Assessment of hybrid RANS/LES models for the flow prediction of a supersonic ramp-cavity

Abstract Numerical flow simulations of a supersonic reattaching shear layer over a ramp-cavity are conducted using RANS and two hybrid RANS/LES turbulence models. The hybrid models are based on the detached eddy simulation (DES) framework, the SST- I D D E S model and a new proposed model called the TNT- I s D D E S model. The effects of various numerical aspects and model parameters are investigated. Advanced sub-grid length scales, known as the shear layer adapted (SLA) length and the least square (LSQ) length, are examined and compared to the traditional cubic root sub-grid length scale. An unequivocal advantage of these advanced sub-grid length scales is demonstrated. Overall, the results show that hybrid RANS/LES models, compared to conventional RANS turbulence models, significantly improve flow predictions.