Large eddy simulation of acoustic waves generated from a hot supersonic jet
Large eddy simulation of acoustic waves generated from a hot supersonic jet
复制标题
热超音速射流产生的声波的大涡模拟
DOI：
10.1007/s00193-019-00895-2
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发表时间：
2019
期刊：
影响因子：
2.2
通讯作者：
H. NakanoY. OzawaD. TerakadoM. YamamotoK. FujiiA. Oyama
中科院分区：
文献类型：
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作者：
T. Nonomura;H. NakanoY. OzawaD. TerakadoM. YamamotoK. FujiiA. Oyama
使用基于高保真计算代码的大涡模拟 (LES) 研究射流温度对超音速射流产生的声波的影响。六阶紧致格式和四阶龙格-库塔格式分别用于空间导数和时间积分。首先，通过模拟喷气马赫数为2.0、雷诺数为的冷超音速喷气机进行了验证和验证研究，并评估了网格分辨率和扰动强度的影响。验证和确认研究表明，网格点足以定性讨论声波产生现象，并且添加扰动对于抑制喷嘴出口处湍流转变引起的声波非常重要，如先前对亚音速射流的研究所示。然后，在腔室与大气温度之比为1.0、2.7和4.0的三种温度情况下，对射流马赫数为2.0、雷诺数为2.0的超音速射流进行LES。目前的结果表明，不同的射流温度不会改变剪切层厚度，但随着射流温度的升高，剪切层在射流内部发展得更多，导致热射流的潜在核心更短。就声场而言，随着射流温度的升高，从更宽的源区域以更宽的辐射角发出更强的马赫波。我们在热喷射情况下观察到不同角度的多个马赫波。
The effects of jet temperature on acoustic waves generated by a supersonic jet are investigated using large eddy simulation (LES) based on a high-fidelity computational code. The sixth-order compact scheme and the fourth-order Runge–Kutta scheme are employed for spatial derivatives and time integration, respectively. First, a verification and validation study is conducted using simulations of a cold supersonic jet with a jet Mach number of 2.0 and Reynolds number of, and the effects of grid resolution and disturbance strength are evaluated. The verification and validation study shows thatgrid points are sufficient for qualitative discussion of acoustic wave generation phenomena and that the addition of disturbances is important for suppressing the acoustic waves caused by the turbulent transition at the nozzle exit, as seen in previous studies for a subsonic jet. Then, LESs of supersonic jets with a jet Mach number of 2.0 and Reynolds number ofare performed for three temperature cases where the ratios of chamber to atmospheric temperature are 1.0, 2.7, and 4.0. The present results illustrate that different jet temperatures do not change the shear layer thickness, but the shear layer develops more inside the jet as the jet temperature increases, resulting in a shorter potential core for the hot jet. With regard to the acoustic fields, as the jet temperature increases, stronger Mach waves are emitted from a wider source region at wider radiation angles. We observe multiple Mach waves with different angles in the hot jet cases.