Numerical Simulation of Flow between Two Parallel Co-Rotating Discs

Abstract

The study of fluid flow between two rotating discs aims to predict flow characteristics. In this paper numerical simulation is used to investigate axisymmetric swirling flow between two parallel co-rotating discs. Methodology entails, firstly, inputing parameters from CFD software are into previos study developed dimensionless radial velocity model for flow between two discs to obtain dimensional radial velocity of the model. Secondly, previous study parameters are used to perform numerical simulation on laminar and turbulent flows between two parallel co-rotating discs. The numerical simulation results are compared to previous study results. Then comparative numerical simulations was carried out on laminar and turbulent flows using CFD software. Results obtained showed that for the this study dimensional radial velocity and previous study dimensionless radial velocity, radial velocity distribution increase proportionately from the disc surface at 0m/s to 2208.00m/s and 0 to 0.0002396 respectively, at the domain centre. And both results satisfy initial inlet and boundary conditions with resultant parabolic profiles. In the study, it is shown that turbulent flow radial velocity profile is smoother than for laminar flow. The radial velocity increases from 0 at the walls to 0.15m/s before decreasing to - 0.2m/s at the mid-centre for laminar flow while for turbulent flow the radial velocity intitially increases from 0 at the walls to 0.15m/s before decreasing to -0.06m/s at the discs centre; while for laminar flow, swirl velocity decrease from approximately 2.55m/s to 0.55m/s and for turbulent flow the swirl velocity decrease from approximately 2.84m/s to 1.62m/s. The turbulent flow swirl velocity profile seen to be smoother than for laminar flow around the discs centre. The study further showed that for fluid near the discs surfaces radial velocity net momentum is radially towards the outlet with flow laminar in the boundary layer region and the velocity turbulent towards the domain centre. For static pressure, laminar flow maximum and minimum static pressure 2.48pa and -0.033pa respectively, while for turbulent flow maximum and minimum static pressure were 0.00 and -0.0024pa. The developed previous study model can therefore be used to predict radial velocity distribution between steady axisymmetric flow between two parallel co-rotating discs.