Numerical simulation of the effect of spatial disturbances on vortexasymmetry

Abstract

The steady asymmetric vortex pattern observed on slender bodies of revolution at large angle of attack was investigated using fine-grid Navier-Stokes computations. The computed results demonstrate the marked asymmetry which has been observed in experiments. To obtain asymmetry, it was found essential to introduce a space-fixed time-invariant perturbation into the computation. The computational results suggest that vortex asymmetry is forced by amplification of small disturbances, such as those due to surface roughness, occurring within the body viscous boundary layer.