摘要
管道消声器的性能会因内部气流产生的二次噪声而削弱。利用简单扩张腔消声器入口和出口有无过渡圆弧2种构型,基于雷诺平均(RANS)和大涡模拟(LES)的方法,研究管道消声器的二次噪声特性。首先,通过声学分析对这2种消声器的传递损失进行对比研究;然后,基于CFD流场分析,获得消声器腔内气流的湍流强度与压力脉动分布;最后,根据流场分析结果计算获得腔内宽频噪声与近场噪声强度。研究结果显示,消声器的二次噪声特性较大程度地依赖于其几何构型,其中进出口的过渡圆弧虽然对消声器的传递损失影响较小,但却显著减小了腔内流场的剪切层速度梯度和湍流强度,从而较大程度地减弱了以宽频噪声为主的气流二次噪声强度。
The performance of the duct muffler can be reduced due to the secondary noise of the inner flow. Using two structures of simple expanded mufflers with and without transitional arc, the characteristics of secondary noise for the duct muffler are investigated based on RANS and LES. Firstly, the comparison study for the two mufflers is conducted by the acoustic analysis; then, the distributions of turbulent strength and fluctuation of pressure of the inner flow are investigated by CFD analysis; finally, the broadband noise and local noise strength are computed based on fluid analysis results. Investigation results show, the characteristics of the secondary noise for a duct muffler are largely dependent on the geometry of the muffler. The effects of the transitional arc on the performance of transmission loss for the muffler are little, while it can decrease to a great degree the gradient of the speed of shear layer and the strength of the turbulence for the inner flow, and further to reduce strength of the secondary noise dominated by broadband noise for the flow.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2017年第6期998-1004,共7页
Journal of Northwestern Polytechnical University
基金
航空科学基金(20161553014)资助
