Influence of Shock Wave on Loss and Breakdown of Tip-Leakage Vortex in Turbine Rotor with Varying Backpressure

In modern turbine rotors, tip-leakage flow is a common phenomenon that accounts for about 1/3 of the stage loss. Studies show as imposed load increases, shock wave appears in tip region, which causes significant interference on leakage vortex. present study, numerical simulations are carried out to investigate influence loss and breakdown The obtained results indicate with no effective control flow, vortex has an approximate exponential growth up 10 times outlet Mach number increases from 0.67 1.15 corresponding proportion total sharply 30.2%. It found stagnation position changes backpressure amplitude variation along axial direction 0.13 Cx. inferred core may be affected by periodical passing downstream blade induced pressure fluctuation result additional vibration this rotor blade. unstable supersonic it transfer low-velocity bubble its region. concluded mainly originates interferences wave, while internal cause such centrifugal instability