Abstract: There is provided a ventilator to ventilate an airway of a patient. The ventilator has a conduit having an inlet and an outlet, said outlet configured to be connected to said airway; a gas delivery element in fluid communication with said inlet, said gas delivery element configured to deliver air in a sequence of ventilation cycles, each ventilation cycle defined by a corresponding tidal volume to be delivered to said airway via said conduit, each tidal volume corresponding to a difference between a start volume and an end volume of said gas delivery element for that ventilation cycle; a pressure sensor monitoring pressure within said conduit; a controller communicatively coupled to said gas delivery element and said pressure sensor, said controller performing reducing said tidal volume between a first ventilation cycle and a successive second ventilation cycle contingent upon said pressure exceeding a pressure threshold in said first ventilation cycle.

Abstract: A power supply arrangement (PSA) for an aircraft having an electrical system and an environmental control system (ECS) operatively connected to a cabin of the aircraft, the PSA has: at least one propelling engine; a secondary power unit (SPU) having a rotary engine, at least one generator in driving engagement with the rotary engine and operatively connectable to the electrical system of the aircraft, and at least one load compressor operatively connected to the rotary engine and pneumatically connected to a pneumatic circuit connectable to the ECS of the aircraft, the PSA having a propelling configuration in which the at least one propelling engine and the SPU are both powered and a hotel configuration in which the at least one propelling engine is unpowered while the SPU is powered, the pneumatic circuit pneumatically disconnected from the at least one propelling engine in both of the hotel and propelling configurations.

Abstract: A method for starting a turbocompounded engine system having an internal combustion engine and a turbomachinery driving a load, the method comprising: mechanically disengaging the internal combustion engine from at least one of the load and/or the turbomachinery before starting the internal combustion engine. The engine is allowed to warm up and then the engine is re-engaged with the at least one of the load and the turbomachinery.

Abstract: A method of controlling a speed of a gas turbine engine, the gas turbine engine including a high pressure spool and a low pressure spool rotating independently from one another, including determining a temperature-corrected rotational speed of the high pressure spool based on an actual rotational speed of the high pressure spool and on an air temperature measured outside of the gas turbine engine; controlling the rotation of the high pressure spool to maintain the temperature-corrected rotational speed of the high pressure spool at least substantially constant throughout a range of a power demand on the gas turbine engine; and controlling a rotational speed of the low pressure spool independently of the rotation of the high pressure spool.

Abstract: A method of controlling a speed of a gas turbine engine including a gas generator spool and a power turbine spool rotating independently from one another, including controlling a rotational speed of the gas generator spool according to a fixed relationship with respect to an outside air temperature throughout a variation of output power.

Abstract: A gas turbine engine fuel system has an ecology valve for withdrawing residual fuel from primary and secondary fuel manifolds upon engine shut-down. The ecology valve has primary and secondary reservoirs respectively connected in fluid flow communication with the primary and secondary fuel manifolds. The valve further has a reciprocating piston movable from a retracted position when engine start-up is initiated to an extended position which the piston assumes under normal engine running conditions. The movement of the reciprocating piston between the retracted and extended positions controls the flow of fuel from and to the primary and secondary reservoirs. A cross-bleed passage is defined in the reciprocating piston. The cross-bleed passage connects the primary and secondary reservoirs in fluid flow communication only when the piston is in its extended position. In this way, the cross-bleed flow between the primary and secondary fuel manifolds may be initiated only at the end of the engine start-up phase.

Abstract: There is provided a system and method for controlling an engine. A request signal indicative of a demand for the engine to output a required power level is first receive. A position control signal is then generated in response to the request signal. The position request signal is indicative of a first request for adjusting a present position of a variable geometry mechanism of the engine towards a commanded position to achieve the required power level. An acceleration rate control signal is further generated on the basis of the position control signal. The acceleration rate control signal is indicative of a second request for adjusting an acceleration rate of the engine in accordance with the commanded position of the variable geometry mechanism. The position control signal and the acceleration rate control signal are then output to the engine.

Abstract: A gas turbine engine fuel system has an ecology valve for withdrawing residual fuel from primary and secondary fuel manifolds upon engine shut-down. The ecology valve has primary and secondary reservoirs respectively connected in fluid flow communication with the primary and secondary fuel manifolds. The valve further has a reciprocating piston movable from a retracted position when engine start-up is initiated to an extended position which the piston assumes under normal engine running conditions. The movement of the reciprocating piston between the retracted and extended positions controls the flow of fuel from and to the primary and secondary reservoirs. A cross-bleed passage is defined in the reciprocating piston. The cross-bleed passage connects the primary and secondary reservoirs in fluid flow communication only when the piston is in its extended position. In this way, the cross-bleed flow between the primary and secondary fuel manifolds may be initiated only at the end of the engine start-up phase.

Abstract: There is provided a system and method for controlling an engine. A request signal indicative of a demand for the engine to output a required power level is first receive. A position control signal is then generated in response to the request signal. The position request signal is indicative of a first request for adjusting a present position of a variable geometry mechanism of the engine towards a commanded position to achieve the required power level. An acceleration rate control signal is further generated on the basis of the position control signal. The acceleration rate control signal is indicative of a second request for adjusting an acceleration rate of the engine in accordance with the commanded position of the variable geometry mechanism. The position control signal and the acceleration rate control signal are then output to the engine.

Abstract: A method of controlling a speed of a gas turbine engine including a gas generator spool and a power turbine spool rotating independently from one another, including controlling a rotational speed of the gas generator spool according to a fixed relationship with respect to an outside air temperature throughout a variation of output power.