Pressure distribution in laminar radial flow through inclined disks

Abstract

Experimentally validated numerical analysis of the incompressible laminar isothermal flow between concentric inclined disks has been performed. The flow is supplied axially by a feeding orifice placed in one of the disks and becomes radial after being deflected by the inclined frontal disk. The work represents a further step towards the understanding of the refrigerant flow through automatic valve systems in refrigerating compressors. The three-dimensional Navier–Stokes equation was written for an axially transformed non-orthogonal coordinate system and solved using the finite volume methodology. Coupling between pressure and velocity was handled through the SIMPLE algorithm and second-order interpolation schemes were employed to approximate the variables at the control volume faces. The numerical model was validated through direct comparison of experimental radial pressure profiles. The flow is significantly affected by the inclination of the frontal disk, even for inclinations as small as 0.1°. For some combinations of Reynolds number, gap distance and inclination between disks, the pressure distribution showed regions of negative values which tend to pull the frontal disk towards the valve seat and also produce a restoring moment tending to make the disks parallel.