
Accession Number : ADA299639
Title : 3D Vector WaveletBased Subgrid Scale Model for LES of Nonequilibrium Turbulence.
Descriptive Note : Performance rept. 21 Feb 9420 Feb 95,
Corporate Author : HOUSTON UNIV TX
Personal Author(s) : Zimin, Valery ; Hussain, Fazle
PDF Url : ADA299639
Report Date : 11 APR 1995
Pagination or Media Count : 33
Abstract : We have laid the foundation to develop and validate LES using wavelets as a functional basis and based on subgrid scale (SGS) modeling using vector wavelets. Wavelet LES (WLES) consists of subgridscale model equations (SSM) and spaceresolved model (SRM) equations. Using a vector wavelet decomposition of the velocity field a simple model for locally isotropic turbulence has been derived from the NavierStokes equation. This model, which involves no empirical or adhoc parameter Incorporates nonlocal interscale interactions, reveals backscatter and can be applied to represent smallscale turbulence in LES schemes. Stationary solutions of the model equation & produce the Kolmogorov k(5/3) inertial spectrum and the k(4) infrared spectrum. We have completed derivation of the SRM equations based on the helical wave decomposition. We will test the SRM equations using the computational resources in this NAS operational year. A waveletbased subgridscale model (WSSM) will be generalized to account for anisotropic and inhomogeneous turbulence in wallbounded flows and will employ a nonuniform grid to resolve the nearwall structures. (AN)
Descriptors : *MATHEMATICAL MODELS, *TURBULENCE, *NONEQUILIBRIUM FLOW, VELOCITY, COMPUTERIZED SIMULATION, GRIDS, EDDIES(FLUID MECHANICS), TURBULENT BOUNDARY LAYER, ENERGY TRANSFER, BACKSCATTERING, COMPUTATIONAL FLUID DYNAMICS, THREE DIMENSIONAL, FLOW FIELDS, APPROXIMATION(MATHEMATICS), KINETIC ENERGY, NAVIER STOKES EQUATIONS, VISCOSITY, INFRARED SPECTRA, SKIN FRICTION, BOUNDARY LAYER FLOW, NONUNIFORM.
Subject Categories : Fluid Mechanics
Distribution Statement : APPROVED FOR PUBLIC RELEASE