【摘要】 以Navier Stokes方程和应力 通量代数湍流模型为基础,建立了温度和盐度分层流的应力 通量代数模型,模型不仅在控制方程中计及密度变化,而且在应力和通量的代数关系中含有浮力项,从而自动地计及浮力对紊动的影响.另外紊动平均量控制方程中的紊动项是由应力 通量模型计算,较好地体现了湍流各向异性的特征.为验证模型的正确性,对同时存在温度和盐度梯度的密度分层流进行了数值模拟计算,结果正确地反映了分层及紊动各向异性的特征,与实测结果吻合较好.更多还原

【Abstract】 Based on the Navier-Stokes equation and the algebraic stress-flux turbulence model, the algebraic stress-flux model for thermal and saline stratified turbulent flow in aquatic environment was established. In the control equations of the model, density variation was considered, and the algebraic relations for the stress and the flux included buoyancy terms, so the directional effects of buoyancy on turbulence were automatically accounted in the model. Because turbulent terms are calculated by algebraic stress-flux model, the non-isotropic characteristics of turbulence were reflected very well. In order to verify the model, density stratified flow with both the vertical temperature gradient and the vertical salinity gradient is simulated numerically. The features of stratification and non-isotropic turbulence are described by the model. The computational results agreed well with the experimental data.更多还原