Numerical Simulations of Flows Inside a Partially Filled Centrifuge

Abstract

A numerical study was conducted to predict the dynamics of gas/liquid flows in a partially filled cylinder undergoing moderate to rapid rotation. Two specific problems were considered: spinup from rest of a partially filled circular container and the steady flow field in a partially filled rotating circular cylinder with an overrotating lid. Numerical solutions of the time-dependent axisymmetric Navier-Stokes equations were obtained by using a homogeneous multiphase model. The evolution of the free surface along with the flow fields in both the gas and liquid phases are predicted. The computed results were compared with available experimental data. Details of flow field structures are examined by studying the numerical solutions. Radial profiles of axial and azimuthal velocities for both the liquid and gas phases are also presented. The model developed can be used for analyzing flows and mixing problems in complex-geometry centrifuges.