Numerical Study of a Small-Scale Turbomachine Device

Abstract

Rotary positive displacement pumps take a wide range of usage due to its compact size.Moreover, they provide an approximately constant flow at a fixed speed.The sliding-vane pump is a type of rotary positive displacement pumps whichhave a varied application including fuel pumping, power steering system, circuit lubrication system and automatic transmission system.Fluid behavior costs a lot to be seen inside the pump during operation experimentally.Otherwise, numerical programswhichdepend on Computational Fluid Dynamics (CFD), became anadequatetool todesign and optimize the pump. The basic challenge is that the flow volume changes continuously over the time. Therefore, numerical solver must be able to deform and generate the mesh every time-step. The objective of the current thesis is to investigate the sliding vane pump performance numerically and validate the results with experimental work. A three-dimensional modelisusedtoperformthistask.ANSYS-Fluent16.0isusedtosolveReynoldsAveragedNavierStokesequations (RANS)andturbulencemodelequations. The precise numericalmodelincludesawiderangeofissues,fromgridgenerationtoturbulencemodeling.Theseissueshavebeentaken into considerationandthenumericalresultsarecomparedwiththeresults of the experiment which conducted in the lab. The model has given a similarresultto the experiment results, with a deviationless than 6% in the flow rate.Accordingly,differentparametersareusedto examinetheperformance of the vane pump including the number of vanes and the gap height between the vane tip and stator, at different rotational speeds and pressures.Numerical results for themodel with eight-vanes and the model of 0.1 mm gap height gave the largest flow-rate and the best performance as well.