they use submerge foil and a analog simple system to adjuste the foils at the depht needed

[@SolarWebsite]

Established Titles is on a marketing spending spree like you wouldn't believe. For the last two weeks or so I can't watch a YT video without them popping up.

[@Blackburn6969]

You know its technically illegal to sell titles in the UK. I see this time and time again of companies using US KZbinrs to advertise this. There has been many instances of people "flaunting" or attempting to advertise their Lord or Lady title they have bought and being arrested. YOU GAIN NO UK HONOURS FROM THIS. The company that sell these small plots of land just has "permission" (which is dodgy as it is, as they could literally just make it up that you are buying a piece of land) from a land owner who has ACTUALLY been properly given the Lord or Lady title. In ANCIENT English law, if any land owned by any such title holder was sold to anyone else, than that person would also adopt the title themselves. However, this is not real today as no in those olden times, sold a singular sqft piece of land. It was a waste of time and land was precious. Lord or Lady titles may only be used when anointed by a member of the royal family, Duke(Duchess) or Baron(Baroness) in today's law. The ONLY way to gain any title properly in Scotland is to buy a Scottish Feudal Barony. They can start at $100k, with recent ones auctioning off for over $2m... Claiming a title such as Lord or Lady can be tried and prosecuted in court. This is known as "Cash for Honours" which you can look up if you wish.

[@SolarWebsite]

@@Blackburn6969 I didn't know it was illegal, I'd figure out it's pretty much fake. Like buying a square meter of moon surface.

[@The1andOnlyDrewbie]

Make it so the Foil retracts and maybe a second in the rear for take off, then fold up?

[@maeldorne5522]

At 2:11 you mention that water is more dense and so it's harder to move through it, isn't it because of the viscosity?

[@waywardscythe3358]

The regent aircraft also has WAY too narrow wings for a pure ground effect vehicle. you want to maximize you chord length in ground effect. Although with their wingspan they will be in ground effect from 0 -~35 ft above the water, so it may be more accurate to describe it as an airplane optimized for ground effect than a ground effect vehicle.

[@KenzanTsutakawaChinn]

I feel like the point of ground effects is to carry a high amount of weight for a lower amount of thrust. Can you pile a bunch of "cargo" on the vehicle?

[@mikeconnery4652]

Just a thought on turning a ground effect vehicle. Since your essentially flying flat, your tail section should steer like a car linkage. And, the front wing on the inside of the corner should create a small amount of non lift creating drag. Kind of like breaking one wheel on a car to make a tighter turn, but just slightly. Anyway, that was a fantastic lesson.

[@Ithirahad]

Would it be possible to add some sweep angle to the hydrofoil? Should get rid of the weeds, at least...

[@rekwm4747]

i dont know if you will see this but have you thought about putting the hydro foil on the back end so it trails behind the craft and anchors it to the water so to speak meaning that the craft has more stability in some turns ? ...

[@johnmarkgatti3324]

Great take on an interesting area of developemnet , The Americans spent a lot of time on foils on seaplanes ,in the 1940s ,not a lot came of it ,I now see why maybe . An Aussie guy has gone water ski waywith his boats, 'sea ski', may be the best solution for a lighter 'water form' for amphibian and sea planes . Of course modern materials can make lighter stronger hulls too .

[@kenreynolds1000]

you need a foil pitch control system. I recall a float on a pivot driving altitude for a small hydofoil back in the 80s. maybe you can use the same thing you used for the WIG and do it electronically?

[@propabilityfpv]

Cool project as always dude! I want one of those Ender printers, they look awesome. Also, Daniel deserves way more subscribers. The man made an entire parody album to go along with his channel. That's next level effort and deserves more attention!

[@JacquesTreehorn]

Good work on finding the camera. I lost a GoPro 10 at 35' depth. Found it a day after I lost it with a fresh tank, There is not a good GoPro mount available to anchor one for static underwater video. I have been filling goosenecks with lead pearl weights. Works OK.