For those designing wings here is a rough guide to compute approximate lift based on wing surface area.
Lift in Pounds = Surface Area in Square Feet * Velocity in fps * Velocity in fps * coefficient of Lift
or
L = S * (( V * V ) * C)
Where:
* = times or multiples of
L = Lift in Pounds(lbs)
S = Square Area in feet(ft)
V = Velocity in feet per second(fps)
Note: V * V is the square root of V
C = Coefficient of Lift
Note: For purposes here the coefficient of lift is equal to one(1).
To obtain a Square Area in feet of your wing go here:
http://www.airfieldmodels.com/informati ... g_area.htm
The measurement process computes one(1) side of the total wing area so remember to double the area before applying to the formula to obtain total lift.
Conversions
1 cm2 = .00107639 ft2
cm2 = square centimeters
ft2 = Square feet
Knots(kts) to fps Chart
kts fps
1 1.68781
2 3.37562
3 5.06343
4 6.75123
5 8.43904
6 10.12685
7 11.81466
8 13.50247
9 15.19028
10 16.87808
11 18.56589
12 20.2537
13 21.94151
14 23.62932
15 25.31713
Using the L = S * (( V * V ) * C) formula a 0.7 square foot wing surface area provides the following lift.
Kts Lift in lbs
1 1.99
2 7.97
3 17.94
4 31.90
5 49.85
6 71.78
7 97.71
8 127.62
9 161.52
10 199.40
11 241.28
12 287.14
13 337.00
14 390.84
15 448.67
In closing readers should remember that a hydrofoil wing/mast combination probably obtains two(2) types of lift. The lift generated by the wings and lift generated by the mast under certain conditions. For list from the mast cross reference the centerboard hydrofoil effect.
Light and Frost