Abstract: A counter-rotating blade stage in lieu of a stator stage may compensate for relatively low rotational speed of a gas turbine engine spool. A first spool may have at least two compressor blade stage and at least two turbine blade stage. A combustor is located between the at least two compressor blade stage and the at least two turbine blade stage along a core flowpath. The at least two counter-rotating compressor blade stage is interspersed with the first spool at least two compressor blade stage. A transmission couples the at least two additional compressor blade stage to the first spool for counter-rotation about the engine axis.

Abstract: A counter-rotating blade stage in lieu of a stator stage may compensate for relatively low rotational speed of a gas turbine engine spool. A first spool may have at least one compressor blade stage and at least one turbine blade stage. A combustor is located between the at least one compressor blade stage and the at least one turbine blade stage along a core flowpath. The at least one counter-rotating compressor blade stage is interspersed with the first spool at least one compressor blade stage. A transmission couples the at least one additional compressor blade stage to the first spool for counter-rotation about the engine axis.

Abstract: Snow is made, for use on ski slopes and the like, using compressed air at a pressure substantially less than 95 psig, preferably around 30 psig. The air is provided to a snow making head or snow gun, where it is flowed through an air nozzle having effective diameter D. The air stream intersects a water droplet stream with angle A and at distance L from the air nozzle. Preferred angle A is in the range 70 to 110 degrees. The preferred ratio L/D is in the range 9:1 and 22:1. High pressure air from existing compressor systems is reduced to a desired substantially lower pressure by a central choked flow throttle upstream of an aftercooler, or by multi-stage throttles located near the snow making head. Water is added to the compressed air to substantially improve snow making, particularly when ambient relative humidity is low.

Abstract: A gas path flow blocker comprising a plurality of vanes each comprising a forward portion and an aft portion defining a plurality of gas paths, a forward ring comprising a central axis about which is circumferentially disposed the plurality of forward portions, and an aft ring disposed about the central axis about which is circumferentially disposed the plurality of aft portions wherein the forward ring and the aft ring are moveable with respect to each other to at least partially block the flow of a gas through the gas paths.

Abstract: The present invention relates to a bleed deflector for a gas turbine engine. The bleed deflector comprises an inlet portion for receiving bleed air from the engine, a perforated top plate for discharging the bleed air into a duct, and an aerodynamically shaped strut for positioning the perforated top plate above an inner wall of the duct to allow dilution air to flow beneath the top plate.

Abstract: The present invention relates to a bleed deflector for a gas turbine engine. The bleed deflector comprises an inlet portion for receiving bleed air from the engine, a perforated top plate for discharging the bleed air into a duct, and an aerodynamically shaped strut for positioning the perforated top plate above an inner wall of the duct to allow dilution air to flow beneath the top plate.

Abstract: A snowmaker is comprised of a head which has an outer ring of nozzles which form a flow of primary water into droplets which move downstream preferably along paths running at a slight radially outward angle, together with a central nucleator which discharges frozen nuclei particles outwardly from a plurality of atomizers at the downstream end cap end of the nucleator. The nucleator is readily disconnectable from the ring. Secondary water flow is fed to the nucleator so it swirls at high velocity within, to greatly enhance the warming effect of the water on the nucleator parts, and to thereby inhibit accumulation of exterior ice. The secondary water is mixed with compressed air as they both enter the atomizers of the end cap. A resultant flow of nuclei from the atomizers is discharged so the flow merges with the plume of primary water droplets from the nozzle. Preferably, flat spray nozzles are used.

Abstract: A compact heat exchanger system 52 for a duct 32 of a gas turbine engine 10 is disclosed, the heat exchanger system being disposed between two locations having an adverse pressure gradient. Various construction details which reduce the impact of the system 52 on engine efficiency, provide acceptable levels of drag, and reduce the possibility of foreign object damage are developed. In one embodiment the system has a low profile inlet 58 adjacent the inner wall 36 of a fan duct and has a flow path 56 extending from the inlet 58 to the outlet 62 which is continuous under all operating conditions of the engine.

Abstract: An inlet-outlet module 108 having both an inlet 58 and an outlet 62 for a heat exchanger system 52 is disclosed. Various construction details which improve the stiffness to weight ratio and the aerodynamic smoothness are developed. In one embodiment, the module 108 is formed of a one piece casting having a lobed mixer 94 at the outlet.

Abstract: A modified exhaust tailpipe especially for use with an aircraft turbofan engine utilizing a noise suppressor. The modified tailpipe is connected to the exhaust duct of the engine. The forward end of the tailpipe is essentially the same diameter as that of the exhaust duct of the engine. The contour of the tailpipe is such that it increases in diameter to form a bulge to increase the flow area for fan gases in the area of a mixer which is supported within the forward end of the tailpipe exhaust system. This improves the operating efficiency of the jet engine.

Abstract: A baffle insert or sleeve is disclosed for the integration of the downstream pressure tap into a pressure regulation valve ("PRY") for an aircraft environmental control system ("ECS"). The purpose of this insert is to return the flow, disturbed by the pivoting disk of a butterfly valve, to a more normal distribution within the length of the valve body. This allows the PRV downstream pressure tap to be part of the valve, instead of it (along with additional plumbing) being located four more pipe diameters beyond the valve housing.

Abstract: A thrust reverser (30) of a gas turbine engine (10) includes a blocker door (36) and a plurality of cascades (38). The thrust reverser (30) and the blocker door (36) have a stowed position and a deployed position. In the deployed position the blocker door (36) "leaks" airflow therethrough without generating substantial forward thrust. The leaked airflow reduces the amount of total airflow that must be accommodated by the cascades (38) of the thrust reverser (30), thereby decreasing the overall size of the cascades (38) and of the associated thrust reverser hardware and subsequently reducing the overall weight thereof.

Abstract: An internal flow mixer is attached to the rearward end of a turbofan engine for inverting the engine fan and core streams. Rearwardly of the internal flow mixer is a multi-lobed exhaust nozzle which mixes ambient air with the gases flowing from the flow mixer. An ejector housing lined with acoustic absorption material receives the flow from the exhaust nozzle and discharges the thrust producing gases in noise abatement condition.

Abstract: An anti-icing system for a nacelle of a gas turbine powerplant is disclosed. Various construction details have been developed which provide means to exhaust fluid from an inlet shell cavity and into an external medium. In one embodiment, the exhaust means (62) includes a plurality of aerodynamically shaped vanes (66) disposed within the inlet shell cavity (52) and a plurality of exhaust slots (68) wherein each of the vanes is adjacent one of the exhaust slots. The vanes are adapted to turn a portion of the body of fluid flowing within the inlet shell cavity to a direction substantially normal to the direction of flow of the external medium.

Abstract: To enhance stall margin without degrading engine performance the case of the fan of a fan-jet engine is treated by incorporating a passageway to remove flow from the main flow stream. The location and amount of the low momentum flow relative to the rotor being removed is critical. The flow is removed at a judicious location downstream of the leading edge of the rotor blade and returned at a judicious location upstream of the point of removal. The amount of removed flow must be no greater than 8% of the total flow in the fan rotor. Anti-swirl vanes in the passageway and discreetly sized inlet and outlet passages of the passageway return the flow to the main stream at an increased velocity. The intake is so designed that it selectively removes only the weak low momentum flow relative to the rotor and encourages the strong mainstream flow to remain in the main gas stream.

Abstract: Inlet vortex ingestion is deterred when testing an engine (12) in a test cell (10). Ramp structures (26) are installed on the walls blocking 30% to 50% of the flow area. The apex (42) of these ramps is located adjacent the engine inlet (24) with the upstream faces (46) at about a 45.degree. angle.

Abstract: The outer shroud of an axial flow compressor is treated to remove the low momentum flow adjacent the tips of the compressor blades in a judiciously located and sized passageway that removes the low momentum flow relative to the rotor blades at a location downstream of the blades' leading edge and returned at a location upstream of the point of removal. It being critical that no more than 12% of the total flow in the compressor rotor is removed for treatment. Anti-swirl vanes in the passageway serve to remove or reverse the swirl component from the removed low momentum flow. The intake is so designed that it selectively removes only the weak low momentum flow relative to the rotor and encourages the strong mainstream flow to remain in the main gas stream.

Abstract: An anti-icing system for a nacelle of a gas turbine powerplant is disclosed. Various construction details have been developed which provide means to exhaust fluid from an inlet shell cavity and into an external medium. In one embodiment, the exhaust means (62) includes a plurality of aerodynamically shaped vanes (66) disposed within the inlet shell cavity (52) and a plurality of exhaust slots (68) wherein each of the vanes is adjacent one of the exhaust slots. The vanes are adapted to turn a portion of the body of fluid flowing within the inlet shell cavity to a direction substantially normal to the direction of flow of the external medium.

Abstract: A gas turbine engine having a turbine vane assembly including an integrally cast cooling fluid nozzle is disclosed. Various construction details are developed which disclose a cooling fluid nozzle including a flow passage having an exit and a wall. In one embodiment, the wall includes an angled leading edge which mates with a circumferentially adjacent trailing edge of an adjacent wall. The leading edge is tapered such that in a most open position of the turbine vane assembly the leading edge and the trailing edge circumferentially align. In a most closed position of the turbine vane assembly, the angled leading edge aligns with the trailing edge such that a step down is created in the circumferentially directed flow of the sealed cavity. The plurality of wall thereby produce a waterfall arrangement within the sealed cavity to reduce the windage losses.

Abstract: A prediffuser, immediately upstream of a dump diffuser for a gas turbine engine is constructed to have equal numbers of struts as there are fuel injectors in the annular combustor. The wedged shaped struts are disposed symmetrically about the annular diffuser. The relatively large blunt trailing edge enhances the circumferential expansion of the discharge air dumping into the dump diffuser which achieves a more uniform temperature profile of the cooling air cooling the burner liner and its associated components, and avoiding localized hot spots.