Aerodynamic effects of solidity on low-speed axial compressors

A parametric experimental study was conducted to determine the aerodynamic effects of solidity on low-speed axial compressors. The results show that total pressure ratio and efficiency vary monotonically with solidity, and interestingly the influencing trend reverses progressively with the compressor throttling to the stall boundary. It is supported by the five-hole probe traverse, which demonstrates the blockage is generally reduced with the increasing solidity near the stall boundary, and vise verse for the peak efficiency point. Also, the relation between stalling static-pressure-rise coefficient and normalized diffusion length was presented and compared with the data in the previously-published literature. An unexpectedly great agreement with the correlation is shown, which convincingly confirms its effective application in predicating the compressor boundary as a simplified approach. And unsteady transducers are employed to measure rotor tip flow, the results of which indicate there exists more complex mechanism of prestall disturbances needed to be studied further.