基于双流体模型的喷管内泡状流数值模拟

摘要

The bubbly flows through converging-diverging nozzle were numerically studied using variable step Runge-Kutta scheme, with two-fluid model. Heat interaction between the two phases was introduced in the model. The influence of initial bubble size, initial velocity difference and temperature difference between the two phases to the flow field was investigated by comparing the simulation results.With increasing initial bubble size,the void fraction fluctuates stronger. The initial velocity difference decreases rapidly nearby the nozzle inlet and the pressure increases slightly. Heat transfer coefficient impacts the distribution of gas temperature.The gas temperature approaches to the liquid quickly with larger heat transfer coefficient, and the effect to the flow field is minor.%基于双流体模型,引入两相间的热量传递方程,采用变步长的Runge-Kutta法,对喷管内泡状流进行了数值模拟.重点分析了入口处气泡半径、两相间速度差异及温度差异对流动的影响.计算结果表明:入口气泡半径越大含气率在喷管内变化越剧烈;两相间速度差异在距入口很小范围内迅速减小,入口气相速度较高时,流场压力略有升高;两相温差变化受对流换热系数影响较大:对流换热系数越大,气相温度趋近于液相温度越迅速,初始温度差异对流场影响也越小.