喷流气动噪声仿真计算  

Simulation of Separated Exhaust Jet Noise

作　　者：刘兴强[1] 黄文超[1] 李红丽[1] LIU Xing-qiang;HUANG Wen-chao;LI Hong-li(AVIC Aircraft Strength Research Institute,Xi'an 710065,China)

机构地区：[1]中国飞机强度研究所

出　　处：《科学技术与工程》2019年第22期338-342,共5页Science Technology and Engineering

基　　金：航空科学基金(2014ZD23009)资助

摘　　要：针对内外涵分开双喷流的噪声问题进行了仿真计算研究.计算采用"CFD+CAA"的混合方法,流场计算采用大涡模拟(LES),捕捉流场中的主要噪声源;声场计算采用FW-H(Ffowcs Williams&Hawkings equation)方程积分得到远场噪声信息.为了降低喷流噪声,在内涵安装了锯齿形喷嘴.安装锯齿形喷嘴后,内外涵气流掺混增强,增加了内涵的喷流有效面积,使得中低频噪声降低,高频噪声略有增加,总体降噪量3~5 dB.喷流噪声具有明显的指向性,喷流下游噪声明显高于上游,总体指向喷流下游.Simulation was launched to study the noise characterristics of esparated exhaust jet.The accurate transitent flow that contains all the information of noise source was gotten by using large eddy simulation(LES).Basing on the results of flow caculation,acoustic field was obtained by solving the Ffwocs Williams&Hawking(FW-H)equation.Chevrons nozzle was installed on the core duct to reduce the jet noise.This induced core and fan flow mixed rapidly and increases the aera of the core flow cross-section.Basing on this mixer,the mid and low frequency noise attenuted,high-frequency has a modest growth.And the total sound pressure level has a 3~5 dB reduction.The directivity of jet noise is obvious,the downstream noise is intenser than upstream.

关 键 词：喷流噪声 锯齿形喷嘴 气动噪声计算 大涡模拟 FW-H方程 

分 类 号：V211[航空宇航科学与技术—航空宇航推进理论与工程]