In order to enhance the stall margin of transonic tandem rotor

a better understanding about its flow structure and stall mechanism is required. Thus

a high-loaded transonic tandem rotor was designed to perform a loading coefficient of 0.56 at tip tangent speed of 450m/s. Based on the simulation results

firstly

the tip flow field and stall mechanism of this tandem rotor with the shroud gap of 0.5mm was analyzed

and then the influence of different tip clearances and percent pitch values on stall mechanism was studied. It is indicated that the tip area of forward blade plays a prominent role in the stability of transonic tandem rotor. Along with the increase of tip clearance

the stall mechanism of tandem rotor also changes from the stagnation of aft blade tip area caused by wake and subsurface flow to the blocking of forward blade tip area caused by the tip leakage flow. The tandem rotor will achieve its best effect under high percent pitch(PP) value

and the stall onset position will move from the aft blade towards the forward blade with the increase of percent pitch.