Abstract:
Stability and flutter derivatives are obtained for rectangular wings describing plunging and pitching oscillations in subsonic flow. These are evaluated by applying the simple approximate 'equivalent' wing theory (R. & M. 2855) with the vortex-lattice method of downwash calculation. The derivatives for the wing of aspect ratio 4 at Mach number 0.866 are compared with values calculated by a method based on exact theory; at this high Mach number it is found that the present method is sufficiently accurate for only a very limited range of the frequency parameter. At very low values, the pitching-moment derivatives for this wing are in reasonable agreement with those calculated by the Multhopp-Garner method and with results from wind-tunnel tests at high subsonic Mach number.
