Analysis of Turbulent Flow in a Pipe at Constant Reynolds Number using Computational Fluid Dynamics

Abstract

Computational Fluid Dynamics (CFD) based simulation procedures are considered to be an indispensable analysis and design tool in a wide and ever-increasing range of applications involving fluid flow. This work presents computational investigation of turbulent flow inside pipes of varying diameters. A computational fluid dynamics model of turbulent flow in the pipes is implemented with the help of ANSYS FLUENT 6.3.26 software. Two Reynolds Averaged Navier Stokes Turbulent models; the k and k

models are used for the simulation and the variation of axial velocity, skin friction coefficient and turbulent intensity along the length of the pipes is analyzed. The viscous boundary layer is expected to grow along the pipe starting at the inlet. It will eventually grow to fill the pipe completely (provided that the pipe is long enough). When this happens, the flow becomes fully-developed and there is no variation of the velocity profile in the axial direction. A closed-form solution to the governing equations can be obtained in the fully-developed region. The fluid used for this purpose is air and the pipe material is aluminium. The Reynold’s number is based on the pipe diameter and average velocity at the inlet and is taken as 10,000 for fully turbulent flow. The numerical results obtained from two models are compared with each other and validated against experimental data from the literature. Between the two models, the k-epsilon model was found to give better results.