Tip-leakage flow in a low-pressure compressor: comparison between low- and medium-fidelity modelings

Abstract This paper evaluates a low-order three-dimensional hybrid panel method (HPM) for predicting inviscid flow around low-pressure compressor rotors. This approach provides input to specific models for the tip-leakage flow (TLF) characteristics. With a computational cost under one minute, it enables rapid aerodynamic analysis and design exploration. Results are compared with Reynolds-averaged Navier-Stokes (RANS) simulations of the LMFA NACA65 low-speed rotor, using a vortex tracking algorithm to extract the TLF features. The study investigates the sensitivity to the inlet incidence and tip gap height on rotor aerodynamics and TLF. Key metrics are tip-leakage vortex (TLV) trajectory, circulation and mixing loss. The rotor aerodynamic behavior shows a good agreement between the two methods. Concerning the TLF characteristics, the HPM agrees quite well with RANS at tip gaps less than 1% of chord length, but struggles with the more complex TLF behavior at larger clearance. Despite limitations, HPM captures key TLF trends, to support early-stage design before higher-fidelity refinement.