Simulation of afterbody transonic flows using partially-averaged navier stokes model for turbulence

EADS ASTRIUM, Route de Verneuil 66 — BP 3200, Les Mureaux 78133, France

Abstract

This investigation is dedicated to the elaboration of a numerical strategy to simulate accurately and at a reasonable cost the main unsteady features of high Reynolds separated flows. Within this framework, the Partially-Averaged Navier Stokes (PANS) turbulence model has been used. In this hybrid approach, the modeled-to-resolved scale ratio (the level of physical resolution) is introduced and set explicitly in the closure model of the unresolved scales which is based on the ReynoldsAveraged Navier Stokes (RANS) paradigm. The flow separation behind an axisymmetric afterbody has been simulated. The large-scale coherent structures are captured and the comparison of the results with wallpressure measurements shows that the flow physics simulated is relevant. Nevertheless, these encouraging results need to be confirmed by deeper investigations on the model behavior and its sensitivity to physical as well as numerical parameters. This step of validation is mandatory before considering an extensive use of the approach at an industrial level.