Page 215 - Aerodynamics for Engineering Students

198 Aerodynamics for Engineering Students

Fig. 4.21

(4.98)

and adding the free stream gives

(4.99)

Differentiating to find the velocity components

(x - x1)
dx1 (4.100)

dxl (4.101)

To obtain the tangential velocity at the surface of the aerofoil the limit as y 4 0 is
taken for Eqn (4.100) so that

(4.102)

The coefficient of pressure is then given by

(4.103)