Abstract: A redundant fuel metering system and method for a multi-stage combustor that utilizes a fuel metering valve EHSV from a less critical combustor stage fuel metering system as a redundant backup to the main metering valve EHSV. In the event of a failure of the main FMV EHSV, a control module signals a transfer system to switch control of the main FMV to the less critical combustor stage fuel metering system EHSV, thus maintaining control of the FMV for the main combustor. In doing this, the transfer valve then drives the less critical combustor stage fuel metering system FMV to its failsafe position while maintaining control of the main system.

Abstract: A passive flow splitting system for use in a turbine engine control system to provide split fuel flow to two fuel manifolds to supply primary and secondary fuel injectors for the particular combustion zones thereof utilizing intentionally different split ratios dependent on ascending or descending combustion fuel flow is provided. The system includes a passive fuel divider valve (FDV) that includes a primary piston and a secondary piston. The primary piston is moveable independently from the secondary piston during a portion of its stroke, and is hydro-locked to the secondary piston during another portion of its stroke. An ecology valve is also provided to purge the fuel from the primary and/or secondary manifolds during different modes of operation. A transfer valve is included to control the position of ecology piston of the ecology valve.

Abstract: A passive flow splitting system for use in a turbine engine control system to provide split fuel flow to two fuel manifolds to supply primary and secondary fuel injectors for the particular combustion zones thereof utilizing intentionally different split ratios dependent on ascending or descending combustion fuel flow is provided. The system includes a passive fuel divider valve (FDV) that includes a primary piston and a secondary piston. The primary piston is moveable independently from the secondary piston during a portion of its stroke, and is hydro-locked to the secondary piston during another portion of its stroke. An ecology valve is also provided to purge the fuel from the primary and/or secondary manifolds during different modes of operation. A transfer valve is included to control the position of ecology piston of the ecology valve.

Abstract: A passive flow splitting system for use in a turbine engine control system to provide split fuel flow to two fuel manifolds to supply primary and secondary fuel injectors for the particular combustion zones thereof utilizing intentionally different split ratios dependent on ascending or descending combustion fuel flow is provided. The system includes a passive fuel divider valve (FDV) that includes a primary piston and a secondary piston. The primary piston is moveable independently from the secondary piston during a portion of its stroke, and is hydro-locked to the secondary piston during another portion of its stroke. An ecology valve is also provided to purge the fuel from the primary and/or secondary manifolds during different modes of operation. A transfer valve is included to control the position of ecology piston of the ecology valve.

Abstract: A passive flow splitting system for use in a turbine engine control system to provide split fuel flow to two fuel manifolds to supply primary and secondary fuel injectors for the particular combustion zones thereof utilizing intentionally different split ratios dependent on ascending or descending combustion fuel flow is provided. The system includes a passive fuel divider valve (FDV) that includes a primary piston and a secondary piston. The primary piston is moveable independently from the secondary piston during a portion of its stroke, and is hydro-locked to the secondary piston during another portion of its stroke. An ecology valve is also provided to purge the fuel from the primary and/or secondary manifolds during different modes of operation. A transfer valve is included to control the position of ecology piston of the ecology valve.

Abstract: A fuel split control arrangement is provided. The arrangement includes a staged cooling flow control valve and cooling check valve. The staged cooling flow control valve and cooling check valve is connected between the primary and secondary tips of a nozzle in a turbine engine. The staged cooling flow control valve and cooling check valve includes a valve member arrangement operable to prevent fuel flow from the secondary fuel supply manifold to the secondary tip and simultaneously allow fuel flow from the secondary fuel supply manifold to the primary tip such that the primary tip receives fuel flow from both the secondary fuel supply manifold and the primary fuel supply manifold.

Abstract: A fuel pressure regulation system is provided. The fuel pressure regulation system includes a supply arrangement for supplying an outlet flow. The supply arrangement includes a primary pressure regulator and a bypass pressure regulator. The primary pressure regulator is operably connected to downstream pressures of each of a plurality of parallel metering circuits. The bypass pressure regulator is upstream from an output of a pump or pumps, which in combination with the primary pressure regulator, is operable to increase the output of the pump or pumps to accommodate for downstream pressure spikes in any one of the parallel metering circuits.

Abstract: A fluid distribution system includes a boost supply providing a fluid flow, and a fluid metering system downstream of the boost supply. The fluid metering system supplies fluid to a downstream device. A main fluid pump supplies at least a portion of the fluid flow to the fluid metering system. A shut-off valve is positioned upstream of a main fluid pump inlet. An actuation system is positioned downstream of the boost supply. The actuation system supplies fluid to one or more hydraulically-operated devices. An actuation pump supplies at least a portion of the fluid flow to the fluid metering system and to the actuation system. A first valve is positioned between the actuation pump and the fluid metering system. The first valve and the shut-off valve are operable to switch between the main fluid pump and the actuation pump as a source of fluid supply to the fluid metering system.

Abstract: A split control unit in a distributed flow unit includes a flow inlet configured to receive a fuel flow, a first manifold having flow lines to supply fuel to one or more primary nozzles, and a second manifold having flow lines to supply fuel to one or more secondary nozzles. In an embodiment, the second manifold is in fluid communication with the flow inlet. A metering valve has a first port in fluid communication with the flow inlet and with the second manifold. The metering valve is configured to supply a metered fuel flow to the first manifold. A flow passage is in fluid communication with, and runs between, a flow line of the first manifold and a flow line of the second manifold to allow for a continuous cooling flow in the second manifold when all of the one or more secondary nozzles are closed.

Abstract: A fuel pressure regulation system is provided. The fuel pressure regulation system includes a supply arrangement for supplying an outlet flow. A primary metering circuit is provided, an inlet of which receives a first portion of the outlet flow of the supply arrangement, the primary metering circuit comprising a fuel metering valve and a primary pressure regulator. The primary pressure regulator is connected to an outlet of the fuel metering valve. The system also includes at least one secondary metering circuit. The primary pressure regulator is operably connected to the at least one secondary metering circuit to sense a pressure of the at least one secondary metering circuit. The system also includes a bypass regulator connected in parallel with the primary metering circuit and the least one secondary metering circuit such that an inlet of the bypass regulator receives a second portion of the outlet flow of the supply arrangement.

Abstract: A fuel circulation system and methods are provided. The system includes a supply pump for providing an outlet flow of fuel. The system also includes at least a first and a second servo. The first servo is connected to an outlet of the supply pump. A flow regulation device is interposed between the first and second servos. At least a portion of the outlet flow from the supply pump is directed through the first servo, flow regulation device, and second servo and is returned to an inlet of the supply pump.

Abstract: An engine fuel system and methods are provided. The engine fuel system includes a supply arrangement for providing an outlet flow of fuel to a bypass metering arrangement. The bypass metering arrangement in turn provides a metered flow of fuel to a parallel metering system including a primary regulated circuit and one or more secondary metering circuits. The bypass metering arrangement is operable to maintain a substantially constant pressure differential across a fuel metering valve thereof, as well as provide the metered flow of fuel in response to downstream pressure demands of the parallel metering system.

Abstract: A fluid distribution system includes a boost supply providing a fluid flow, and a fluid metering system downstream of the boost supply. The fluid metering system supplies fluid to a downstream device. A main fluid pump supplies at least a portion of the fluid flow to the fluid metering system. A shut-off valve is positioned upstream of a main fluid pump inlet. An actuation system is positioned downstream of the boost supply. The actuation system supplies fluid to one or more hydraulically-operated devices. An actuation pump supplies at least a portion of the fluid flow to the fluid metering system and to the actuation system. A first valve is positioned between the actuation pump and the fluid metering system. The first valve and the shut-off valve are operable to switch between the main fluid pump and the actuation pump as a source of fluid supply to the fluid metering system.

Abstract: A fuel pressure regulation system is provided. The fuel pressure regulation system includes a supply arrangement for supplying an outlet flow. The supply arrangement includes a primary pressure regulator and a bypass pressure regulator. The primary pressure regulator is operably connected to downstream pressures of each of a plurality of parallel metering circuits. The bypass pressure regulator is upstream from an output of a pump or pumps, which in combination with the primary pressure regulator, is operable to increase the output of the pump or pumps to accommodate for downstream pressure spikes in any one of the parallel metering circuits.

Abstract: A fuel pressure regulation system is provided. The fuel pressure regulation system includes a supply arrangement for supplying an outlet flow. A primary metering circuit is provided, an inlet of which receives a first portion of the outlet flow of the supply arrangement, the primary metering circuit comprising a fuel metering valve and a primary pressure regulator. The primary pressure regulator is connected to an outlet of the fuel metering valve. The system also includes at least one secondary metering circuit. The primary pressure regulator is operably connected to the at least one secondary metering circuit to sense a pressure of the at least one secondary metering circuit. The system also includes a bypass regulator connected in parallel with the primary metering circuit and the least one secondary metering circuit such that an inlet of the bypass regulator receives a second portion of the outlet flow of the supply arrangement.

Abstract: An engine fuel system and methods are provided. The engine fuel system includes a supply arrangement for providing an outlet flow of fuel to a bypass metering arrangement. The bypass metering arrangement in turn provides a metered flow of fuel to a parallel metering system including a primary regulated circuit and one or more secondary metering circuits. The bypass metering arrangement is operable to maintain a substantially constant pressure differential across a fuel metering valve thereof, as well as provide the metered flow of fuel in response to downstream pressure demands of the parallel metering system.

Abstract: A fuel circulation system and methods are provided. The system includes a supply pump for providing an outlet flow of fuel. The system also includes at least a first and a second servo. The first servo is connected to an outlet of the supply pump. A flow regulation device is interposed between the first and second servos. At least a portion of the outlet flow from the supply pump is directed through the first servo, flow regulation device, and second servo and is returned to an inlet of the supply pump.

Abstract: An accessory flow recovery system includes an inlet that receives a first fluid flow, and a pump with a pump inlet and outlet. The pump inlet receives the first fluid flow from the inlet and discharges a second fluid flow from the outlet. The accessory flow recovery system has an actuation unit for supplying a third fluid flow to accessory components, a metering system to regulate the flow rate of the second fluid flow based on a flow demand, and an inlet pressurizing valve coupled between the outlet and the metering system. The inlet pressurizing valve regulates the second fluid flow between the pump and the metering unit. The accessory flow recovery system further includes a return switch valve to direct the third fluid flow to the metering system when the recovery system is operating in one mode, and to the inlet when the system is operating in another mode.

Abstract: A flow sensing dual pump switching system and method are provided that control the supply of fuel from a dual pump fuel system to a fuel metering unit. The system senses bypass pressure from the fuel metering unit to control the differential pressurization of the second pump. As the bypass is reduced, the pressure of the second pump is increased so that it may be added to that of the first pump to supply the increased fuel consumption needs of an engine. As the fuel consumption needs decrease, the flow from the second pump added to the first pump is reduced and the differential pressure of the second pump is similarly reduced. If the bypass pressure remains high, the switching system disconnects the output of the second pump from that of the first in favor of bypassing the flow to its input to reduce its differential pressure and conserve energy.

Abstract: A fuel split control arrangement is provided. The arrangement includes a staged cooling flow control valve and cooling check valve. The staged cooling flow control valve and cooling check valve is connected between the primary and secondary tips of a nozzle in a turbine engine. The staged cooling flow control valve and cooling check valve includes a valve member arrangement operable to prevent fuel flow from the secondary fuel supply manifold to the secondary tip and simultaneously allow fuel flow from the secondary fuel supply manifold to the primary tip such that the primary tip receives fuel flow from both the secondary fuel supply manifold and the primary fuel supply manifold.