During the testing process of a marine gas turbine

high-pressure compressor has low efficiency

and there was a deviation between the distribution of pressure ration assignment and the design situation. After analysis

the large radial drop between the low-pressure compressor and high-pressure leads to significant losses in the intermediate transition section

further leading to poor quality of the inlet flow field of the high-pressure

which may be the main reason for the low efficiency of the high-pressure compressor. In view to this situation

the inner and outer wall profiles of the transition section are parameterized and represented by two quartic curves to seek optimization over a large range. At the same time

the support plate structure is optimized to further reduce airflow separation

and the optimization plan is ultimately determined. Through flow field analysis

it is found that the adverse pressure gradient flow on the inner wall of the transition section will affect the development of the wall boundary layer

leading to local flow separation and strong radial mixing

which is the main reason for the loss in the transition section. The optimization scheme controls the flow by moving the adverse pressure gradient flow position forward to reduce the total pressure loss. To verify the effectiveness of the scheme. Wind tunnel blowing tests were conducted on the optimization scheme. The results showed that the total pressure loss in the transition section was reduced to 18% after optimization

greatly improving the flow separation situation in the transition section.