Steady and Unsteady Asymmetric Flow Regions Past an Axisymmetric Body

Abstract

The theoretical solution of the flowfield past an axisymmetric body flying at a high angle of attack at subsonic flow conditions is a challenging problem since it entails large areas of boundary-layer separation and a complex vortex sheet structure. At high angles of attack, the flow is asymmetric and shows a dependence on the orientation angle, provided the body surface has sufficient roughness. Regarding theoretical simulations based on the unsteady Reynolds-averaged Navier–Stokes equations, eddy-viscosity turbulence models fail to simulate the unsteady flow structure in the rear zone of the body, yielding sectional side forces far different from those measured in experiments. Solutions obtained in this work by using Reynolds stress turbulence models combined with scale-adaptive simulation past an ogive-cylinder configuration show their ability to reproduce the essential features of the unsteady flow in the rear body. The model appears to be a suitable tool to investigate the complexities of this type of flow.