On computations of complex turbulent flow by using non-linear k-ω model

Abstract

This paper presents the performance of a new non-linear k-ω model for computations of turbulent flows and heat transfer in several different flow types. This model is developed by incorporating cubic terms that take into account the anisotropy of the Reynolds stresses, and the effects of extra strain rates due to a streamline curvature and the rotation of the flow passages. Five cases of turbulent flows are numerically simulated: fully developed turbulent flows in a channel without rotation, in a curved channel, in a rotating channel, and the flow over a two-dimensional blunt rectangular section. Both flow and heat transfer characteristics were examined for the above mentioned flow passages. The governing equations are discretized using a non-staggered finite-volume formulation employing a bounded higher-order differencing scheme. The comparisons are made among the experimental data and the results obtained by DNS, linear and nonlinear k-ω models. It is shown that the non-linear k-ω model generally gives superior results over the existing linear k-ω model by demonstrating better agreement with the data for both flow and heat transfer computations.