CFD modeling of a centrifuge for oil - water separation

Abstract

Centrifugation is an efficient, economical and environmentally friendly method to remove un-desirable water content from oil and water mixtures and separate out the desired oil content.Moreover, the disc stack centrifuges are widely used for separating liquids of different densi-ties and applied in industrial coconut oil clarification as well.The main focus of this research work is to model the fluid flow inside the Westfalia discstack centrifuge using Ansys Fluent and identify the flow behavior. With the availability of thelimited computer hardware facility, the model has been run without the discs to avoid com-plexities. In the developed 3 dimensional model, the fluid dynamic behavior of the multiphaseflow has been considered and modeled using the VOF multiphase model available in fluent.The step by step procedure of the model development has been discussed such as the veryfirst stage of geometry selection, drawing and importing to the fluent, mesh generation, allsolution set ups and even the two stage simulation procedure.The simulation results of this research work provides an out line of the resulted flow param-eters of velocity and pressure profiles, turbulent effects such as turbulence intensity, turbulentkinetic energy, and specific dissipation rate and also the phase volume fractions which havebeen saved in every critical stage of the simulation process. Despite the phase volume fractionwhich has been experimentally validated, all other results were theoretically validated.CFD modeling of flow behavior inside the centrifuges is not a popular topic among theresearchers due to the complex flow patterns and the requirement of advanced computer hard-ware facility. However this research work provides a platform to model the similar flow be-haviors and even to model the same case including the discs.