Evaluation of Five Turbulence Models for Accurate Numerical Simulation of 2D Slot Nozzle Ejector

Abstract

Accurate numerical simulation of high speed ejector flow is critical for design and optimization of nozzle ejector systems. Computational Fluid Dynamics (CFD) modeling of the turbulent mixing of a high speed jet with subsonic flow requires a turbulence model that can predict the flow field with an acceptable accuracy. In this paper, we consider five turbulence models – one equation Spalart-Allmaras (SA) model, two-equation k-e and Shear Stress Transport (SST) k-ω models, four equation Transition SST k-ω turbulence model and Scale Adaptive Simulation (SAS) SST k-ω model. The accuracy of these models is evaluated by comparing the CFD predictions against the experimental data available from NASA for a 2D slot nozzle ejector in a variable area mixing section. In addition the effect of two boundary conditions at the nozzle inlet – the pressure condition and the mass flow rate condition, on solution accuracy is investigated. It is shown that the SST k-ω and the Transition SST k-ω turbulence models give the best overall agreement with the experimental data.