The equation for the intrinsic moment of momentum averaged over small volumes of linear dimension delta has been considered. A representation of it is given as an infinite sequence of independent equations using a series expansion in terms of delta(2). The equations of different orders are obtained through linear antisymmetric operators-with a structure that is similar to that of the curl-acting on the momentum equation. The first-order term of the sequence is the Helmholtz equation; the remaining terms can be considered as balances for a kind of higher-orders vorticity. It has been shown that the coupling between the momentum and the angular momentum equation, based on a supposed antisymmetrical part of the stress tensor-which has sometimes been assumed by authors who deal with turbulent flow of a homogeneous fluid-is devoid of physical rationale. A different form of coupling is proposed that may be used to describe a turbulent flow of a homogeneous medium, using a large eddy simulation technique. In the authors model the coupling is given by a functional dependence of the turbulent eddy diffusivity over the angular momentum of a finite volume of a fluid.
|Titolo:||The angular momentum equation for a finite element of fluid: a new representation and application to turbulent modeling|
|Data di pubblicazione:||2002|
|Digital Object Identifier (DOI):||10.1063/1.1485765|
|Appare nelle tipologie:||1.1 Articolo in rivista|