Abstract: A power turbine speed control system for a helicopter is disclosed which includes components for generating a power turbine speed signal based upon a demanded rotor speed, a high-order filter for filtering the power turbine speed signal by effectuating a rapid attenuation of main and tail rotor torsional frequencies in the power turbine speed signal without compromising phase at low frequencies, and a governor for providing isochronous power turbine speed and rotor speed control based upon the filtered power turbine speed signal.

Abstract: The invention relates to a method for decreasing the level of carbon dioxide present in the fumes discharged by a power generator burning a mixture of a combustive agent and of a fuel containing hydrocarbons, wherein a gaseous mixture comprising at least part of said combustive agent and at least part of said fumes is compressed, all or part of the carbon dioxide present in the compressed gaseous mixture is eliminated by absorption, a fuel is mixed with the gaseous mixture, the resulting mixture of fuel and gaseous mixture is burnt and the fumes from the combustion process are expanded. The invention also relates to a power generator for implementing said method.

Abstract: A reheat heat exchanger is provided particularly for use in Rankine cycle power generation systems. The reheat heat exchanger includes a high pressure path between a high pressure inlet and a high pressure outlet. The reheat heat exchanger also includes a low pressure path between a low pressure inlet and a low pressure outlet. The two paths are in heat transfer relationship. In a typical power generation system utilizing the reheat heat exchanger, the high pressure inlet is located downstream from a source of high temperature high pressure working fluid. An expander is located downstream from the high pressure outlet and upstream from the low pressure inlet. A second expander is typically provided downstream from the low pressure outlet. The reheat heat exchanger beneficially enhances the efficiency of power generation systems, particularly those which utilize expanders having inlet temperatures limited to below that produced by the source of working fluid.

Abstract: A method facilitates assembling a gas turbine engine assembly. The method comprises providing at least one propelling gas turbine engine that includes a core engine including at least one turbine. The method also comprises coupling an auxiliary engine to the propelling gas turbine engine such that during operation of the propelling gas turbine engine, at least a portion of the airflow entering the propelling gas turbine engine is extracted from the propelling gas turbine engine upstream from the core engine turbine, and channeled to the auxiliary engine for generating power.

Abstract: There is provided a low-emission, staged-combustion power generation system and associated method for generating power. The power generation system and method combust a carbonaceous fuel with an oxidizing fluid, both of which are substantially free of nitrogen and sulfur, to generate power, for example, in the form of electricity, without the formation of nitrous oxides (NOx) and sulfur oxides (SOx). Efficiency is enhanced using a multi-staged combustion, in which the carbonaceous fuel is partially combusted before passing through a first power take-off device and subsequently reheated and passed through one or more additional power take-off devices. Additionally, exhaust gases from one or more of the power take-off devices can be extracted and processed to provide quantities of useful products such as hydrogen and methanol.

Abstract: An improved turbine engine topology, wherein the improvement comprises a repositioning, with respect to a conventional intercooled regenerative turbine engine topology, of exhaust gas output from a low pressure turbine stage to a regenerator, to an exhaust gas output from a high pressure turbine stage to the regenerator. The engine topology may additionally employ, as an intermediate stage between the high pressure turbine and the low pressure turbine, a feedback control system, whereby the exhaust gas output from the high pressure turbine stage to the regenerator flows through the feedback control. The engine topology may advantageously also employ an additional cooler and an additional exhaust gas output in the feedback control, whereby exhaust gas flows from the feedback control through the additional cooler to a high pressure compressor stage, or the exhaust gas can flow from the feedback control through a bottoming cycle to the high pressure compressor stage.

Abstract: An APU system includes a gas turbine engine having a low pressure spool, a high pressure spool and an electrical generator. The electrical generator is driven by the high pressure spool which is governed to a constant speed. Conversely, the low pressure spool is not governed at all, but is allowed to seek a speed that balances the power developed by the low pressure turbine (LPT) and power absorbed by the low pressure compressor (LPC). A step increase/decrease in electrical power demand is met with a step increase/decrease in fuel flow, which results in an overshoot/undershoot of the new equilibrium turbine inlet temperature TIT. The TIT returns to the new equilibrium when the LP spool has achieved it's new shaft speed and new equilibrium power balance. The HP Spool and generator maintain essentially constant speed and frequency, while the LP Spool responds to restore equilibrium.

Abstract: A power turbine speed control system for a helicopter is disclosed which includes components for generating a power turbine speed signal based upon a demanded rotor speed, a high-order filter for filtering the power turbine speed signal by effectuating a rapid attenuation of main and tail rotor torsional frequencies in the power turbine speed signal without compromising phase at low frequencies, and a governor for providing isochronous power turbine speed and rotor speed control based upon the filtered power turbine speed signal.

Abstract: In various embodiments, the present invention provides a means for improving gas turbine engine performance by applying fluid flow control to the inter-turbine duct joining a high-pressure turbine spool and an associated low-pressure turbine spool, allowing the low-pressure turbine spool to have a relatively larger diameter than the high-pressure turbine spool. One or more unobstructed fluid flow paths between one or more boundary layer suction ports disposed within the upstream end of the outer-body surface of the inter-turbine duct and the suction side of the associated low-pressure turbine nozzle are provided. Advantageously, the natural static pressure difference between these points results in a self-aspirating assembly. The fluid flow control provided by the respective suction and blowing forces generated allows for a relatively larger diameter low-pressure turbine spool and/or relatively fewer low-pressure turbine nozzles to be used than is possible with conventional systems, assemblies, and methods.

Abstract: A multi-spool turbofan engine has a plurality of circumferentially spaced poppet valves with diverters secured thereto for precisely controlling bleed of combustion gas aft of the high pressure turbine whereby the high pressure spool operates at high idle RPM so as to power accessories and the low pressure spool operates at low RPM so as to minimize noise and fuel consumption.

Abstract: An APU system includes a gas turbine engine having a low pressure spool, a high pressure spool and an electrical generator. The electrical generator is driven by the high pressure spool which is governed to a constant speed. Conversely, the low pressure spool is not governed at all, but is allowed to seek a speed that balances the power developed by the low pressure turbine (LPT) and power absorbed by the low pressure compressor (LPC). A step increase/decrease in electrical power demand is met with a step increase/decrease in fuel flow, which results in an overshoot/undershoot of the new equilibrium turbine inlet temperature TIT. The TIT returns to the new equilibrium when the LP spool has achieved it's new shaft speed and new equilibrium power balance. The HP Spool and generator maintain essentially constant speed and frequency, while the LP Spool responds to restore equilibrium.

Abstract: An engine core rotor shaft structure for gas turbine engine is disclosed, which includes an outer annular shaft body, an inner annular shaft body, high pressure turbine (HPT) rotor blades radially connected between the outer annular shaft body and the inner annular shaft body to hold the inner annular shaft body in the rear section of the outer annular shaft body, and a can type combustor mounted in a receiving chamber inside the outer annular shaft body to enlarge the diameter of the core shaft, to avoid vibration due to resonance, to save space occupation, to eliminate dissipation of heat, and to improve the thermal efficiency of the gas turbine engine.

Abstract: An aircraft engine turbine frame includes a first structural ring, a second structural ring disposed co-axially with and radially spaced inwardly of the first structural ring about a centerline axis. A plurality of circumferentially spaced apart struts extend between the first and second structural rings. Forward and aft sump members having forward and aft central bores are fixedly joined to forward and aft portions of the turbine frame respectively. A frame connecting means for connecting the engine to an aircraft is disposed on the first structural ring. The frame connecting means may include a U-shaped clevis. The frame may be an inter-turbine frame axially located between first and second turbines of first and second rotors of a gas turbine engine assembly. An axial center of gravity of the second turbine passes though or very near a second turbine frame bearing supported by the aft sump member.

Abstract: A power turbine speed control system for a helicopter is disclosed which includes components for generating a power turbine speed signal based upon a demanded rotor speed, a high-order filter for filtering the power turbine speed signal by effectuating a rapid attenuation of main and tail rotor torsional frequencies in the power turbine speed signal without compromising phase at low frequencies, and a governor for providing isochronous power turbine speed and rotor speed control based upon the filtered power turbine speed signal.

Abstract: The invention relates to a bypass turbojet comprising a primary duct, a secondary duct, a low-pressure compressor, a high-pressure compressor, and a structural intermediate casing arranged axially between said low-pressure compressor and said high-pressure compressor, said intermediate casing being equipped at its periphery with a plurality of support arms having platforms which internally delimit the secondary duct, in which bleed-off means are provided, allowing some of the gaseous stream delivered by the low-pressure compressor to be tapped off and led to the secondary duct. Said bleed-off means comprise means for tapping air from said primary duct which are arranged upstream of said intermediate casing and means for removing the air tapped from said secondary duct downstream of said support arms, these means comprising conduits arranged around said intermediate casing under said platforms.

Abstract: A gas turbine engine has a compressor, a combustor mounted downstream of the compressor, power turbine mounted downstream of the combustor, a counter-rotating compressor turbine having a temperature sensor at its outlet, a temperature control system for controlling the temperature at the outlet of the compressor turbine, and a fuel supply control system for supplying fuel to the combustor. The engine has a drive motor for causing the compressor to rotate and a motor control system having a motor power-up module with an input connected to the fuel supply control system, and a motor power output control module having a first input connected to the motor power-up module, a second input connected to the temperature sensor, and an output which is connected to the drive motor.