平面槽道湍流壁面脉动压力的特性与机理研究  

Characteristics and Mechanism of Fluctuating Pressure on Turbulent Wall Surface in Planar Channel Flow

作　　者：李昌龙 黄修长[1,2] 杨咏 LI Changlong;HUANG Xiuchang;YANG Yong(The State Key Laboratory of Mechanical System and Vibration,Shanghai Jiaotong University,Shanghai 200240,China;National Engineering Research Center of Special Equipment and Power System for Ship and Marine Engineering,Shanghai Marine Equipment Research Institute,Shanghai 200031,China)

机构地区：[1]上海交通大学机械系统与振动全国重点实验室,上海200240 [2]上海船舶设备研究所船舶与海洋工程特种装备和动力系统国家工程研究中心,上海200031

出　　处：《噪声与振动控制》2024年第6期16-22,共7页Noise and Vibration Control

基　　金：国家自然科学基金资助项目(51875336,12121002);上海高校特聘教授(东方学者)岗位计划;上海交通大学深蓝资助项目(SL2021MS007)。

摘　　要：以平面槽道湍流壁面脉动压力特性以及边界层速度源项对壁面脉动压力的贡献为研究关注点。基于约翰霍普金斯大学湍流数据库中的平面槽道流直接数值模拟数据,利用格林函数求解泊松方程构建边界层速度源项与壁面脉动压力的理论关系,通过傅里叶变换计算壁面脉动压力谱和边界层速度源项分压谱,揭示壁面脉动压力谱的波数-频率域的特性,对比分析边界层不同区域不同源项对壁面脉动压力的贡献。结果表明,壁面压力自功率谱在低频、中频和高频段的形状分别为ω^(2)、ω^(-0.775)和ω^(-5);波数-频率谱中迁移脊在波数130 rad/m、频率120 rad/s区域,揭示湍流涡旋结构迁移速度为0.54倍流速;壁面脉动压力主要由速度场源中平均剪切湍流作用项Pms与湍流-湍流作用项Ptt共同影响,Pms贡献占主导。The objective of this investigation is to study the characteristics of the fluctuating wall pressure and the contribution of the velocity-field source terms in the boundary layer to the fluctuating wall pressure in a planar channel flow.Based on the DNS results of the channel flow in the Johns Hopkins turbulence databases,the Green′s function was used to solve the Poisson equation to build the theoretical relationship between the velocity-field source terms in the boundary layer and the fluctuating wall pressure.The fluctuating wall pressure and the partial pressure spectrum were calculated by Fourier transform to reveal the characteristics of the fluctuating wall pressure in wavenumber-frequency domain and analyze the relative contribution of different source terms in different regions of the boundary layer to the fluctuating wall pressure.Results show that the auto-power spectrum of the fluctuating wall pressure has the shape of ω^(2) at low frequencies,ω^(-0.775) at medium frequencies and ω^(-5) at high frequencies.In the wavenumber-frequency spectrum of fluctuating wall pressure,there is a convection ridge with a high spectral level at the wavenumber of 130 rad/m and the frequency of 120 rad/s,which reveals that the convection velocity of turbulent vortex structure is about 0.54 times of the flow velocity.The wall fluctuating pressure is mainly affected by the mean shear turbulence term Pms and turbulence-turbulence term Ptt in the velocity-field source terms,and the contribution of the mean shear term is the dominant.

关 键 词：振动与波 平面槽道湍流 壁面脉动压力 特性 机理 边界层 

分 类 号：O353.1[理学—流体力学]