Compressor Clearance Research Articles

Effect of pressure-side tip winglet with different heights and lengths on clearance flow in a compressor cascade

The clearance flow influence law and mechanism of pressure tip winglets with different fusion heights and lengths are investigated by numerical simulation methods based on a compressor cascade to weaken compressor clearance leakage and improve cascade aerodynamic performance. The result demonstrates that the tip winglet can improve the spanwise pressure flow and narrow the tip separation range, thereby suppressing the intensity of the leakage vortex. The enhanced effect on the leakage vortex is more significant when the tip winglet's fusion length range can include the leakage vortex's initial position. In addition, narrower fusion heights and longer fusion lengths enhance the improvement effect. The tip winglet provides the most significant effect, reducing total pressure loss by 0.64% and leakage by 16.8% when the fusion height is 1% blade height and the length is the whole chord.

Endwall Blockage in Axial Compressors

This paper presents a new methodology for quantifying compressor endwall blockage and an approach, using this quantification, for defining the links between design parameters, flow conditions, and the growth of blockage due to tip clearance flow. Numerical simulations, measurements in a low-speed compressor, and measurements in a wind tunnel designed to simulate a compressor clearance flow are used to assess the approach. The analysis thus developed allows predictions of endwall blockage associated with variations in tip clearance, blade stagger angle, inlet boundary layer thickness, loading level, loading profile, solidity, and clearance jet total pressure. The estimates provided by this simplified method capture the trends in blockage with changes in design parameters to within 10 percent. More importantly, however, the method provides physical insight into, and thus guidance for control of, the flow features and phenomena responsible for compressor endwall blockage generation.