Endwall blockage in axial compressors

This paper presents a new methodology for quantifying compressor endwall bl ockage and an approach, using this quantification, for defining the links b etween design parameters, flow conditions, and the growth of blockage due t o tip clearance flow. Numerical simulations, measurements in a low-speed co mpressor, and measurements in a wind tunnel designed to simulate a compress or clearance flow are used to assess the approach. The analysis thus develo ped allows predictions of endwall blockage associated with variations in ti p clearance, blade stagger angle, inlet boundary layer thickness, loading l evel, loading profile, solidity, and clearance jet total pressure. The esti mates provided by this simplified method capture the trends in blockage wit h changes in design parameters to within 10 percent. More importantly, howe ver, the method provides physical insight into, and thus guidance for contr ol of the flow features and phenomena responsible for compressor endwall bl ockage generation.