多管反馈式流体振荡器性能研究

Performance of multi-tube feedback fluid oscillator

为研究多管反馈式流体振荡器的内部流动过程和振荡性能,采用CFD数值模拟对流动过程以及控制段长度和膨胀比对不同出口振荡性能的影响进行研究,并辅以实验验证。结果表明:振荡腔内部低压区和反馈射流共同推动射流附壁切换;增大反馈段长度或降低膨胀比都将使不同出口射流对应的振荡频率减小;反馈段长度对不同出口压力保持率影响不大,膨胀比为2时,最大差值不超过7%;膨胀比越小,出口压力保持率越大,当反馈段长度为100 mm时,最大差值可达31.57%。实验结果验证了模拟规律,但由于实验偏差导致实验数值偏低,振荡频率和压力保持率实验值比模拟值最大分别低184.64 Hz和21.19%。

To study the internal flow process and oscillation performance of a multi-tube feedback fluid oscillator,CFD was used to simulate the flow process and the effects of control section length and expansion ratio on the oscillation performance at different outlets.It was also verified by relevant experiments.The results show that the low pressure region inside the oscillating cavity and the feedback jet together drive the switch of the jet attached to the wall.Increasing the length of the feedback section,or decreasing the expansion ratio,the oscillation frequency of the different outlet jets is reduced.The length of the feedback section has little effect on the different outlet pressure retention rates,and the maximum difference does not exceed 7%for an expansion ratio of 2.The smaller the expansion ratio,the greater the outlet pressure retention.The maximum difference is up to 31.57%,when the length of the feedback section is 100 mm.The experimental results verify the simulation law,but the experimental deviations lead to low experimental data.The maximum experimental values of oscillation frequency and pressure retention rate are up to 184.64 Hz and 21.19%lower than simulation values,respectively.