Turbomachine comprising an annular casing and a bladed rotor

摘要

A casing treatment for a fan or compressor stage 10 of a gas turbine engine comprises circumferential grooves 16A, 16B, 16C, 16D and 16E which extend in a series disposed between the leading edges 20 and trailing edges 22 of blades 6 of a fan or compressor stage 10. The grooves 16 vary in depth d in order to optimise the stall margin of the fan or compressor stage 10 while preserving peak efficiency.

主权项

1. A turbomachine comprising an annular casing and a bladed rotor which is rotatable within the casing, each blade of the rotor having a leading edge and a trailing edge, and a blade tip which travels over a swept region of an internal surface of the casing, the swept region being provided with a series of axially spaced circumferential grooves, each groove comprising a separate ring;
wherein: the depths of the grooves decrease monotonically from one of the grooves having a maximum depth to a groove at the end of the series corresponding to the trailing edge; and the depths of the grooves decrease monotonically from the groove having the maximum depth to a groove at the end of the series corresponding to the leading edge.