Screech frequency prediction in light of mode detection and convection speed measurements for heated jets
Screech frequency prediction in light of mode detection and convection speed measurements for heated jets
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根据加热射流的模式检测和对流速度测量来预测尖叫频率
DOI：
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发表时间：
1997
期刊：
影响因子：
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通讯作者：
K. Ahuja
中科院分区：
文献类型：
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作者：
K. Massey;K. Ahuja
利用一系列实验测量了与尖叫声相关的射流不稳定性的主振型，以提高现有圆形射流尖叫声频率预报方案的精度。对喷流不稳定对流速度的测量也被用来进一步改进尖叫声频率的预测。改进后的频率预测方案使用三个独立喷嘴的四个温度比的数据进行了验证，发现显着提高了预测频率的精度。研究发现，在一定条件下，喷流可以同时以两个不同的频率尖叫，并且每个频率都与不同的不稳定性波族相关联。结果表明，随着温度的升高，扑翼型不稳定性的主导作用逐渐减弱。
The results of a series of experiments to measure the dominant mode shapes of the jet instabilities associated with screech are used to improve the accuracy of the current screech frequency prediction scheme for circular jets. Measurements of the convection speeds of the jet instabilities were also used to further refine the screech frequency prediction. The improved frequency prediction scheme is validated using data from three separate nozzles for four temperature ratios and is found to significantly improve the accuracy of the predicted frequency. It is found that under certain conditions a jet can screech at two different frequencies simultaneously, and each of these frequencies is associated with a different family of instability waves. The results seem to indicate that the dominance of the flapping type instabilities is diminished as the temperature is increased.