Consider a 2D airfoil with a zero lift angle of attack of −4 degrees. The stall angle for this airfoil is 15 degrees, where the maximum 2D lift coefficient is found to be 2.0. This airfoil is used in an aircraft with a non-elliptic wing of span 20m and planform area of 60 m2 . If 1 = 2 = 0.01, the weight of the plane is 105 Newton, density of air is 1 kg/m3 , find out the maximum landing speed that the plane can have

Explanation:

Recquired Data

lift coefficient = 2.0

Distance = 20m

Area = 60m²

Force = 105 N

Density = 1kg/m³

we are recquired to find Maximum panding speed

The lift coefficient CL is defined by

CL≡L/qs=L/1/2рμ²S = 2L/рμ²S

where L, is the lift force, S, is the relevant surface area and q, is the fluid dynamic pressure, in turn linked to the fluid density rho ,, and to the flow speed u,

substituting the figure respectively

2.0 = 2 X 105 / 1 X μ² X 60

μ² = 2L /CL X P X S

μ² = 2 X 150 / 2.0 X 1 X 60

μ² = 300 / 120

μ² = 2.5

μ =1.58ms⁻²

1

explanation: