Numerical research on flow field starting of supersonic compressor in outlet-opening wind tunnel

Abstract

The process from test starting to supersonic flow state established in an outlet-opening wind tunnel，i. e. the starting problem of supersonic flow，has become a recognized challenge. In order to establish the feasible flow field starting method，and lay the foundation for the use of outlet-opening wind tunnel，three-dimensional numerical simulation research is carried out，which is based on a certain wind tunnel，and taken the panel blade of supersonic compressor as the research object. The failure reason of supersonic flow field starting on experimental condition is analyzed，and three flow field starting schemes are established. The results show that the starting failure reason is the formation of a strong normal shock wave at the leading edge of the cascade. Increasing the inlet total pressure alone cannot establish the supersonic flow. The supersonic cascade flow field can be started by increasing the overflow gap width on lower wall side，but the number of effective cascade passages is decreased and the boundary layer thickness is increased. Maintaining the width of overflow gap on the upper and lower walls at more than 1.0 pitch，the setting upper and lower supersonic walls in front of cascade and conducting suction can effectively start the supersonic flow field. The maximum fluctuation of outlet Mach number is 0.01，the maximum fluctuation of outlet flow angle is 0.09°. The periodicity can meet the experimental requirements.

Keywords

• outlet-opening wind tunnel
• supersonic
• flow filed starting
• compressor
• cascade flow field