Hello
I am a beginner foiler, bought a used Liquid Force Foil Fish and now I have the itch. I have seen many high-end foils at the beach, and rode one one day, and loved the speed of it. But instead of building everything, I thought I'd build initially the wing and stab for my existing mast/fuselage and see how it goes.
As background, I am not an engineer. I live in the SF Bay Area and ride in between 12-20 knots usually. Been kiting for ~4 years.
I bought a software for foil design, and came up with the following wing:
- front wing area ~ 660 cm2 (root chord 12.5cm, tip chord 7 cm, span 66.5 cm)
- stab area ~ 180 cm2 @ -3 degrees
- foil profile Eppler 817
- Anhedral 5 degrees for front wing
- small vertical front wing tips
Assuming salt water at 60F as the flow field, I get a total lift of 411 lbs at 5 m/s (sorry the mixture of metric and English units, but this is what the software gives me). The system is stable at a trim angle of 3.08. Lift coefficient 0.388, drag coeff 0.0167, lift/drag ratio 23.16
So assuming (that's a huge assumption) that this system works, it's time to build it. My plan here is the following
- Design using a CAD program. I use Fusion 360.
- 3D print the wing in sections (slightly scaled down to compensate for next step). I designed "rods" to connect the parts just to make it stable when applying carbon.
- Lay carbon fiber (maybe with Kevlar) over it using vacuum bagging technique
- Ride
I have so many questions I don't even know where to start, but here it goes
1) Does the design seem rideable? Obviously I will need to adjust the read stab angle, but does anything here raise red flags?
2) Do I need this much front wing area? I'd rather have it smaller (shorter chord). In the simulation, at 10 m/s (~20 knots) it generates 1650 lbs of lift.
2) Does the building part make sense? I have a reasonably equipped workshop, but I opted to use 3D printing to make this faster and less expensive.
See below for the design. I am now printing the first full size wing to see how it looks, and ordered all the vacuum bagging parts/supplies.
Thanks so much for your contributions, I am learning a lot by just reading your posts.
Leo