Flow control mechanism of diffuser cascade corner-suction surface profiling design

Through numerical simulation, the optimal profiling under the design point and near stall point were compared, allowing for analyzing the flow field structure and compressor performance changes and exploring the mechanism of the two kinds of optimized profiling to improve the compressor performance. The optimization results showed that the suction surface of the optimal profiling under the design point was sunken, which reduced obviously the thickness of the boundary layer on the suction surface; and blend blade and end wall was close to the trailing edge, which reduced the low energy fluid in the corner zone and produced transfer under the impact of the pressure gradient. For the optimal profiling under the near stall point, the blend blade and end wall was close to the leading edge and the suction surface was convex, which promoted the fluid adhesion in advance when fluid entered the leading edge, and the leading edge separation area decreased sharply or even disappeared. The optimal profiling adapted to all working conditions can be constructed based on the two profiling controlling mechanisms and structure features, yielding extremely positive effect on many working conditions.