喷射器流场的数值模拟研究

Study on numerical simulation of ejector flow field

采用流体动力学计算软件FLUENT对大气喷射真空泵的超音速混合过程进行数值模拟.分析了进口压力、引射压力和出口压力的变化对引射流量的影响,及面积比、喉嘴距和扩压器出口直径等几何尺寸对工作性能的影响.结果表明,工作气体的变化对引射流量的影响较小,当工作压力波动时不会引起性能急剧下降,操作参数与几何参数对喷射器的波系结构影响很大.在一定的设计工况下,对应于最大引射流量存在一个最优面积比和喉嘴距.

Hydrokinetics calculating software FLUENT is adopted to make numerical simulation to supersonic mixing process of air jet vacuum pump.Injecting pressure and outlet pressure to injection volume is analyzed.The performance of vacuum pump is also investigated by changing the dimension of the mathematical model.The result shows that the change of pressure of working air has a little influence on injection volume,that properties will not decrease greatly while working pressure varies,and that operating parameters has great influence on structure of wave system of ejector.There are optimum throat area ratio and ideal nozzle position for a given operating condition.