Design of an Aspirated Compressor Stator by Means of DoE

Abstract

This paper presents the design of an aspirated stator of a four-stage high-speed axial compressor. The aspiration of near-wall fluid at the suction side of the first stator is designed numerically by means of DoE (Design of Experiments). The design objective is a reduction or complete suppression of hub corner separation at off-design conditions. As operating point for the CFD-based design process, the last numerically stable operating point near the stall limit of the reference configuration at 80% of the design speed is chosen. As DoE factors the aspiraton velocity, the chordwise position, and the axial by radial dimensions of the aspiration slot are varied. Their effects on the two target values overall isentropic efficiency and total pressure ratio are investigated. All evaluated configurations show significant improvements in stage performance of all compressor stages be-cause of a reduction of hub corner separation. Based on the DoE correlation factors an optimization is performed. The optimum configuration shows an increase in overall isentropic efficiency Δηis of 1.3% to 90.98% whereas the total pressure ratio π is raised by 0.08 to 2.08.