INVESTIGATION OF THE SECONDARY FLOW STRUCTURE IN THE MIXED FLOW TURBINE FOR A HIGH PRESSURE RATIO TURBOCHARGER

摘要

A numerical investigation into aerodynamic features of the mixed flow turbine used in a high-pressure ratio turbocharger was conducted. The S-A turbulence model and Jameson's center scheme have been applied in order to get good viscous resolution, accuracy and computing efficiency. Limiting streamlines on the wall surface as well as different flow characteristics, such as entropy generation of the cross sections, were evaluated, while detailed endwall flow and secondary flow structure were analyzed. The development of different vortex, especially the tip leakage vortex, passage vortex and horseshoe vortex were discussed. The results have shown that there is a great secondary flow feature and complicated vortex system in the mixed flow turbine.