Hybrid turbulence models for flows around a stationary smooth circular cylinder

Abstract

The aim of this paper is to evaluate the accuracy, stability and efficiency of the different hybrid turbulence models via the benchmark computations of flows around a stationary smooth circular cylinder. The hybrid turbulence models have been validated and applied a lot in turbine flow, combustion, aerodynamic and aeroacoustic problems, while not much in hydrodynamic problems. In order to verify the simulation performance of the newly proposed hybrid strategies, this paper uses the SST-PANS, SST-SAS and SST-IDDES to compare the numerical simulation of the large separation flow problem. The model performance is assessed by a detailed comparison of predictions regarding the turbulence characteristics, the hydrodynamic characteristics, and the distribution of eddy-viscosity. The self-developed CFD solver, vim-FOAM-SJTU, is used in the present simulations. From the assessment, it is confirmed that the hybrid models have the abilities to calculate the small-scale motions, and all models can be employed to predict the unsteady characteristics of wake vortices advantageously. Both the SST-PANS and SST-IDDES models can capture complex flow structures and physics mechanism. The SAS model using the Lvk scale with features of local-adaptive and grid-independent can predict the eddy-viscosity reasonable. When the constant Cs = 0.11 contained in the Lvk limiter is modified to be Cs = 0.08, SST-SAS is also able to achieve better performance in the same mesh. The hybrid model can calculate and simulate the 3D vortex structure well, which is closer to the real physical phenomenon. And SST-IDDES has the best simulation results. The numerical results from SST-IDDES show its comparable capabilities for simulation of massively separated hydrodynamic flows and its potential application in the prediction of industrial turbulent flows for vortex-induced motions (VIM).