PERFORMANCE OF AN AIR-AIR EJECTOR: AN ATTEMPT AT NUMERICAL MODELLING

Abstract

The paper describes a numerical attempt to model the operation of an air-air ejector by means of a commercial numerical code. The obtained results are compared with the results of a laboratory experiment – particularly in relation to the diffuser of the modelled ejector. The substantial discrepancies between the performance characteristics obtained in the laboratory experiment and by numerical modelling are interpreted as a result of the absence of appropriate models of turbulence and mixing in the numerical code used. The paper also presents additional numerical simulations that emphasize the importance of unsteady phenomena (bifurcations of working fluid jet, turbulent mixing at the boundary of components) in the modelling of ejector equipment.