NUMERICAL SIMULATION OF FLOW FIELDS OF VARIABLE GEOMETRY TURBINE WITH SPHERICAL ENDWALLS OR NONUNIFORM CLEARANCE

摘要

To rotate the vane of variable geometry turbine, the end walls contours of the turbine have to be spherical. If the end walls are cylinders, there will be nonuniform clearances between the ends of the vane and the end walls. In these two cases, the flow fields of the rotated vanes are simulated and compared. Special attentions are paid to the flows in the spherical clearances and nonuniform clearances under four rotating angles. The leakage flow and the loss are investigated and analyzed in this paper.