静止环境中垂直平面浮力射流稳定性与混合特性数值研究

针对不同的射流参数和环境流体参数下的有限深平面垂直射流，采用混合有限分析法对近区以稳定浮力表面层形式排放和由于近区漩涡产生二次吸附的非稳定排放两种流动形态的混合流体的流速场和温度场进行了数值模拟。结果表明近区排放稳定性主要取决于排放佛汝德数和相对淹没度，而与受纳水体的远区几何形状无关；受纳水体的远区几何形状只对排放水体的混合性质产生影响，这一点对非稳定排放尤其显著。所得结果与Jirka和Harleman的理论分析和试验结果十分吻合，说明所采用数值方法可对平面浮力射流的流动现象进行完整的预报。

Numerical study on stability and mixing characteristics of vertical plane buoyant jet in confined depth

The hybrid finite analytic method is applied to numerically study the plane turbulent jet discharged into still water with confined depth from bottom. Two flow patterns are to be considered: 1.the mixed flow in near field is flowing stably towards downstream in the form of buoyant surface layer, 2.the unstable buoyant flow discharged with recirculation and re-entrainment. On this basis the discriminant for stability of plane turbulent buoyant jet is analyzed. It is found that the stability of the discharged flow in the near field depends on the Froude number and degree of submergence, and the geometric shape of the water body in far-field will affect the mixing property of the flow. The numerical prediction is in excellent agreement with Jirka's experimental data.