STUDY ON THE SECONDARY FLOW AND IT′S CONTROL IN COMPRESSOR

The present paper is a final report of the study on the secondary flow in compressors.A systematic experimental investigations on the secondary flow of both the C4 and BC-6 airfoil cascades have been completed.A end-wall corner flow model has been provided.The C4 airfoil variations of the outlet angle along the blade height have been calculated by the secondary flow theory.They approach to the experimental results.The influence of the tip clearance on the blade stall flutter is also investigated in the flutter experiment of the BF-1 compressor rotor.An experimental study on the reduction of secondary flow is carried out by using both “Heading Edge Sweep” and “End Bending” techniques.The total pressure loss coefficients of these two cascades decrease significantly.The results of the whole compressor flow field calculation of the compressor “End Bending” cascades are in good agreement with the experimental data.Some important conclusions are drawn to reveal the real flow mechanisin in the compressor and to develop new compressor flow physical models.It is of great value for engeerning application of the secondary flow control.