TeachMe wrote: ↑Mon Feb 15, 2021 2:25 pm
Hi PrfctChaos,
I am working on a project to build my own hydrofoils and I have set up a basic parametric CAD model to quickly interchange different foil profiles and span/chord lengths.
I want to build several foils. One for pumpfoiling and maybe riding small waves, one for lightwind wingfoiling and another one for an e-foil project. (My weight is 85kg)
So Option 1 would be:
- avg: 15 km/hr
- wing span: 950mm
- area: 2000 cm^2
- req. lift: 90kg
Option 2:
- avg speed: 25km/hr
- wing span: 950mm
- area: 1600 cm^2
- req. lift: 95kg
Option 3:
- avg speed: 25 km/hr
- wing span: 950mm
- area: not exactly sure, I guess around 1600 as well
- req. lift: 130kg
Can you help me out with your program? I would be interested to validate the results in CFD and later in a field test
Best regards
Hello TeachMe,
Okay, option 1:
Results for the 950 wingspan x 2000 cm^2 wing as requested. I do not think the short wingspan and large area is doing you any favours here. At low speed you can see that high drag of almost 6Kg, mostly due to induced drag.
This is the type of geometry that I would personally choose. 1150 wingspan x 1600 cm^2 area. You can see the initial drag is down to around 4Kg and drag at cruising speed is down to around 2.5 Kg instead of 3 Kg.
Option 2:
I would probably say the 1150x1600 wing above would be the best fit for low wind winging, to easily get flying at low speeds. Below I'm showing result for 15-35km/hr speed range, which I think are fairly reasonable speeds and may be a bit fast for low-low wind winging.
950x1600 as requested:
In this case I would also recommend a change to the area, down to 1250 cm^2 for this speed range and increasing wingspan modestly to 1050mm. You can see initial and average drag is down quite a bit.
Option 3:
Results for 950 x 1600 cm^2 as requested. I think the initial drag will make it difficult to get going in this case.
The only way to get it down is to go faster, increase wingspan or reduce weight. In this case I imagine increasing wingspan is easiest. 1150 x 1400cm^2 comes out as decent improvement, but I would suggest even bigger wingspan for that type of weight and low speed would be even better for keeping cruising for longer. Unless you have plans for some high thrust motors.
Happy to revise any of these if you want to update the inputs, such as speed range etc. Would be keen to see your design / build results as well. There might be a lot, so maybe start a dedicated build thread, would be interesting. Cheers.