Specific features of the aerodynamic moment and the pitch damping of a re-entry vehicle model exercising free oscillations at supersonic speeds

Abstract

A method for treating experimental data obtained on a setup with free oscillations over the pitching angle of the model and for determining the unsteady aerodynamic characteristics of the pitching moment coefficient is described. It is found that the pitching moment coefficient of a re-entry vehicle model at Mach numbers M = 2 and 2.25 and fixed angles of attack a depends non-linearly on the rate of change of the angle α. This circumstance makes the concept of aerodynamic derivatives inappropriate for mathematical description of the pitching moment coefficient.