亚声速热射流声源模型的应用（英文）

发布时间：2018-07-12 08:44

本文选题：线性抛物化稳定性方程 + 失稳波　；参考：《应用数学和力学》2016年12期

【摘要】：对亚声速转捩热射流中失稳波相关的噪声产生机制进行了研究,并与冷射流中的结果进行了对比.基于时均大涡模拟(LES)流场,通过求解线性抛物化稳定性方程(LPSE)得到了失稳波的空间演化特性,然后基于LPSE的解与声比拟方法构建了射流的线性及非线性声源模型.LPSE结果表明,加热可以提高失稳波的空间增长率,使其更早达到饱和.由线性模型分析可知,加热会提高高频模态的声压级(SPL).与冷射流相比,热射流中线性模型预测的声压级与大涡模拟结果间的差距更小,表明线性机制在热射流中作用更大.在亚声速冷射流中,非线性模型在之前的研究中已经被证明可以提高声辐射效率.在当前热射流中,发现非线性模型与大涡模拟间的声压级差距被进一步的缩小,且温度相关的声源项在声辐射中发挥更重要的作用.
[Abstract]:The mechanism of unstable wave associated with noise in a subsonic transition heat jet is studied, and the results are compared with those in a cold jet. Based on the time-averaged large eddy simulation (les) flow field, the spatial evolution characteristics of the unstable waves are obtained by solving the linear parabolic stability equation (LPSE), and then the linear and nonlinear acoustic source models of the jet are constructed based on the LPSE solution and acoustic analogy method. Heating can increase the spatial growth rate of unstable wave and make it reach saturation earlier. According to the linear model analysis, the high frequency mode sound pressure level (SPL) can be increased by heating. Compared with the cold jet, the difference between the predicted sound pressure level by the linear model and the results of the large eddy simulation is smaller, which indicates that the linear mechanism plays a more important role in the hot jet. In subsonic cold jet, the nonlinear model has been proved to improve the acoustic radiation efficiency in previous studies. In the current hot jet, it is found that the difference of sound pressure level between the nonlinear model and the large eddy simulation is further reduced, and the temperature dependent sound source term plays a more important role in acoustic radiation.
【作者单位】：中国科学技术大学近代力学系;
【基金】：Project supported by the National Natural Science Foundation of China(11232011;11402262;11621202)~~
【分类号】：O358

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