伴流速度对平行喷口射流影响的数值研究 |
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引用本文: | 何诚,赖焕.伴流速度对平行喷口射流影响的数值研究[J].航空动力学报,2018,33(8):2006-2015. |
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作者姓名: | 何诚 赖焕 |
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作者单位: | 华东理工大学机械与动力工程学院承压系统与安全教育部重点实验室 |
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基金项目: | 国家自然科学基金(51576067) |
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摘 要: | 采用大涡模拟方法计算研究平行喷口出口马赫数为0.9,伴流速度比分别为0.1、0.3和0.5时的喷射流场特性。计算时采用高精度的数值模拟方法,并结合Smagorinsky亚网格尺度模型。考察了流场统计平均特性、脉动特性以及射流流场中涡结构的发展演变过程,结果表明:伴流速度的增大使得势流核长度变长,减缓了空间剪切层的发展,转捩延迟。喷射流场速度分布具有自相似性,而湍流强度的分布则不具有相似性。通过分析剪切层中轴向速度脉动、径向速度脉动、压力脉动在空间任意两点上的时空相关性,发现随着伴流速度的增大,脉动量在空间上的相关性减弱,而脉动量向下游的传递速率增加。该研究结果为进一步揭示伴流速度对喷流声场的影响提供基础。
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关 键 词: | 伴流速度 射流 高精度 大涡模拟 时空相关性 |
收稿时间: | 2017/3/28 0:00:00 |
Numerical investigation of influence of co-flow velocity on plane jet |
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Abstract: | The characteristics of plane jet were investigated by large eddy simulation, at the outlet of plane jet Mach number of 0.9 and the co-flow velocity ratio of 0.1, 0.3 and 0.5, respectively. High resolution numerical method and Smagorinsky sub-grid scale model were used. The mean flow properties, fluctuations and the evolution of the vortical structures were analyzed. Result showed that with the growth of the co-flow velocity, the potential core length increased while the development of the shear layer was slowed down and the jet transition was delayed. The velocity distribution was self-similar, but possible similarity in the turbulence intensity was not found. Two-point space-time correlations of the velocity and pressure fluctuations in the shear layer were investigated. It was found that the increase of the co-flow velocity weakened the space-time correlations, but accelerated the spreads of fluctuations to the downstream. This study provides a basis for revealing the effect of co-flow velocity on the sound field. |
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Keywords: | co-flow velocity jet high resolution large eddy simulation space-time correlation |
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