Using tip injection to reduce blade count in a transonic fan

A time-accurate numerical investigation has been carried out on the impact of blade solidity on the performance of NASA Rotor-67. The change in solidity has been accomplished by changing the blade count. Furthermore, endwall injection has been applied to investigate the possibility of removing some blades, and then employing injection to improve the performance. Results show that reducing the blade count results in a shift to higher mass flow rates. It is further found that reducing the solidity reduces the compressor peak pressure rise. The near-stall efficiency, however, was slightly increased and then slightly decreased by removing the blades, which is presented and discussed. Endwall injection applied in this work was found to compensate the pressure loss caused by removing about 18 percent of the blades. Furthermore, it considerably increased the stable operating range. Therefore, injection can be used to reduce the blade count and produce a high-performance light-weight compressor.