Comparison and Optimization of Turbulent Models and Simulation of Thermally Stratified Turbulent Flow

The Reynolds stress model(RSM) is optimized in the simulation of thermally stratified turbulent flow, which is improved in case of heated flows by solving additional transport equations for turbulent heat fluxes and for the variance of temperature fluctuations. In the paper, RSM is given together with the kε model with and without the buoyancy term, and first verified by simulating unheated turbulent pipe flow and then applied to two problems of thermal stratification and mixing. The computational results are also compared with experimental ones and the conclusion is drawn that this RSM is the most suitable model to simulate anisotropic turbulence in thermally stratified flows.