| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent reduction of compression efficiency of a centrifugal compressor by minimizing clearance formed between the tip end of a vane of a compressor wheel and inside surface of a shroud. SOLUTION: The centrifugal compressor of a turbofan engine has the shroud 32 for covering the tip end of the vane 16a of the compressor wheel 16 mounted on the outer shaft 12 with clearanceα. A longitudinal section of the shroud 32 has the upstream part 32a extending in the axial direction and the downstream part 32b extending at a curve from the downstream end of this upstream part 32a to the outside of the radial, and a wall thickness of the downstream part 32b is gradually increased from the upstream side to the downstream side. This prevents the clearanceαin the downstream part 32b of the shroud 32 having a large influence on compression efficiency from fluctuating, and can minimize reduction in performance of the shroud 32 caused by thermal expansion.</p> |
