Gas turbine engine exhaust diffuser including circumferential vane

A flow passage comprising an exhaust diffuser in a gas turbine engine, the flow passage comprising:

• an inner boundary defined by an exhaust diffuser hub;
• an outer boundary defined by an exhaust diffuser shell, said outer boundary diverging radially outward at a predetermined angle and being radially spaced from said inner boundary so that an annular flow path for guiding an exhaust gas flow in an axial direction is defined therebetween;
• a source of compressed fluid;
• a plurality of strut structures, each having a radially directed axis extending between said inner and outer boundaries;
• a pair of radially opposing, spaced aerodynamic surfaces forming a flow control vane having a chord length extending in the axial direction, and leading and trailing edges at opposing ends of said chord length;
• said flow control vane being affixed to and extending between said strut structures, said flow control vane defining a ring located between said inner and outer boundaries and receiving fluid from said source of compressed fluid;
• first and second fluid discharge slots for discharging the compressed fluid from said trailing edge;
• a fluid control surface adjacent to said fluid discharge slots, said control surface extending beyond said trailing edge of said vane and having curved trailing edge portions adjacent each of said slots forming a Coanda surface;
• and
• said flow control slots being selectively provided with the compressed fluid from said source of compressed fluid to produce a Coanda effect along said control surface, the Coanda effect having a component in the radial direction effecting a turning of the exhaust gas flow in said flow path radially inward or outward toward one of said inner and outer boundaries.

A method of exhaust diffusion in a turbine engine comprising:

• providing a turbine engine having a turbine section and an exhaust diffuser section, the exhaust diffuser section including an inner boundary defined at least by a hub structure comprising at least a hub and a tail cone, the hub having an upstream end and a downstream end, the tail cone having an upstream end located adjacent the downstream end of the hub and a downstream end, and the tail cone tapering radially inward toward an axis of the diffuser, the exhaust diffuser section further including an outer boundary radially spaced from the inner boundary so that a flow path is defined therebetween;
• supplying a turbine exhaust gas flow to the flow path;
• and
• providing a flow of fluid from a source of compressed fluid to a vane located between the inner and outer boundaries, the flow of fluid flowing in a Coanda effect along a Coanda surface to entrain a portion of the exhaust gas flow to effect a biasing of the exhaust gas flow toward at least one of the inner and outer boundaries.