Scale-Resolving Simulations of the Streamwise Vortex Downstream of a Delta Wing

Abstract

This paper investigates simulation strategies to accurately predict the streamwise Evolution of the longitudinal vortex that is generated at the leading edge of a delta wing. For this purpose different hybrid RANS/LES approaches are assessed by comparison with experimental reference data. As test case a new wind tunnel experiment is considered, which provides detailed data of the vortex evolution downstream of the delta-wing trailing edge using stereoscopic particle image velocimetry. Since in this work the vortex development in the wake is of primary interest, the flow around the delta wing is modeled with RANS, whereas a scale-resolving LES is only applied in its wake. This approach reduces the computational effort compared to pure LES and enables a systematic study of different grid designs and suitable positions of the RANS/LES interface. The results show the importance of applying synthetic turbulence to trigger the generation of resolved structures at the RANS/LES interface.