On a general theory for compressing process and aeroacoustics:linear analysis

作     者：E .Mao Y. P. Shi J. Z. Wu 

作者机构：State Key Laboratory for Turbulence and Complex Systems College of Engineering Peking University 100871 Beijing China University of Tennessee Space Institute Tullahoma TN 37388 USA 

出 版 物：《Acta Mechanica Sinica》 (力学学报（英文版）)

年 卷 期：2010年第26卷第3期

页      面：355-364页

核心收录：

学科分类：080705[工学-制冷及低温工程] 07[理学] 08[工学] 0807[工学-动力工程及工程热物理] 0802[工学-机械工程] 070102[理学-计算数学] 0701[理学-数学] 0801[工学-力学（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：supported by the National Basic Research Program of China(2009CB724100) 

主　　题：Longitudinal (compressing) processTransversal (shearing) process Acoustic mode Entropy mode Aeroacoustics 

摘      要：Of the three mutually coupled fundamental processes （shearing, compressing, and thermal） in a general fluid motion, only the general formulation for the compress- ing process and a subprocess of it, the subject of aeroacous- tics, as well as their physical coupling with shearing and thermal processes, have so far not reached a consensus. This situation has caused difficulties for various in-depth complex multiprocess flow diagnosis, optimal configuration design, and flow/noise control. As the first step toward the desired formulation in fully nonlinear regime, this paper employs the operator factorization method to revisit the analytic linear theories of the fundamental processes and their decomposi- tion, especially the further splitting of compressing process into acoustic and entropy modes, developed in 1940s-1980s. The flow treated here is small disturbances of a compressible, viscous, and heat-conducting polytropic gas in an unbounded domain with arbitrary source of mass, external body force, and heat addition. Previous results are thereby revised and extended to a complete and unified theory. The theory pro- vides a necessary basis and valuable guidance for developing corresponding nonlinear theory by clarifying certain basic issues, such as the proper choice of characteristic variables of compressing process and the feature of their governing equations.