Author(s)

W. A. S. Kumara, B. M. Halvorsen & M. C. Melaaen

Abstract

In general, developing turbulent pipe flow is a transition from a boundary layer type flow at the entrance to a fully developed flow downstream. The boundary layer thickness grows as the distance from the pipe inlet increases. An accurate description of the velocity and pressure distribution within the entrance region is very important to calculate the pressure drop for hydrodynamic inlets. More important perhaps, the velocity distribution is needed for an analysis of forced convection and mass transfer in a tube entrance. In the current study, we report the results of a detailed and systematic numerical investigation of developing turbulent pipe flow. Two-dimensional, axisymmetric computational scheme has been devised for determining the flow development in the entrance region of a circular pipe at different Reynolds numbers. The simulations are performed using commercial CFD software ANSYS FLUENT 12.0. Non-asymptotic behavior observed in developing turbulent pipe flow is discussed in detail. The predicted results are also compared with literature data. Keywords: non-asymptotic behavior, turbulent flow, laminar flow, fully developed flow, computational simulations, axial velocity, velocity overshoot, wall shear stress. 1 Introduction Turbulent pipe flow is one of the most common fluid motion in industrial and engineering applications. The importance of knowing the length of pipe required for the turbulent flow to fully develop, i.e., the velocity profile to become nonvarying in the axial direction, has long been recognized. Consequently, several investigators have attempted to obtain solutions for incompressible turbulent

Keywords

non-asymptotic behavior, turbulent flow, laminar flow, fullydeveloped flow, computational simulations, axial velocity, velocity overshoot,wall shear stress