التفاصيل البيبلوغرافية
| العنوان: |
欠膨胀超声速冲击射流的大涡模拟. (Chinese) |
| العنوان البديل: |
Large Eddy Simulation of Underexpanded Supersonic Impinged Jets. (English) |
| المؤلفون: |
郑枫弋, 赖焕新 |
| المصدر: |
Journal of East China University of Science & Technology; 2022, Vol. 48 Issue 3, p388-396, 9p |
| مصطلحات موضوعية: |
LARGE eddy simulation models, THEORY of wave motion, PROPER orthogonal decomposition, FAST Fourier transforms, ACOUSTIC wave propagation, OTOACOUSTIC emissions, NOZZLES |
| الملخص (بالإنجليزية): |
In this paper, the large eddy simulation (LES) of a supersonic jet impinging on a large plate was presented. The nozzle-to-plate space was 2.08 times of nozzle exit diameter, and the nozzle-pressure ratio was equal to 4.03. Results indicated that the location and intensity of shock waves were periodical. As the Mach disc oscillates in the axial direction, the underexpanded gas had more sufficient space for expansion and thus can reach a higher speed. In the wall jet zone, the large-scale annular vortical structure was continuous. Along the radial direction, the large-scale vortices broke up and generated smaller vortices. Sound wave propagation to the upstream from the wall was observed. After reflection from the lip of the nozzle, it propagated to the downstream near the shear layer, and a feedback loop was formed. It dominated the monotone generatione. Fast Fourier transform was applied to the pressure fluctuation. The results verify that the feedback loop had the same frequency as the tone. Proper orthogonal decomposition was employed to analyze the velocity fluctuation. The modes and their energy contribution rates were calculated. The jet boundary, Mach disc and the oblique shock wave, the recirculation area and the wall jet all had strong correlation. The generation and evolution of large scale turbulence structures in turbulent field were presented and analyzed [ABSTRACT FROM AUTHOR] |
| Abstract (Chinese): |
使用大涡模拟方法对喷管总压与环境压力之比为 、喷管高度与喷口直径之比为 的欠膨胀冲击射流进行研究，并考察流场的特性与波系的结构。数值结果清晰地表明了激 波的位置与结构的周期性以及在冲击壁面与喷管唇部之间存在的反馈环。对脉动压力进行快速 傅里叶变换的结果表明，反馈环与冲击单音具有相同的频率。通过对脉动速度进行本征正交分 解，计算出各阶模态及其能量贡献率，并且讨论了湍流场中大尺度相干结构的产生、发展和演 化现象。 [ABSTRACT FROM AUTHOR] |
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| قاعدة البيانات: |
Complementary Index |
