摘要
本文介绍了冷热水汇合、盐淡水汇合及含盐冷热水汇合流动的部分试验结果,并建立了用于模拟分层流的数学模型。实验结果表明,在所研究的流动范围内,流速比(V_2/V_1)和密度弗劳德数(F_0)是影响两股流体掺混的主要因素,密度分层流稳定的临界条件可用F_0和V_2/V_1的简单关系式表示,与雷诺数R_e没有直接的关系。数值模拟结果与实验结果的比较表明,所建立的数学模型能正确地模拟温度分层流和盐度分层流。从模型的结构可知,本模型较好地反映了各向异性紊流特征及分层与紊动的相互影响等。
An experimental investigation on turbulent mixing and density stratification of flows which result from the merging of two layers of flow with temperature difference(or with salinity difference, or with both temperature difference and salinity difference) was conducted in detail, and a mathematical model for density stratified flow is suggested. In the paper, some experimental results and computational results are reported. The experimental results show that within the scope of flow investigated, major factors which influence the mixing are the velocity ratio (V_2/V_1) and density Froude number(F_0), critical condition of stratification stability can be dcscribed by a simple formula about V_2/V_2 and F_0, and it is not related to the Reynolds number(Re). The comparison between computation results and experimental results shows that the present model can be used to simulate temperature stratified flow and salinity stratified flow correctly. According to the structure of model, it can be believed that the present model reflects the feature of anisotropic turbulence and the interaction between stratification and turbulence reasonably.