Three dimensional CFD investigation of shock train structure in a supersonic nozzle

In the present work, the shock train structure in a convergent-divergent nozzle is investigated using large eddy simulation (LES) methodology based on different subgrid models, including Smagorinsky-Lilly, Wall-Adapting Local Eddy-Viscosity (WALE) and Algebraic Wall-Modeled LES (WMLES). Therefore, the focus of the present study is to assess various subgrid models in order to predict the location of normal and oblique shocks as well as an extensive numerical study of a shock train system. In this context, dynamic grid adaption techniques and the hybrid initialization in the Fluent software are applied under the three dimensional investigation to reduce numerical errors and computational cost. The results of different subgrid models are compared with the available experimental data and it is shown that the WMLES produces more accurate results than Smagorinsky-Lilly and WALE models. Thereupon, the shock train behavior is controlled by applying the cooling wall temperature, inlet Mach number and inlet Reynolds number leading to changes in the starting point of shock, shock strength, distance between shocks, minimum pressure and the maximum flow Mach number. (C) 2015 IAA, Published by Elsevier Ltd. All rights reserved.