Accession Number : ADA307116

Title :   Experimental Evaluation of Pressure-Strain Models in Complex 3-D Turbulent Flow Near a Wing/Body Junction.

Descriptive Note : Technical rept. 1 Jan 94-31 Dec 95,

Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF AEROSPACE AND OCE AN ENGINEERING

Personal Author(s) : Oelcmer, M. S. ; Simpson, R. L.

PDF Url : ADA307116

Report Date : FEB 1996

Pagination or Media Count : 158

Abstract : Comparisons of experimentally-extracted pressure/rate-of-strain values were made to theoretical pressure-strain models for several locations of a wing-body function flow. The experimental pressure/rate-of-strain results were calculated from data obtained with a LDV technique. The data consist of profiles of mean velocity and higher order moments including quadruple products in a two-dimensional turbulent boundary layer (2DTBL), a strongly skewed three-dimensional turbulent boundary layer (3DTBL) in the vicinity of a 3-D separation line; and around the center of the horse-shoe vortex that forms around the wing. Terms in the transport equations for the Reynolds' stresses and the turbulent kinetic energy are also presented here. Several linear and non-linear pressure/rate-of-strain models are tested using the measured quantities as input to the models. The tested models are the Launder-Reece-Rodi (1975), Gibson-Launder (1978), Oberlack-Feters (1993), Fu-Launder-Tselepidakis (1987) (2 models), Shih-Lumley/Choi-Lumley (1985, 1984), and Speziale-Sarkar-Gataki (1991). The measurements were carried out in the Virginia Tech Boundary Layer Tunnel, at nominal air speed of 27.5 m/s around a NACA 0020 tailed and 3:2 elliptical nosed wing shape. Near-wall correction effects on the theoretical pressure/rate-of-strain models; effect of approximation for the pressure diffusion, the anisotropic dissipation approximation as well as isotropic dissipation approximation on the experimental pressure-strain data are examined. The results are compared to previous Direct Numerical Simulation data qualitatively. Data show that the pressure-diffusion approximation by Lumley (1978) is an important term in the V2, UV, and VW stress budgets.

Descriptors :   *STRESS STRAIN RELATIONS, *TURBULENT FLOW, *THREE DIMENSIONAL FLOW, VELOCITY, PRESSURE GRADIENTS, MATHEMATICAL MODELS, STRESS ANALYSIS, DISSIPATION, TURBULENCE, TURBULENT BOUNDARY LAYER, MOMENTS, VORTICES, COMPUTATIONAL FLUID DYNAMICS, PRESSURE MEASUREMENT, FLOW FIELDS, APPROXIMATION(MATHEMATICS), SHEAR STRESSES, KINETIC ENERGY, VECTOR ANALYSIS, TWO DIMENSIONAL FLOW, NAVIER STOKES EQUATIONS, VISCOSITY, FLOW SEPARATION, STATIC PRESSURE, WING BODY CONFIGURATIONS, PRESSURE DISTRIBUTION, REYNOLDS NUMBER, LASER VELOCIMETERS, MOMENTUM TRANSFER, TURBULENT DIFFUSION.

Subject Categories : Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE