For monoplane of Clark Y wing, 36-feet by 6-feet, with 3.8 sq ft. equivalent flat plate area, what should be the airspeed for minimum Horsepower when fuel has been burned so that the total weight is 1800 lb?
Wing Area = 36 x 6 = 216
Weight = Lift
Weight = Max. Coefficient of lift × (density at sea level/2) × wing area × (Minimum Airspeed)^2
○ Gasoline consumption
HPreq/V = W/375 × (((Coefficient of Drag) + (1.28Ae/ wing area))/Coeffcient of Lift)
The Attempt at a Solution
Clark Y wing
Wing span = 36; wing chord = 6
Wing area = 216
Ae = 3.8 sq. ft
W = 1800 lbs
From the formula
W = Max. Coefficient of Lift × (density at sslc/2) × (Wing area) × (Minimum Airspeed)^2
Since, the problem stated that the wing is Clark Wing, Max. Coefficient of Lift of the airfoil selection is 1.56.
By substituting the given data,
Minimum Airspeed = 67.03 ft/s
My question is, does my answer correct? What is the relevant of the equivalent flat plate area on the problem?