Analyzing the Turbulent Flow Characteristics by Utilizing k-ϵ Turbulence Model.

Abstract

This study attempts to illustrate the behavior of a fully developed turbulent flow by using k-ε turbulence model. A two dimensional smooth bend channel is adopted for this experiment and water was chosen as working fluid. The Reynolds number was gradually increased to predict the diversity in turbulent kinetic energy (TKE), turbulent dissipation rate, turbulent intensity and eddy viscosity. Primarily the flow has been solved by employing three distinct k-ϵ turbulence models namely, Standard, Renormalization-group (RNG) and Realizable model. After experimenting with ten different sample (from 74E03 to 298E03) of Reynolds numbers, each of these analyses explicitly showed that Standard k-ε model gives much higher value of any aforementioned turbulent properties with respect to other two equation turbulence models. Later it’s been discovered that TKE obtained from Standard k-ω model is almost same as Realizable k-ε model (for Re=298E03, the difference is about 1.8%). It has been observed that the skin friction coefficient at the bend region obtained from different two equation models (Standard, Realizable and RNG k-ϵ model and Standard k-ω model) are almost similar to each other for each sample of Reynolds number. Quadrilateral elements were taken into consideration for grid generation in this analysis. Also, to decrease cost and to achieve further accuracy as well as reduced time consumption mapped faced meshing was utilized.

Effects of Cross Jet on Turbulent Main Stream Flow in A Non-Circular Elbow – A Numerical Approach

“…Hossain and Hossain [6] analyzed the velocity distribution and formation of flow pattern throughout the bent channel and compared the computational results with   k and Reynolds Stress Model. In another study, Hossain, Hossain, Pramanik and Ahmed [7] investigated the deviation of turbulent kinetic energy, turbulent dissipation rate, eddy viscosity and turbulent intensity with the rise of Reynolds number through the bent region of curved pipe using   k and k   turbulent model. Rathore, Mondloe and Upadhyay [8] analyzed the flow characteristics of 90 0 bent pipe computationally using finite volume method and compared the results so obtained with the straight pipe having the equal length using ANSYS Fluent.…”