A Method of Calculating the Short-PeriodnLongitudinal Stability Derivatives of a Wing in Linearised Unsteady Compressible Flow

摘要

A method is developed for the calculation of the pressure distribution and the aerodynamic forces and moments on a wing performing harmonic pitching and heaving oscillations. The calculation is based on the assumption of inviscid potential flow without shock waves and is restricted to small incidence, so that the linearized theory is valid.nIn contrast to other work in the field the theory applies to all Mach numbers. It is restricted to small values of the reduced frequency and should be valid for the usual range of short periods occurring at present in flight. The formal solution yields two integral equations for the parts of the load, which are in phase and go out of phase with the oscilla-tion;these are of the same form as the corresponding equation in steady flow.