Abstract: The angle between high pressure port and middle pressure port is one of the most important structure parameters for gas wave ejector. In this study, the influence of this angle on the performance of gas wave ejector is analyzed by numerical simulation and experiment. The prediction method for the optimal angle is proposed. For any given conditions, there is an optimal angle ψopt. When the angle is greater than the optimal one, a reflected shock wave is generated and the isentropic efficiency of gas wave ejector decreases significantly; While the angle is less than the optimal one, the efficiency declines slightly for the case of lower middle pressure. However, if the middle pressure is higher than pM-extra, the pressure inside the channel after a cycle is lower than that at the middle pressure outlet. A compression wave is produced when the channel is exposed to the outlet, so the efficiency drops sharply as the port angle decreases. The calculation results agree well with the experiment data, so the model could predict the optimal angel effectively. When the temperature and pressure of the inflows are constant, the optimal angels at different middle pressure are almost the same, but increase linearly with the rotation speed. The above conclusions provide guidance for gas wave ejector design and optimization.

Key words: gas wave ejector, shock wave, port angle, numerical simulation

摘要： 端口夹角是影响气波引射器性能的重要结构参数。本文通过数值模拟和实验研究探讨了端口夹角对气波引射器性能的影响机理，并得出了装置最佳端口夹角的预测方法。气波引射器存在一个最佳的端口夹角ψopt：当端口夹角大于该值时，等熵效率明显下降；若端口夹角小于最佳值，中压压力小于极值中压压力时，等熵效率随夹角的减小稍有降低，中压压力大于极值中压压力时，等熵效率急剧下降。数值模型的计算结果与实验值相一致，本文所建数值模型可准确预测最佳端口夹角。入口气体状态恒定时，最佳端口夹角不随中压压力的变化而改变，随转速的增大而线性增大。上述结论对气波引射器的设计和性能优化具有指导意义。

关键词: 气波引射器, 激波, 端口夹角, 数值模拟