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