SANDRAG: A Computer Code for Predicting Drag of Bodies of Revolution at Zero Angle of Attack in Incompressible Flow

摘要

A design method is presented for calculating the flow field and drag of bodies of revolution at zero angle of attack in compressible flow. The body pressure distribution, viscous shear stress, and boundary layer separation point are calculated by a combination of a potential flow method and boundary layer techniques. The potential solution is obtained by modeling the body with an axial distribution of source/sink elements whose strengths vary linearly along their length. Both the laminar and turbulent boundary layer solutions use momentum integral techniques which have been modified to account for the effects of surface roughness. An existing technique for estimating the location of transition was also modified to include surface roughness. Empirical correlations are developed to estimate the base pressure coefficient on a wide variety of geometries. Body surface pressure distributions and drag predictions are compared with experimental data for artillery projectiles, conical, and flared bodies. Very good agreement between the present method and experiment is obtained. 30 refs., 31 figs., 6 tabs. (ERA citation 10:025910)