Numerical analysis of tip leakage flow effect on compressor stability

To study the effect of tip leakage flow on the compressor stability, a tip leakage vortex model was developed, and implemented in the TUSIAC (three dimensional and unsteady stall inception analysis code) program. The program modeled rotors/stators as three dimensional actuator disks, where the viscous effect was reflected by the characteristic curve, and the three-dimensional unsteady Euler equations in the flow passages between them were solved, thus lower computational resources were required. The numerical simulation showed that the performance and stable margin of the compressor were degraded under the effect of tip clearance.The tip clearance did not change the type of the stall precursor, but shrinked the circumferential size of the stall cell, and made it rotate faster.The newly developed tip vortex model could predict the tip clearance effect on the compressor stability and the stall inception process, thus providing a practical approach to investigate the compressor stability and optimize the compressor design during the preliminary design phase.