Effect of Passage Expansion Design on Aerodynamic Performance of Diffuser Passage Compressors

摘要

A unique, "Diffuser Passage Compressor" concept is presented which aims at minimizing axial compressor's stall margin deficit with tip clearance opening, i.e. reducing so called tip clearance sensitivity. Low-speed rig tests are performed to compare aerodynamic performance of a conventional (CNV) rotor and the diffuser passage (DP) rotor of the same aerodynamic loading. Tests reveal that DP rotor is aerodynamically more robust than CNV when tip clearance is doubled. Effects of passage design on DP rotor performance are experimentally and numerically investigated by modifying axial distribution of passage area expansion and by expanding the passage area toward the hub instead the tip. In some cases, aerodynamic robustness of DP rotor is degraded due to end-wall flow behavior. Proper passage design is essential to elicit desired performance of DP rotor.