TURBOMACHINE OVERROTOR DEVICE Russian patent published in 2002 - IPC

FIELD: axial flow turbomachines. SUBSTANCE: invention relates to overrotor devices with recirculating flow of medium in stages of axial flow turbomachines. Proposed device has ring duct wall with space outside duct and rotor blades rim. Radial clearance is formed between peripheral end faces of blades and duct wall. Duct wall is provided with rows of holes communicating duct with space outside duct, holes being located above and below leading edges of rotor blades in direction of flow. Holes in duct wall located above leading edges of rotor blades in direction of flow are made in form of rows of slots orientated circumferentially in direction of rotation of rotor blades. Holes in duct wall located below leading edges or rotor blades are made in form of slots orientated in direction of flow in inter-blade channels of rotor blades. Edges of each row of slots of duct wall orientated circumferentially are arranged in space of duct below in direction of flow than edges of each corresponding row of slots orientated circumferentially in space outside duct and at a smaller radial distance from axis of rotation of rotor blade rim than distance from axis of rotation to peripheral end faces of rotor blades. In duct wall of each slot orientated in direction of flow in inter-blade channels of rotor blades, edges in space of duct in circumferential direction as to rotation of rotor blades are located higher in flow than edges of each corresponding slot in space outside duct. EFFECT: enlarged range of stable operation, increased efficiency, reduced compressor noise level. 4 dwg