Coarse Large Eddy Simulation of Non-Isothermal Flow Past a Circular Cylinder With Large Temperature Differences By Universal Multiscale Smagorinsky Model

Abstract

The results of incompressible wall turbulence have shown that the proposed universal multiscale Smagorinsky model (UMSM) has low sensitivity to grid resolution and Smagorinsky coefficient under precondition of assuring accuracy. To further investigate the low grid resolution requirement of the UMSM model for more complex turbulence, the wall-resolved large eddy simulation (WR-LES) of flow past a circular cylinder under the isothermal and non-isothermal cases at Re = 3900 were simulated by this model. In sothermal flow simulation, the results under a coarse grid resolutionshow excellent agreement with existing data. In the same computational domain, the grid number was only 47% that of Jogee et al. [41] and 20% that of Sircar et al. [45], which is less than other subgrid scale (SGS) models. Furthermore, the non-isothermal flow past a circular cylinder with large temperature differences (25K, 300K) was calculated by using the same grid resolution and SGS model. The turbulence statistics of the velocity and temperature obtained by the UMSM model illustrates that the UMSM model can accurate and robust simulate the non-isothermal case    without increasing the grid resolution in the near-wall layer.

Keywords: Large eddy simulation, Grid resolution, Non-isothermal flow, Flow past a circular cylinder