Two shock control methods were presented in order to reduce the shock loss in highly-loaded transonic high pressure turbines. For the suction side shock
the controlled expansion designed concept
combined with a curvature based blade design method
was brought forward to control the flow expansion by adjusting the curvature distribution on the suction surface. The suction side shock strength and the pressure non-uniformity at the cascade outlet were effectively reduced with the decreased pre-shock Mach number at the trailing edge. The reduced shock method based on a bump designed on the suction surface was developed to control the pressure side shock effects. The shock/boundary-layer interaction and the reflected shock were obviously weakened with the pre-compression effect and the weakening effect as a result of the bump induced compression waves and expansion waves. In addition
analysis of controlled expansion and reduced shock methods indicated that their controlling effects on two shocks were independent
and thus could be used separately. With the combined shock control methods
numerical results showed a 29.66% reduction in the suction side shock strength
a 29.28% reduction in the pressure non-uniformity at the cascade outlet and a 12.11% reduction in the total pressure loss coefficient for the improved profile.