CAJ | 학술논문

利用大涡模拟方法,对刚性光滑平板上充分发展的低马赫数湍流边界层流动进行了数值模拟.在此基础上将时一空变化的湍流流场信息作为近场声源,运用Lishthill的声学类比理论计算了边界层辐射噪声.文中讨论了偶极子、四极子对噪声的贡献,通过对比它们的功率谱密度,认为壁面剪切应力(偶极子)是湍流边界层辐射噪声的主要来源.
이용대와모의방법,대강성광활평판상충분발전적저마혁수단류변계층류동진행료수치모의.재차기출상장시일공변화적단류류장신식작위근장성원,운용Lishthill적성학류비이론계산료변계층복사조성.문중토론료우겁자、사겁자대조성적공헌,통과대비타문적공솔보밀도,인위벽면전절응력(우겁자)시단류변계층복사조성적주요래원.
Large Eddy Simulation (LES) was used to investigate space-time field of the low Mach number, fully developed turbulent boundary layer on a smooth, rigid fiat plate. The flowfield simu-lated by LES was taken as near-field sound sources and radiated sound from turbulent boundary layer (TBL) was studied using Lighthill's acoustics analogy. The radiated sound of dipole type, of quadrupole type, and of the sum of the two above were discussed. Comparing their power spectral densities, it is concluded that in low Mach number, the wall shear stress (dipole type of source) is the predominant factor responsible for sound radiation from TBL.