The Influence of Scale Resolving Simulations in Predictions of Vortex Interaction about a Generic Missile Airframe

Abstract

Hybrid Reynolds Average Navier-Stokes (RANS) - Large Eddy Simulations (LES) have been applied to predict the rolling moment coefficient of a generic missile at high angle of incidence in supersonic flow. The missile airframe was rolled which generated unsymmetrical vortices affecting the downstream tail fin section. Traditional RANS indicated difficulties predicting the rolling moment. This challenge was accepted by the NATO Science and Technology Organization (STO), Applied Vehicle Technology (AVT) panel forming a devoted Task Group AVT-316 “Vortex Interaction Effects Relevant To Military Air Vehicle Performance”. The paper describes the Missile Facets work on scale resolving simulations with spatial and temporal resolution strategy, quality index for LES and comparison with industry standard RANS methods. The hybrid RANS-LES results provided additional insights into the nature of the complex vortex interactions, including shocks, associated with slender body aerodynamics not detected with RANS. Scale resolving simulations drastically reduced vortex dissipation and resulted in significant shift of rolling moment magnitude.