A modern highly-loaded forward swept transonic fan rotor flow field was investigated numerically at multiple rotor tip clearance levels to obtain clearance sensitivities with respect to flow

efficiency and stall margin.Compared with a conventional radial leading edge profile that had aerodynamic equivalent manner

the forward swept rotor blades show significant reduction in clearance sensitivity.The benefits are more pronounced for the configuration with stronger tip clearance flows.No optimum clearance size for the present forward swept rotor is indicated.Detailed comparisons of tip clearance flow structures were used to explain the flow mechanisms responsible for the reduction in tip sensitivity and blockage with forward sweep.