Wing profile info for backyard hydrofoil builders

[PrfctChaos]

Hi there,

I'm looking to make a foil to learn on while being towed behind a tender. I think this realistically won't be able to go much faster than 6-7kts with the outboard it has + drag etc. Ideally the wingspan will be less than 1m as this is the width of the glass fibre I have to make glassing easy. I guess really 950mm would be best. Are you able to help me out with a wing profile? For such a low speed? I'm about 70kg + maybe 15kg of kit

Many thanks in advance.

No worries. The optimiser 5000 says that for a speed range of 10-25 km/hr, 85Kg. The best wing area is around 1700 cm^2 and best profile sd2030. Results below.

[tweoistom]

Hi there,

I'm looking to make a foil to learn on while being towed behind a tender. I think this realistically won't be able to go much faster than 6-7kts with the outboard it has + drag etc. Ideally the wingspan will be less than 1m as this is the width of the glass fibre I have to make glassing easy. I guess really 950mm would be best. Are you able to help me out with a wing profile? For such a low speed? I'm about 70kg + maybe 15kg of kit

Many thanks in advance.

No worries. The optimiser 5000 says that for a speed range of 10-25 km/hr, 85Kg. The best wing area is around 1700 cm^2 and best profile sd2030. Results below.

Capture.PNG

Nice one thanks PrfctChaos.

[salvatoreone]

I've stumbled upon this video on YT today. He made a single layer carbon part out of 3D printed mould, it's not exactly the same for our wings BUT around 4.30 min mark he achieved very nice surface finish on the print I think this could be used as a mould straight away (without making the silicone mould that he made later). I'm pretty sure the wing would be ready to go without any finishing required (other than cutting off excess), and possibly the mould would be reusable if you ever crashed your wing.

[nemoz]

I'm going to build 2 monowings the yellow ones in the pictures are the outlines the others were just reference ideas, one for medium light wind, the other for stronger wing, I'm 64kg plus probably 10 with the board wetsuit and wing so we can think about 75Kg. I don't know if you system can suggest a profile even for similar shape, can you please suggest me which profile i have to use? the small one is 65cm wide and has an area of 1100 sq cm and the bigger one is 80 cm wide and has an area of 1700 sq cm. I think the big one can have a maximum speed of 25-30 kmh the other one i have no clue...

thanking you in advance

[mandiw]

very interesting. i am working on a similar project for wingfoiling. are those mono wings intended for wing- or kite foil use? do you have already decided the exact mast position on the bigger wing (center line mast to front edge of wing)?

[nemoz]

Tecnically yes they are intended for wingfoiling. I have no idea about the exact mast position, as soon as i will have the suggestion from PrfctChaos I will start designing them, I will copy a lot from that prototype http://www.straplesskitesurfing.com/201 ... tesurfing/

[PrfctChaos]

A good video by foilingNY explaining some of the fundamental calculations.

[PrfctChaos]

I'm going to build 2 monowings the yellow ones in the pictures are the outlines the others were just reference ideas, one for medium light wind, the other for stronger wing, I'm 64kg plus probably 10 with the board wetsuit and wing so we can think about 75Kg. I don't know if you system can suggest a profile even for similar shape, can you please suggest me which profile i have to use? the small one is 65cm wide and has an area of 1100 sq cm and the bigger one is 80 cm wide and has an area of 1700 sq cm. I think the big one can have a maximum speed of 25-30 kmh the other one i have no clue...

thanking you in advance

No worries. Please see results for the 1100 and 1700 wings below. Best profiles being MH23 and S2055 respectively.

1100 cm^2:

1700 cm^2

For the larger slower wing it would be VERY advantageous to increase the wingspan, so showing results below for a 1050 mm wingspan version of the 1700 cm^2 wing as well. Best profile is still the S2055.

1700 cm^2, with 1050 mm wingspan:

[TeachMe]

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

[PrfctChaos]

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.