ANNULAR FLOW DUCT FOR A TURBOMACHINE THROUGH WHICH A MAIN FLOW CAN FLOW IN THE AXIAL DIRECTION

摘要

The invention relates to an annular flow duct (18) for a turbomachine, said flow duct (18) being arranged concentrically about a machine axis (2) running in the axial direction and being defined by a boundary wall (22, 24) of circular cross section for directing a main flow (26), wherein the boundary wall (22, 24) has a plurality of return flow passages (46) which are distributed over its circumference and through which in each case a partial flow (49) which can be detached from the main flow (26) at a bleed position (50) can be returned to the main flow (26) at a feed position (52) situated upstream of the bleed position (50), and having aerofoils (32), arrranged radially in the flow duct (18), of a blade ring, the aerofoil tips (42) of which lie opposite the boundary wall (22, 24), with a gap being formed in each case, wherein the aerofoils (32) are movable in a predetermined rotation direction (U) along the circumference of the boundary wall (22 ,24). In order to specify a compressor which is insensitive to pumping and flow separations, it is proposed that - as viewed in rotation direction (U) - the bleed position (50) of each return flow passage lie upstream of the corresponding feed position (52).