By analyzing the transonic singlestage compressors NASA Stage 35

the results of numerical simulation and the experimental results were combined

proving the veracity of numerical simulation. The hole and slot bleeding were calculated by two ways

and the same results were got. At last

the results of hole bleeding and the slot were compared. Result showed that

the slot bleeding was better. The bleeding/cooling block of NUMECA software was easy to realize the bleeding

another way increased the difficulty and complexity of numerical simulation

but it agreed with the fact of bleeding on compressor. Before the bleeding

the efficiency improved

and the total pressure ratio declined little. At same time

stall margin was enhanced.