Rectangular Wings

Consider supersonic flow over a rectangular wing, Fig. 6.38.

The pressure is constant along rays from the tips of the leading edge. From symme­try of pressure in the tip region, it may be shown that the average pressure coefficient is half the two-dimensional pressure coefficient. One finds the three-dimensional lift coefficient CL from (see Ref. [11]) [6] 2

Rectangular Wings

Подпись: Fig. 6.37 Superposition of elementary solutions
Подпись: Fig. 6.38 Pressure distribution at the trailing edge (Elements of Gas Dynamics 2001 edition, by Liepmann and Roshko, with kind permission of Dover publication)

Rectangular Wings Подпись: (6.139)
Подпись: PAR
Подпись: 2 Подпись: 3
Подпись: O

Fig. 6.39 Evolution of loss of lift coefficient with Mach number

The loss of lift due to tip effect is plotted in Fig. 6.39.

Wings with subsonic edges are more complicated, due to the singularity of thin airfoil theory there.