两相湍浮力分层流k-ε模型

k ε model of turbulent buoyant stratified two phase flow

将研究精细的两相湍浮力分层流预报模型作为目标，广泛地涉及了两相湍浮力分层流精细模拟的理论和方法．以通用的ｋ－ε湍流模型为基础，考虑了浮力对紊动的影响，建立了两相湍浮力分层流的ｋ－ε模型，对存在速度和密度分层的湍浮力流动进行了数值模拟．计算结果正确地反映了分层及紊动特征。

The paper reports on the application of a k ε model of turbulent buoyant flow to the calculation of turbulent mixing layers subjected to strong stable stratification. The eddy viscosity and diffusivity coefficients are computed from the two equation k ε turbulence model. The effect of buoyancy on the turbulence can be accounted for in the model at two levels. The first level is to include the buoyancy terms in control equations. The second level is to account for the buoyancy influence by the Munk Anderson formula which leads effectively to non isotropic eddy viscosities and diffusivities as functions of the local Richardson number. The directional effect of buoyancy is automatically accounted for. The model can correctly predict recirculating flows and complex three dimensional flows in coastal waters. The present work continues the verification process by examining model's performance in strong stratification.