To explore the effects of boundary layer suction (BLS) on a transonic cascade

several experiments were carried out on an intermittent cascade wind tunnel.The results of different locations in relation to the point for passage shock wave projection of various suction coefficients have been investigated.Experimental results show that:when the location of BLS slot is in front of the point for passage shock wave projection

the local Mach number around the suction slot is increased and cascade performance is deteriorated.The loss coefficient increases with the enhancement of suction coefficient for both higher subsonic and supersonic inlet flow conditions

and when the suction coefficient is greater than 0.2%

the loss coefficient increases rapidly.When BLS slot is located behind the shock wave

the cascade performance is significantly improved

and the positive effect of BLS increases by the suction coefficient.Compared with the condition without suction

the loss coefficient reduces by 8% and the total pressure recovery coefficient increases by 5% when suction coefficient is 0.8%.