流动环境中热水负浮力射流的近区特性分析

Analysis of near-field behavior of heated water jets with negative buoyant in flowing ambient

在对流动环境中平面热水负浮力射流进行数值模拟的基础上就近区特性进行分析,得到了不同排放角度和射流比下涡心和分离点位置等特征量的值.分析了水面上流速、温度、湍动能及其耗散率变化规律,对涡心断面上的动量方程和湍动能平衡进行了研究.计算结果分析发现回流区内湍动能最大值存在滞后的现象,浮力作用对时均量的影响较大,而对紊动量的影响则比较小.

The RNG method-based k-ε turbulence model and the hybrid finite analytic method with staggered grids were applied to simulate heated water planar negative buoyant jets in flowing ambient. The position of the eddy center and separating point in different jet angles and jet ratios were obtained by simulation. The variation of velocity, temperature, turbulent kinetic energy and its dissipation on the surface of the flow were analyzed. The balance of the momentum and turbulent kinetic energy equations along the eddy center section were illustrated. The results showed that the maximum of the turbulent energy in the recirculation region existed hysteresis, and the buoyancy affected the time averaged variables but had little effect on the turbulent ones.