Stochastic versions of stability equations are considered as a means to develop integrated models of transition and turbulence. Two types of stochastic models are considered: probability density function evolution equations for stability mode amplitudes, and Langevin models based on representative stability theories including the resonant triad model and the parabolized stability equations. The...

In this work, the non-isothermal Navier–Stokes equations are studied from the group theory point of view. The symmetry group of the equations is presented and discussed. Some standard turbulence models are analyzed with the symmetries of the equations. A class of turbulence models which preserve the physical properties contained in the symmetry group is built. The proposed turbulence models are...

In this paper, the similarity solution of turbulent boundary layer flow on the flat plate with zero pressure gradients is presented. By employing similarity variables the governing partial differential equations are transformed to ordinary ones with inconsistent coefficients and solved numerically with the use of Runge–Kutta and shooting methods in conjunction with trial and error procedure. Fo...

Predication of reattachment length of separated shear layers in low Reynolds number turbulent flow is a challenging task to evaluate the capabilities of different turbulence models, especially for MEMS applications. Physical significances of backward facing step and its industrial applications were discussed. Flow analysis of backward facing step in 2D as well as in 3D were carried out by using...

This paper presents a computational study of the separated flow in a planer asymmetric diffuser. The steady RANS equations for turbulent incompressible fluid flow and six turbulence closures are used in the present study. The commercial software code, FLUENT 6.3.26, was used for solving the set of governing equations using various turbulence models. Five of the used turbulence models are availa...

In this paper, several low and high Reynolds number versions of k-ε and Reynolds stress turbulence models have been evaluated in a channel and a square duct flow with and without a magnetic field by comparing the predictions with direct numerical simulations data. The simulations are performed using FLUENT solver. The additional source terms for magnetic field effects on turbulence have been in...