Concept of Turbulence Modelling and Its Application in Open Channel Flow

Abstract

The foremost objectives of the particular study are to assess the working of the most popular RANS turbulence closure model in simulating river flows. For that reason, ANSYS-FLUENT package was used considering the simulation of uniform flows in straight channel with several different RANS turbulence closure models. Two approaches were used for the turbulent region and near-wall region, which are the standard k-ϵ model and a k-ω model respectively. On the other hand, Reynold Shear Model (RSM) is also studied upon and its pros and cons are taken into consideration with respect to the models like k-ϵ model and k-ω model. In comparison to the newly conducted experimental data under controlled system, models using ANSYS–FLUENT, a Computational Fluid Dynamics (CFD) code, are found to give suitable results. Computational Fluid Dynamics (CFD) is frequently used to as technique to investigate flow structures in developing areas of a flow field for the determination of velocity, pressure, shear stresses, effect of turbulence and others. A two phase three-dimensional CFD model along with the two equations isotropic eddy viscosity model and Reynold stress model (RSM) is used to solve the turbulence equation. This study aims to validate CFD simulations of free surface flow or open channel flow by using Volume of Fluid (VoF) in multiphase scheme and viscous (laminar) scheme by comparing the data observed in by the UK Flood Channel Facility (FCF).