Dynamic subgrid-scale modeling for high-speed transitional boundary layers

Abstract

The subgrid scales are modeled dynamically in a large-eddy simulation of transitional boundary-layer flow along a hollow cylinder at a Mach number of 4.5. The behavior of the dynamic-model coefficients, which is determined from local information in the resolved field, is investigated through both an a priori test with direct numerical simulation data for the same case and a complete large-eddy simulation. Both contractions proposed by Germano et al. (1991) and Lilly (1992) are used for the unique determination of the coefficients of the dynamic model, and their results are compared and assessed. The behavior, as well as the energy cascade of the subgridscale field structure, is investigated at various stages of the transition process.