Scaling of energy spectra in weakly compressible turbulence  

作　　者：Yufeng Dong Guowei He 

机构地区：[1]The State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences [2]School of Engineering Sciences, University of Chinese Academy of Sciences

出　　处：《Acta Mechanica Sinica》2017年第3期500-507,共8页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grants 11302238, 11232011, 11572331, and 11490551);the support from the Strategic Priority Research Program (Grant XDB22040104);the Key Research Program of Frontier Sciences of Chinese Academy of Sciences and the National Basic Research Program of China (973 Program) (Grant 2013CB834100: Nonlinear science)

摘　　要：We find an asymptotic expression for the characteristic timescales of decorrelation processes in weakly compressible and isothermal turbulence. This result is used in the Eddy-Damped Quasi-Normal Markovian equation to derive the scalings of compressible energy spectra: (1) if the acoustic waves are dominant, the compressible energy spectra exhibit \(-7/3\) scaling; (2) if local eddy straining is dominant, the compressible energy spectra are scaled as \(-3\). Meanwhile, the energy spectra of incompressible components display the same scaling of \(-5/3\) as those in incompressible turbulence. The direct numerical simulations of weakly compressible turbulence are used to examine the scaling.We find an asymptotic expression for the characteristic timescales of decorrelation processes in weakly compressible and isothermal turbulence. This result is used in the Eddy-Damped Quasi-Normal Markovian equation to derive the scalings of compressible energy spectra: (1) if the acoustic waves are dominant, the compressible energy spectra exhibit \(-7/3\) scaling; (2) if local eddy straining is dominant, the compressible energy spectra are scaled as \(-3\). Meanwhile, the energy spectra of incompressible components display the same scaling of \(-5/3\) as those in incompressible turbulence. The direct numerical simulations of weakly compressible turbulence are used to examine the scaling.

关 键 词：Compressible turbulence Energy spectra Two-point closure Space-time correlation 

分 类 号：O357.5[理学—流体力学]