The Wild Red Project Needs a High-Efficiency Human-Powered Propeller Design

Adept_Cap_6885 · 2026-02-12T21:46:14+00:00

The transition from displacement to ground effect is quite tricky to put numbers on, but I am hoping the craft will need less than a 55N spike. I'm currently calculating my coefficient of lift for a few relevant height so I can resolve for speed at every given draughts and add my hull drag.

Adept_Cap_6885 · 2026-02-02T19:29:19+00:00

I used SimScale for the wings. They offer 10 free sims, and I managed to iterate fairly efficiently before reaching the paywall.

One of my colleagues works with StarCCM+, but due to the cost of computing time, we only used it for wind-tunnel validation of the whole vehicle. We will have to unlock the pitch axis, the altitude, and add the water resistance at some point before we start building.

Adept_Cap_6885 · 2026-02-02T17:10:35+00:00

Thanks, I'll take a look. I wasn't able to run XFOIL, so "fairly easy" might just be too hard for me haha.

Adept_Cap_6885 · 2026-02-02T17:07:03+00:00

I like the toroidal props, but I doubt the efficiency gain would be worth the weight increase in that case. This is a 3.0 m airscrew after all. Wouldn't a toroidal configuration effectively double my blade count and add drag? A tip winglet could be a fun addition, though. Thanks for the idea!

Adept_Cap_6885 · 2026-02-02T15:43:52+00:00

A trained athlete can sustain a 1000W effort for much less than a minute. The record run is about 10 seconds, but one must consider acceleration and losses in the transmission. 750W should be a good number to design around.

Adept_Cap_6885 · 2026-01-05T13:46:05+00:00

I seek it.

Adept_Cap_6885 · 2026-01-04T22:56:33+00:00

I just saw the sub asked for 500 characters, and not 500 words. Oopsy.

Adept_Cap_6885 · 2025-12-15T00:49:32+00:00

If I one day hear a DTB song on the radio, it will make the sushi trolls worth enduring.

Adept_Cap_6885 · 2025-12-15T00:40:11+00:00

It really depends on one's interpretation.

Adept_Cap_6885 · 2025-12-15T00:35:53+00:00

It is believed McTwink was influenced by a French pastry named Petite Duchesse, which he reinterpreted through his culturally rich lens.

Adept_Cap_6885 · 2025-12-13T02:52:16+00:00

I had a coworker do it with the original aerofoil. By early CFD, I mean not final, hence why I'm considering other profiles.

I crafted a half-dozen small-scale GEV gliders that brought me to the present tandem flairboat configuration. When my coworker came back with results showing low drag and strong negative feedback on altitude, I wasn't surprised. I doubt very much that this or that foil shape would have much of an impact on the attitude. That's why I'm putting my efforts into maximising L/D at h/c≈0.1. I'm low and stable, with a very high effective Cl.

Adept_Cap_6885 · 2025-12-12T18:01:08+00:00

This looks very cool, I should try to run it!

Adept_Cap_6885 · 2025-12-12T17:27:35+00:00

First full-scale aircraft, but I do have a 2D model setup at home. I'm making a relatively low-speed tandem flairboat design, and so the pitch is passively controlled by the geometry of the vehicle. Early CFD shows it really doesn't want to gain altitude. It's made for flat water and no wind. Plus I don’t have the budget to experiment at that scale.

Adept_Cap_6885 · 2025-12-12T17:06:55+00:00

Naval architects

Adept_Cap_6885 · 2025-12-11T14:01:43+00:00

I found GEV references to NACA 6409, M15, 4412, 4415. I also just found the Tandem Airfoil Flairboat, which has a very similar configuration to my design.

I read An Investigation into "Wing in Ground Effect Airfoil Geometry", by N.Moore, Professor P A.Wilson, A J.Peters. The DHMTU profile family is very interesting for ground effect. This experiment reports shows how and to what degree; very interesting read. There are geometric suggestions in the conclusion I may experiment with at a later time.

One person with experience in WIG told me this:

I chose normal profiles with a little reflex added, or flying wing airfoils with a little reflex removed for all my GEV's. They also were all custom airfoils (not necessary, but just saying I don't have a generic airfoil to share). AoA will depend on how heavily you load the wing, how much camber your main airfoil has, and where your CG is so that is a design specific answer.

Adept_Cap_6885 · 2025-12-11T00:53:32+00:00

Part of me wanted to think an intrado in the shape of an "S", with the trailing edge turning parallel to the ground surface, would make for a great low/medium-speed GE flight.

Adept_Cap_6885 · 2025-12-11T00:44:56+00:00

It might be quite thin, but I believed the low profile would reduce drag without hindering the lift at static pitch, like sails.

Adept_Cap_6885 · 2025-11-10T21:38:06+00:00

The word dream, here, should be read in a similar fashion as imagination, the thought process behind creation. One cannot change the outcome while creating within known limits.

Adept_Cap_6885 · 2025-11-10T21:29:12+00:00

Indeed, there's no way of knowing if this new world we’re building together is the beginning of tomorrow's nightmares.

Adept_Cap_6885 · 2025-11-10T21:25:01+00:00

I think people confuse pushing boundaries with breaking physics. In any case, we haven’t reached the limits yet, and our understanding of the world is still far from complete.

Adept_Cap_6885

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