文献类型：期刊文献

英文题名：Numerical Study of Turbulence and Noise in Chevrons Nozzles at the Mach Number Equal to 0.25

作者：Meng, Qingbo[1];Lai, Huanxin[1]

机构：[1]East China Univ Sci & Technol, Sch Mech & Power Engn, Shanghai, Peoples R China

年份：2021

卷号：56

期号：5

起止页码：745

外文期刊名：FLUID DYNAMICS

收录：;EI(收录号：20213910935021);WOS:【SCI-EXPANDED(收录号:WOS:000698679100013)】；

基金：This study is funded by the National Natural Science Foundation of China under Grant 51976061.

语种：英文

外文关键词：jet noise; chevron nozzle; large eddy simulation; low Mach number jet

摘要：Turbulent jet flows at the Mach number equal to 0.25 from an industrial nozzle are studied using the large eddy simulation (LES). The feasibility of controlling the jet flow and noise by using chevrons is explored. A comparative study is carried out between the baseline and chevrons nozzles with the focus paid to the influences of the chevrons on the flow mixing and noise. The results show that the chevrons can significantly change the flow field. Especially the jet potential core length is reduced. In addition, the contours of velocity in the cross sections of the jet change from circular into daisy shaped structures by the chevrons. Flow visualization using the vorticity and the Q criterion shows that large vortical structures in the shear layer are fragmented into small-scale eddies. Meanwhile, the sound pressure level of the jet noises is weakened by chevrons.