喷嘴调节锥对水蒸气喷射泵性能影响的数值模拟

Numerical Simulation of Influence of Nozzle Spindle Position on the Performance of Steam Ejector

喷嘴的喉部面积大小对水蒸气喷射泵性能至关重要,提出了一种可调式喷嘴结构,通过调节锥位置改变来调节喷嘴喉部面积,以此作为计算模型,数值分析了调节锥位置对喷射泵性能的影响.比较了不同调节锥位置条件下水蒸气喷射泵内部的速度场、轴线压力分布、近壁面流场迹线.结果表明,在相同的工况下,调节锥位置可以显著影响喷射泵的性能,随着喷嘴喉部面积的减少,喷射泵内部的激波位置向入口方向偏移,强度持续减弱,边界层脱离现象先减弱后增强,当调节锥位置处于喷嘴喉部后15 mm附近,喷射泵性能达到最佳值.

The throat area of the nozzle is important for the performance of the steam ejector,a variable area nozzle structure which is capable to adjust the nozzle throat area by adjusting the position of spindle is proposed and the numerical analysis toward the influence of the spindle positions on the performance of the steam ejector is also discussed.The velocity flow field,axial pressure distribution and near-wall flow field of the steam ejector under different spindle positions were compared.The results showed that under the same working condition,the spindle position can significantly affect the performance of the steam ejector.With the decreasing of nozzle throat area,the shock wave position in the jet pump was shifted to the inlet direction,and the intensity was continuously weakened.The phenomenon of boundary layer separation is weakened first and then enhanced.When the nozzle spindle position is around 15 mm,the performance of jet pump reached the best value.