THE INFLUENCE OF VISCOUS STRESS FLUCTUATIONS IN A FLOW ON AERODYNAMICNOISE

Authors
Citation
Av. Smolyakov, THE INFLUENCE OF VISCOUS STRESS FLUCTUATIONS IN A FLOW ON AERODYNAMICNOISE, Acustica, 80(6), 1994, pp. 541-546
Citations number
13
Categorie Soggetti
Acoustics
Journal title
ISSN journal
00017884
Volume
80
Issue
6
Year of publication
1994
Pages
541 - 546
Database
ISI
SICI code
0001-7884(1994)80:6<541:TIOVSF>2.0.ZU;2-5
Abstract
The role of viscous stress fluctuations in a flow in the process of th e generation of aerodynamical (hydrodynamical) noise is considered. Ne w forms of Lighthill's equation and Curle's integral are derived. On t his basis the conclusion is made that sources of sound due to viscosit y are proportional to the divergence of a velocity field and this fact causes the viscous sources to be ineffective at low Mach number. Furt hermore, it is shown by simple example that the ''viscous sources of s ound'' in Curle's integral are false, and they arise because the visco us terms are mistakenly placed on the right-hand side of the initial w ave equation.