Analysis of Leakage Flow Through Clearance on Rotor Face in Vane Compressors

The performance of compressors used for automotive air conditioners is affected greatly by leakage which flows through a clearance between a rotor face and a sideplate. There are some studies which analyze distributions of pressure and velocity on the rotor face under a certain boundary pressure distribution on the rotor circumference. In this study we analyzed the leakage flow through the clearance on the rotor face by using a more realistic boundary condition which considers that pressure on the rotor circumference changes periodically with rotation of the rotor. Because of less influence of inertial force than that of viscous force, the pressure and velocity distribution at each moment can be evaluated under a quasi-steady condition with an instantaneous pressure distribution on the rotor circumference. On the other hand, the average flow field on the rotor face must be analyzed under a boundary condition that pressure at each angular position on the rotor circumference is equal to the time average of pressure in a compression chamber which is facing that position.