Turbulence modeling validation

TLDR

Experimental data for the selected flows is well established and widely used in turbulence model development. The study aims to assess how freestream turbulence, grid resolution, wall spacing, initial conditions, numerical methods, and Mach number affect turbulence model accuracy. Four turbulence models (k‑ε, k‑ω, SST, and Spalart–Allmaras) were evaluated against eight experimental flows—including free‑shear, boundary‑layer, and complex separated flows—by comparing mean velocity, spreading rates, pressure coefficients, skin friction, and shear‑stress predictions.

Abstract

The performances of four turbulence models are evaluated against eight selected experimental flow fields. The four models are the two-equation k-e model of Launder and Sharma, the two-equation k-a> model of Wilcox, the twoequation k-03 SST model of Menter, and the one-equation eddy-viscosity model of Spalart and Allmaras. The eight turbulent flows of the validation are four fully-developed freeshear flows, an incompressibl e boundary layer, and three complex flows with flow separation. The free-shear layer flows comprise a mixing layer, a round jet, a plane jet, and a plane wake flow. The three complex flows are comprised of an adverse-pressure-gradient boundary layer, an axisymmetric shock-wave/boundary-layer interaction, and a transonic RAE 2822 airfoil flow. The experimental data for these flows is well established and has been extensively used in model developments. The numerical predictions include mean velocity profiles, spreading rates, surface pressure coefficients, skin friction, and shear-stress profiles. Most significantly, this research includes a sensitivity study on the accuracy of the solutions with respect to the effects of freestream turbulence, grid resolution, grid spacing near the wall, initial conditions, numerical methods and codes, and free stream Mach number effects on incompressible flows.