Design and Application of Turbine Cascade Partitioned Endwall Profiling

The influence of partitioned profiling design based on a large-pitch highly loaded cascade is studied by numerical simulation. The partitioned profile is mainly composed of a pressure-side convex structure near the leading edge and a suction-side convex structure at the midstream and downstream sides of the passage. The influence of the change in the vertex axial position and peak value of the B-line on the secondary flow control is analyzed. In this paper, air (ideal gas) is selected as the flow media. The average static pressure at the outlet and the average total temperature at the inlet are kept constant. SST γ-θ is used as the turbulence model. The results show that the pressure-side convex structure suppresses the spanwise and pitchwise migration of the inlet flow by adjusting the static pressure distribution of the flow field, so the development of the pressure-side leg of the horseshoe vortex is effectively limited. The suction-side convex structure adjusts the static pressure distribution of the flow field and increases the included angle between the cross-flow and suction surface, so the accumulation of low-momentum fluid, the development of a corner vortex and the flow separation at the trailing edge of the suction-side surface are all suppressed near the endwall-suction corner. Consequently, the energy loss coefficient of the large-pitch highly loaded cascade is decreased from 0.0564 to 0.0485, representing a 25% reduction in secondary flow losses.