Investigation of stall recovery potential in a transonic compressor rotor

In order to evaluate the potential of stall recovery at different operating points during the stall process in a transonic environment, three-dimensional multi-passage numerical simulations were conducted on the transonic compressor, NASA Rotor 37. The results showed that the whole stall evolution process can be divided into three stages depending upon the possibility for the compressor to recover to a stable operating condition by reducing the outlet pressure. At the first stage of the stall process, the compressor could successfully be driven back to a stable operating state by decreasing the outlet pressure. In addition, it was observed that the time of the stall recovery process was shorter when the outlet pressure was lowered more. At the second stage of stall, the magnitude of the outlet pressure played a decisive role in determining whether the compressor could recover to a stable state. When the compressor operation moved to the third stage of the stall process, “stall hanging” occurred, which means that the compressor could not recover from the stall regardless of how much the outlet pressure was reduced.