射流泵全特性工况的数值分析及试验研究

Numerical analysis and experiment of jet-pump in conditions of complete characteristic

为了解射流泵在全特性工况下的性能和内部流场特性,采用数值分析和试验的方法对其进行研究.结果显示:在全特性工况范围内,射流泵数值模型的扩散管出口静压与流量比之间近似呈负线性关系,基于Realizable k-ε湍流模型预测的射流泵量纲一化性能曲线与试验结果基本一致,压力比和流量比之间也近似呈负线性关系;在正压正流状态下,数值分析与试验结果之间的压力比相对误差随着流量比的增大而增大,相对误差最大值约为0.26;在正压反流状态下,相对误差较小且较为稳定,最小值约为0.02;在最高效率工况附近,射流泵吸入室内部流场的速度矢量分布比较均匀,随着流量比减小,吸入室内流场会出现较为明显的局部涡旋;射流泵喉管进口截面的轴向流速分布不均匀度最大,喉管中间截面及其后续流动空间的轴向流速分布则较为均匀,在正压正流状态下,喉管内的流体混合过程主要发生在喉管中间截面之前的流动空间.

To investigate the performance and inner flow pattern of jet-pump in conditions of complete characteristic, this paper presents an experimental and numerical research on jet-pump. The results re- veal that the outlet static pressure of numerical model has a nearly negative linear relationship with the flow ratio, the numerical simulation method based on Realizable k - e turbulent model predicted the non-dimensional performance precisely compared with the experimental data, and the pressure ratio al- so has a nearly negative linear relationship with the flow ratio. Under the positive pressure ratio and flow ratio status, the relative errors between numerical model and experiment increase with the growth of flow ratio, the maximum error is about 0.26 ; under the positive pressure ratio and negative flow ratio status, the relative errors are small and stable, the minimum error is about 0. 02. Around the best effi-ciency work condition, the velocity vector distributions of suction chamber are relatively uniform, the local vortex appears in suction chamber obviously when the flow ratio decreased. The numerical results reveal that the axial velocity uniformities of the throat chamber inlet section are obviously higher than those of other sections afterwards, the axial velocity uniformities of the middle section and afterwards in throat chamber are relatively even, and the momentum exchange process is almost complete before the middle section in the throat chamber.