Effects of BLS on the shockwave structure and separation flow of fan rotor

The boundary layer suction (BLS) has been proved very effectively in Shockwave structure organizing and boundary layer separation controlling to enhance the working ability and decrease the loss of a cascade. The second stage rotor of a two stage fan was chosen as the research subject, the BLS was applied to the suction surface (SS) and pressure surface (PS) of the rotor blade. The interactions between shockwave and separation flow and the interactions between suction flow and separation flow were investigated and discussed in detail. By BLS, the position of the shockwave can be controlled, the structure of the shockwave through the passage can be changed and the boundary layer separation due to the shockwave can be avoided, and moreover, the complex structure in the separation region can be eliminated and the circulating ability of the flow passing through the passage can be enhanced, and therefore the performance of the whole stage can be improved.