CFD (REALIZABLE K-ε) AND COLD-FLOW TESTING FOR THE DESIGN OF AIR-AIR EJECTORS WITH TRIANGULAR TABBED DRIVING NOZZLES

摘要

This paper describes an investigation in which a commercial CFD software package has been used to evaluate the performance of air-air ejectors with triangular tabbed driving nozzles. The Realizable k-ε turbulence model was employed and CFD predictions were evaluated against experimental results. Ejector performance was measured on the basis of pumping, mixing, and back-pressure. It was discovered that CFD models were generally capable of predicting trends in pumping and mixing, but were unable to account for appropriate magnitude. In addition, CFD did not accurately represent the strength of the streamwise vortices generated by the tabs. At increased tab angles, CFD predicted values of back-pressure very well. However, under the 90° tab configuration, back-pressure was severely under-predicted.