NAVIER-STOKES PREDICTIONS OF THE INDIVIDUAL COMPONENTS OF THE PITCH-DAMPING SUM

An approach for predicting the two individual aerodynamic damping coef ficients that form the pitch damping coefficient sum is presented. The coefficients are obtained using prescribed or forced motions that ind ependently excite the two different angular rates that are associated with the two damping coefficients. A key feature of the approach is th at steady flowfields are produced by the selected motions. Steady flow computational fluid dynamics approaches can be applied, allowing resu lts to be obtained in a computationally efficient manner Application o f the technique is made to an axisymmetric projectile configuration, T he predicted pitch-damping coefficient sum obtained by adding the indi vidually determined coefficients is in excellent agreement with previo us predictions of the pitch-damping coefficient sum and with experimen tal data, The individual coefficients are compared with slender-body t heory, and the results show similar trends though the slender-body the ory appears to underpredict the various coefficients,