Improved Predictions of Transonic, Low Aspect Ratio, Axial Compressor Stage Performance and Tip Clearance Effects

摘要

The Compressor Aero Research Lab (CARL) of the Turbomachinery Branch, Turbine Engine Division recently conducted a tip clearance study to determine the performance impact of three different tip clearances on the Stage Matching Investigation (SMI) Fan single stage test article. The overall performance map for each clearance was obtained experimentally along with detailed discharge plane and over-the-rotor unsteady pressure measurements at selected operating conditions. Computational Fluid Dynamics (CFD) simulations were performed at design speed for each of the three clearance configurations. In general, the computational predictions of overall stage performance agreed well with the experimental measurements, except for a difference in massflow rate. The current study improves upon the previous predictions, by improving the CFD model to more accurately represent the physical conditions of the experiments. The inlet boundary condition was updated to reflect the total pressure profile in the upstream boundary layer, versus the uniform total pressure imposed at the inlet of the previous simulations. The error in choked massflow was reduced from approximately 4% in the previous work to approximately 3% in the current study.