Inviscid drag at transonic speeds

Abstract

A systematic asymptotic expansion procedure is introduced into the Euler equations to obtain the transonic, small-disturbance potential equation and corresponding relation for the drag. The relation consists of an integral around any contour enclosing the body and an integral along all shocks contained within the contour. Interpretations are given for the origin of the pressure drag due to shock waves, lift, and wind-tunnel boundaries. Numerical procedures are discussed for evaluating these quantities from finite-difference relaxation calculations. Computed results are included for various contours, and results are compared with some experimental data.