Patent Description:
Bleed systems are used to extract pressurized air from turbine engines for various uses, including supplying auxiliary power, cooling air, and other air loads served by the system. For example, aircraft bleed systems may extract pressurized air from a turbine engine supplying thrust to the aircraft to provide air to various air loads and air-use systems, such as to an environmental control system configured to pressurize a cabin of the aircraft, an air drive unit configured to pressurize hydraulics, an anti-icing system configured to remove and/or limit ice on a wing of the aircraft, an inert gas generating system configured to pressurize a fuel tank of the aircraft, and other air loads The bleed system provides the bleed air at a pressure, temperature, and mass flow sufficient to ensure an adequate bleed air supply to the served loads.

<CIT> discloses a bleed air system selectively supplies engine bleed air from one or more of at least three bleed air sources to a variable geometry ejector pump. <CIT> discloses a pneumatic flow-control system and method for an aircraft provide efficient mixing of high-pressure engine bleed air with one or both of low-pressure engine bleed air and ambient air. <CIT> discloses a fluid flow delivery system and, more particularly, to the means for controlling the pressurized fluid flow from two or more sources; wherein, the fluid pressure from one of the sources is higher relative to the other. <CIT> discloses a system for controlling the flow of air to an enclosure from a plurality of sources of different pressures, such as high- and low-pressure stages of the compressor of an aircraft engine. <CIT> discloses a mixing valve mixing a primary and secondary pressure bleed air supply. <CIT> discloses a first circuit that selects between a first bleed air supply having a first pressure and a second bleed air supply having a second pressure that is greater than the first pressure to render a first buffer supply air having an intermediate pressure. <CIT> discloses an ejector comprising a mixing section. <CIT> discloses a system and method of using a variable geometry ejector for a bleed air system using integral bleed pressure feedback which utilizes a minimal amount of high-pressure air.

The present disclosure describes a bleed system (also referred to herein as a bleed air system) according to claim <NUM>.

Turbine engines (e.g., gas turbines) generally intake and compress a gas such as air in a compressor section prior using the gas to combust fuel for engine thrust. The compressor section generally receives the gas (e.g., air) through an intake and compresses the gas using a series of compressor stages. The compressor stages progressively increase the gas pressure, in order to provide the gas in sufficient quantity and pressure to a combustion section. The combustion section mixes the gas and a fuel and causes a combustion. The combustion generates rapidly expanding combustion gases which may be utilized to rotate a turbine shaft and/or produce engine thrust. In aircraft engines, in addition to causing some amount of shaft rotation to drive the compressor section, the combustion gases are ejected through an exhaust section to generate engine thrust for the aircraft.

In some cases, a portion of the compressed gas is diverted from the compressor section of the turbine engine as a bleed gas (e.g., bleed air) prior to entering the combustion section. The bleed gas may be extracted from the compressor section and provided to a bleed system configured to distribute the bleed gas to various gas loads (also referred to as air loads in some examples) operating elsewhere in the system. For example, bleed gas may be extracted from one or more compressor stages of a turbine engine during aircraft flight to support applications such as one or more of an Environmental Control System (ECS) system of a passenger cabin, wing anti-icing, air-driven motors, hydraulic pressurization, fuel tank pressurization, or other uses. The bleed system may use a network of ducts, valves, regulators, and other components to route the bleed gas from the compressor section of the turbine engine to various locations within the aircraft. The bleed system is typically configured to extract sufficient bleed gas from the turbine engine to substantially maintain the air pressure in the distribution system within a specific pressure range.

In some bleed air systems, bleed gas is extracted from multiple compressor stages of the turbine engine in order to provide sufficient gas to the one or more gas loads served. For example, the bleed system may be configured to extract a relatively low pressure air ("lower pressure air") from an initial compressor stage and a relatively high pressure air ("higher pressure air") from a subsequent compressor stage. The lower pressure air has a lower pressure than the higher pressure air. For example, the lower pressure gas may be intermediate pressure air ("IP air") from an intermediate compressor stage of a turbine engine and the higher pressure gas may be high pressure air ("HP air") from a high compressor stage of the turbine engine. The higher pressure gas extracted from the subsequent compressor stage generally has a higher pressure and temperature than the lower pressure gas air extracted from the initial compressor stage. As a non-limiting example, in the context of some aircraft, the higher pressure gas may be at about <NUM> Atmospheres (about <NUM> pounds per square inch (psi)) and a temperature of <NUM>-<NUM> degrees Fahrenheit (about <NUM>-<NUM> degrees Celsius) and the lower pressure gas may be at <NUM>-<NUM> degrees Fahrenheit (about <NUM>-<NUM> degrees Celsius).

The bleed system may be configured to mix the higher pressure gas and the lower pressure gas in order to maintain the gas supply to the operating loads. For example, in some bleed systems, when the lower pressure gas (e.g., the IP air) extracted is insufficient to meet the operating requirements of the served gas loads (e.g., at lower engine power), the bleed system may be configured to extract and mix the higher pressure gas (e.g., the HP air) with the lower pressure gas to maintain a sufficient gas supply to the gas loads.

In some examples, the bleed system is configured to adjust the relative amounts of higher pressure gas and lower pressure gas extracted by monitoring a control variable, such as a pressure and/or temperature of the mixed gas within the bleed system. The control variable may be sensed by sensors positioned at one or more specific fixed locations in the bleed system, such as a point upstream of the gas loads being served by the bleed system. The control circuitry of the bleed system may adjust the relative amounts of higher pressure gas and lower pressure gas extracted based on a comparison between the monitored control variable and a system setpoint. In this manner, the bleed system may use the control variable as a proxy for system demand. However, in bleed systems serving multiple gas loads with individual mixed gas requirements, a single and/or unvarying system setpoint for the monitored control variable may be inadequate to accurately reflect the system demand as the individual gas loads are transiently operated (e.g., are turned on or off, or experience increased or decreased output load). This may result in extracting more higher pressure gas from the turbine engine than might be required based on the actual demands of the individual loads. This excess use of the higher pressure gas may detract from the achievable fuel efficiency of the turbine engine. That is, because the bleed air is generally extracted after compression by the turbine engine, bleed air use may result in additional fuel consumption by the turbine engine. Hence, the fuel efficiency of the turbine engine may be impacted by the bleed system.

The bleed system disclosed herein is configured to adjust an amount of the higher pressure gas and the lower pressure gas extracted by at least comparing a fluid parameter (e.g., a pressure, a temperature, and/or flow rate) within the bleed system to a system setpoint using control circuitry. The control circuitry is configured to receive a signal indicative of the fluid parameter and compare the indicated fluid parameter to a set point. The control circuitry may be configured to establish the system setpoint based on reception of a communication signal, such that the system setpoint may be varied. The control circuitry is configured to cause a jet pump of the bleed system to alter a mixing ratio of the higher pressure gas to the lower pressure gas based on a comparison of the fluid parameter indicated and the established system setpoint. In examples, the control circuitry is configured to establish the system setpoint based on individual gas loads operating within the bleed system at a given time. Hence, the bleed system may be configured to substantially maintain the fluid parameter based on a variable system setpoint, where the variable system setpoint is determined based on the individual gas loads currently operating in the bleed system. This may reduce an amount of higher pressure gas extracted from the compressor section and limit the impact of the extraction on turbine engine efficiency.

The bleed system disclosed herein is configured to receive a lower pressure gas and a higher pressure gas from a turbine engine. The lower pressure gas may be air, such as an IP air. The higher pressure gas may be air, such as HP air. The turbine engine may be configured to intake the gas (e.g., air) through an intake and compress the gas using one or more compressor stages. The turbine engine may be configured to provide some portion of the compressed gas as the lower pressure gas and the higher pressure gas. For example, the turbine engine may be configured to provide the lower pressure gas from a lower pressure stage in a compressor section of the turbine engine (e.g., the third compressor stage) and provide the higher pressure gas from a higher pressure stage in the compressor section of the turbine engine (e.g., the seventh compressor stage). In examples, the turbine engine is configured to provide another portion of the compressed gas to a combustion chamber for use as an oxidant to enable the combustion of a fuel.

The bleed system is configured to combine the lower pressure gas and the higher pressure gas received to produce a mixed gas. The bleed system is configured to provide the mixed gas to one or more gas loads configured to receive the mixed gas. For example, when the mixed gas is air, the bleed system may be configured to provide the mixed gas to an Environmental Control System (ECS) configured to cool and/or pressurize a cabin of an aircraft. As another example, in addition to or instead of the ECS, the bleed system may be configured to provide the mixed gas to one or more air driven motors such as an Air Drive Unit (ADU) configured to pressurize hydraulics, an aircraft wing anti-icing system configured to remove and/or limit ice on an aircraft wing, an inert gas generating system configured to pressurize a fuel tank, and other gas loads. The bleed system may be configured to provide the mixed gas to any pneumatic system configured to receive a gas. The pneumatic system may be a system configured to support the operations of aircraft.

The bleed system includes a jet pump configured to receive the lower pressure gas and higher pressure gas. The jet pump is configured to mix the lower pressure gas and the higher pressure gas to produce a mixed gas. The jet pump may be configured to supply the mixed gas to a gas supply header configured to provide the gas to gas loads served by the bleed system. The jet pump may be configured to vary a mixing ratio of the higher pressure gas to the lower pressure gas when the jet pump produces the mixed gas. In examples, the jet pump is a variable nozzle jet pump. In some examples, the jet pump includes a variable nozzle configured having translating member (e.g., a needle) configured to translate relative to a nozzle body to increase or decrease a flow area defined between the translating member and the nozzle body. The jet pump may be configured to translate the translating member to increase or decrease the flow area in order to vary the mixing ratio of the higher pressure gas to the lower pressure gas combined to produce the mixed gas.

This variable nozzle jet pump may be configured to enable elimination of a jet pump bypass valve, which is typically required to reduce flow restrictions and pressure losses associated with operation at low engine throttle from the HP air source.

The control circuitry of the bleed system is configured to cause the jet pump to alter the mixing ratio of the higher pressure gas to the lower pressure gas based on a fluid parameter (e.g., a pressure, a temperature, and/or a flow rate) of the mixed gas in the bleed system. For example, in some examples, the control circuitry is configured to receive one or more signals (e.g., an electronic, optical, or other signal) indicative of the one or more fluid parameters from one or more sensors within the bleed system and cause the jet pump to alter the mixing ratio based on the signals. In examples, the control circuitry is configured to compare the fluid parameter indicated by the sensor with a system setpoint and cause the jet pump to alter the mixing ratio based on the comparison. The jet pump may be configured to cause the jet pump to alter the mixing ratio (e.g., increase or decrease the ratio of the higher pressure gas to the lower pressure gas) in order to reduce and/or eliminate a departure between the indicated fluid parameter and the set point. Thus, the bleed system may be configured to configured to substantially maintain the fluid parameter based on a variable system setpoint, potentially limiting the impact of the higher pressure gas extraction on the efficiency of a turbine engine providing the higher pressure gas. The bleed system may limit the impact of one or more loads such as an ECS, an ADU, an anti-icing system, and/or a fuel pressurizing system of the fuel consumption of a turbine engine. In examples, the bleed system may reduce a size and/or weight requirement associated with a pre-cooler ("PCL") configured to cool a gas within the bleed system.

The control circuitry can determine the system setpoint using any suitable technique. In some examples, the control circuitry determines the system setpoint by at least referencing a system setpoint stored by a memory accessible to the control circuitry. The control circuitry is configured to receive a load signal (e.g., one or more electronic communications) and establish the set point based on the load signal, such that the system setpoint may be varied and vary over time.

In some examples, the control circuitry is configured to determine the system setpoint based on a current and/or anticipated demand for the mixed gas based on an operating status of one or more of the gas loads within the bleed system. For example, the control circuitry may be configured to receive one or more load signals indicating the operating status of the one or more gas loads and establish the system setpoint based on the load signals. The load signal may be a binary on/off signal indicating whether a specific gas load is operating or secured, a signal indicative of an amount of mixed gas the specific gas load is using or anticipated to use, or some other signal type indicating use of the mixed gas by the specific gas load. Hence, the control circuitry may be configured to establish the system setpoint based on the mixed gas demand of the operating gas loads within the bleed system, such that the jet pump adjusts the amount of the higher pressure gas extracted based on the operational needs of the currently operating gas loads.

<FIG> illustrates an example bleed system <NUM> configured to receive a lower pressure gas and a higher pressure gas from a turbine engine <NUM> of an aircraft <NUM>. While aircraft <NUM> is primarily referred to in the description of <FIG> and some of the other figures, bleed system <NUM> and other bleed systems described herein may be part of another vehicle or another non-vehicle system that includes gas loads configured to receive bleed air.

Turbine engine <NUM> includes a turbine engine fan section <NUM>, a compressor section <NUM>, a combustion section <NUM>, and an exhaust section <NUM>. Turbine engine <NUM> is configured to receive a gas flow (e.g., an air flow) via turbine engine fan section <NUM> and compress the gas in compressor section <NUM> using a series of compressor stages to progressively increase the gas pressure. Turbine engine <NUM> mixes a portion (e.g., a majority) of the compressed gas and a fuel in a combustion section <NUM> to cause a combustion and generate combustion gases. The combustion gases eject through an exhaust section <NUM> to generate engine thrust for aircraft <NUM>. Aircraft <NUM> may include any number of engines such as turbine engine <NUM> configured to generate engine thrust on aircraft <NUM>.

Bleed system <NUM> is configured to divert some amount of the compressed gas from compressor section <NUM> prior to the compressed gas entering combustion section <NUM>. Bleed system <NUM> may be configured to extract the compressed gas from multiple compressor stages of compressor section <NUM> of turbine engine <NUM>. For example, bleed system <NUM> may extract a lower pressure air from a lower pressure compressor stage of compressor section <NUM> through a conduit <NUM> fluidly coupled to the lower pressure compressor stage and a higher pressure air from a higher pressure compressor stage of compressor section <NUM> through a conduit <NUM> fluidly coupled to the higher pressure compressor stage. In some examples, the lower pressure gas is IP air from an intermediate compressor stage of turbine engine <NUM> and the higher pressure gas is HP air from a high compressor stage of turbine engine <NUM>. In other examples, however, the lower pressure gas is air from a different compressor stage of turbine engine <NUM> and/or the higher pressure gas is air from a different compressor stage, but is still at a higher pressure than the lower pressure gas.

Bleed system <NUM> includes a jet pump <NUM> is configured receive the lower pressure gas via conduit <NUM> and the higher pressure gas via conduit <NUM>. Jet pump <NUM> is configured to combine the higher pressure gas and the lower pressure gas to produce a mixed gas. Jet pump <NUM> is configured to combine the lower pressure gas and the higher pressure gas in a mixing ratio, where the mixing ratio reflects a ratio of the higher pressure gas to the lower pressure gas combined when jet pump <NUM> produces the mixed gas. Jet pump <NUM> is further configured to alter the mixing ratio. In examples, jet pump <NUM> includes a translating member configured to translate to alter the mixing ratio. For example, jet pump <NUM> may be a variable nozzle jet pump including a translating member (e.g., a needle) configured to translate relative to a nozzle body of jet pump <NUM> to increase or decrease a flow area for the higher pressure gas or the lower pressure gas. Jet pump <NUM> may be configured to translate the translating member to increase or decrease the flow area in order to vary the mixing ratio of the higher pressure gas to the lower pressure gas combined to produce the mixed gas.

The use of a variable nozzle jet pump such as jet pump <NUM> configured to alter the mixing ratio by altering a flow area of the variable nozzle may enable control of a fluid parameter (e.g., a pressure) within the bleed system over a greater range and/or in a more responsive manner than that which might be achieved using a fixed nozzle jet pump. For example, a fixed nozzle jet pump system may be more limited in the maximum or minimum values of the fluid parameter the fixed nozzle may achieve by mixing the higher pressure gas and the lower pressure gas as compared to a variable nozzle jet pump. The fixed nozzle jet pump may further be reliant on other components within the bleed system to increase or decrease a flow rate of the higher pressure gas and/or lower pressure gas to alter the mixing ratio, possibly resulting in a decreased responsiveness of the system.

Bleed system <NUM> includes control circuitry <NUM> configured to cause jet pump <NUM> to alter the mixing ratio. Control circuitry <NUM> is configured to receive a signal (e.g., an electrical signal or an optical signal) indicative of a fluid parameter of the mixed gas (e.g., a pressure, temperature, and/or flow rate) from a sensor <NUM> and compare the indicated fluid parameter to a system setpoint. Control circuitry <NUM> may be configured to receive the signal via a communication link <NUM>. Control circuitry <NUM> is configured to cause jet pump <NUM> to alter the mixing ratio based on the comparison of the indicated fluid parameter indicated and the system setpoint. For example, if the fluid parameter indicated by sensor <NUM> is less than a system setpoint, then control circuitry <NUM> may cause jet pump <NUM> to alter the mixing ratio such that the fluid parameter within supply conduit <NUM> increases to substantially match (e.g., match or get closer to, such as within <NUM>% - <NUM>% of) the system setpoint. If the fluid parameter indicated by sensor <NUM> is greater than a system setpoint, then control circuitry <NUM> may cause jet pump <NUM> to alter the mixing ratio such that the fluid parameter within supply conduit <NUM> decreases to substantially match the system setpoint. In examples, the system setpoint is defined by a range of values around a central setpoint value, and the fluid parameter within supply conduit <NUM> substantially matches the system setpoint when the fluid parameter is within the range of values. In examples, control circuitry <NUM> is configured to transmit a control signal to cause jet pump <NUM> to alter the mixing ratio via a communication link <NUM>.

In some examples, bleed system <NUM> includes a pre-cooler <NUM> ("PCL <NUM>") configured to exchange heat with (e.g., cool) the mixed gas issued from jet pump <NUM> to supply conduit <NUM>. For example PCL <NUM> may be configured to cool the mixed gas from a temperature greater than about <NUM>°F (<NUM>) to temperature less than about <NUM>°F (<NUM>). PCL <NUM> may be configured to receive a gas flow via conduit <NUM> and may be configured to cause heat exchange between the gas flow and the mixed gas in PCL <NUM>. In examples, conduit <NUM> is fluidly coupled to turbine engine fan section <NUM> of turbine engine <NUM>, and bleed system <NUM> is configured to supply the gas flow to PCL <NUM> from the turbine engine fan section <NUM>. The gas flow received via conduit <NUM> may be relatively low pressure air ("fan air") from turbine engine fan section <NUM>. PCL <NUM> may be configured to discharge the gas flow via discharge conduit <NUM> following the heat exchange with the mixed gas. In examples, bleed system <NUM> is configured to discharge the gas flow overboard or into the engine core compartment of aircraft <NUM> via discharge conduit <NUM>.

Bleed system <NUM> may include a filtration unit <NUM> configured to condition at least some portion of the mixed gas. In examples, filtration unit <NUM> is configured to reduce an ozone concentration within the mixed gas by, for example, converting some portion of the ozone (O3) in the mixed gas to diatomic oxygen (O2). Filtration unit <NUM> may be configured to remove substances such as hydrocarbons, water, and/or particulates from the mixed gas. Although illustrated in <FIG> located downstream of jet pump <NUM> and PCL <NUM>, filtration unit <NUM>, if present, may be located in any suitable place within bleed system <NUM>. For example, filtration unit <NUM> may be located downstream of jet pump <NUM> and upstream of PCL <NUM> (e.g., between jet pump <NUM> and PCL <NUM>), or elsewhere within bleed system <NUM>.

Bleed system <NUM> is configured to distribute the mixed gas from supply conduit <NUM> to one or more gas loads <NUM> of aircraft <NUM>, such as environmental control system <NUM> ("ECS <NUM>"), fuel tank system <NUM>, air drive unit <NUM> ("ADU <NUM>"), and/or anti-icing system <NUM>. ECS <NUM> may be configured to further condition a first portion of the mixed gas prior to utilizing the first portion to pressurize a cabin of aircraft <NUM>. Fuel tank system <NUM> may be configured to utilize a second portion of the mixed gas (e.g., a nitrogen-enriched portion) to pressurize an ullage space of fuel tank system <NUM>. Bleed system <NUM> may include an inert gas generation system <NUM> configured to reduce an oxygen concentration of the second portion prior to the second portion entering the ullage space of a fuel tank within fuel tank system <NUM>. ADU <NUM> may be a gas-driven motor configured to utilize a third portion of the mixed gas to pressurize a hydraulic system of aircraft <NUM> to allow, for example, the operation of flaps and other control surfaces of aircraft <NUM>. Anti-icing system <NUM> may be configured to utilize a fourth portion of the mixed gas to remove and/or limit ice on a wing or other portion of aircraft <NUM>. Bleed system <NUM> may be configured to provide the mixed gas to a pneumatic system <NUM> of aircraft <NUM> instead of or in addition to ECS <NUM>, fuel tank system <NUM>, ADU <NUM>, or anti-icing system <NUM>. Pneumatic system <NUM> may be a system, device, component, or combination thereof configured to receive mixed gas from a gas source such as bleed system <NUM>. In examples, pneumatic system <NUM> is a system, device, component, or combination thereof configured to support the operations of aircraft <NUM>.

As discussed, control circuitry <NUM> is configured to receive a signal indicative of a fluid parameter of the mixed gas from sensor <NUM>. The signal may be an electronic signal, an optical signal, or another signal sufficient to provide information describing the fluid parameter from sensor <NUM> to control circuitry <NUM>. Sensor <NUM> is configured to monitor the fluid parameter of the mixed gas within supply conduit <NUM>. Jet pump <NUM> is configured to produce the mixed gas by at least combining the higher pressure gas received via conduit <NUM> and the lower pressure gas received via conduit <NUM>. Control circuitry <NUM> is configured to cause jet pump <NUM> to alter a mixing ratio of the higher pressure gas to the low pressure gas used to produce the mixed gas based on the signal received from sensor <NUM>. In examples, control circuitry <NUM> compares the fluid parameter indicated by the signal from sensor <NUM> to a system setpoint, and causes jet pump <NUM> to alter the mixing ratio based on the comparison.

The demand for the mixed gas by gas loads <NUM> may impact the fluid parameter of the mixed gas within supply conduit <NUM>. For example, when the fluid parameter is a pressure and sensor <NUM> is configured to indicate a pressure of the mixed gas in supply conduit <NUM>, an increased demand for the mixed gas (e.g., an increased mass flow) to ECS <NUM>, fuel tank system <NUM>, ADU <NUM>, anti-icing system <NUM>, and/or another gas load served by bleed system <NUM> may cause a decrease in the pressure of the mixed gas in supply conduit <NUM>. The decrease in pressure may cause sensor <NUM> to provide a signal to control circuitry <NUM> indicative of the reduced pressure. In response to the signal, control circuitry <NUM> may cause jet pump <NUM> to alter the mixing ratio of the higher pressure gas to the lower pressure gas to cause the pressure of the mixed gas in supply conduit <NUM> to increase. For example, control circuitry <NUM> may cause jet pump <NUM> to increase a flow area to increase a flow of the higher pressure gas received via conduit <NUM>.

Similarly, a decreased demand for the mixed gas to ECS <NUM>, fuel tank system <NUM>, ADU <NUM>, anti-icing system <NUM>, and/or another gas load served by bleed system <NUM> may cause an increase in the pressure of the mixed gas in supply conduit <NUM>, causing sensor <NUM> to provide a signal indicative of the increased pressure, such that control circuitry <NUM> causes jet pump <NUM> to alter the mixing ratio to cause the pressure of the mixed gas in supply conduit <NUM> to decrease. Control circuitry <NUM> may compare the fluid parameter indicated by the signal from sensor <NUM> to a system setpoint, such that control circuitry <NUM> causes jet pump <NUM> to alter the mixing ratio until jet pump <NUM> achieves a mixing ratio causing the fluid parameter indicated to better match (e.g., substantially match) the system setpoint.

In examples, bleed system <NUM> and/or gas loads <NUM> may be configured such that the individual demand for mixed gas from an individual gas load is satisfied by a value of the fluid parameter within supply conduit <NUM> different from a value of the fluid parameter required by one or more other gas loads within gas loads <NUM>. For example, bleed system <NUM> and/or gas loads <NUM> may be configured such that the demand for mixed gas from a first gas load (e.g., ECS <NUM>) is satisfied by a first value of the fluid parameter of the mixed gas within supply conduit <NUM> (e.g., satisfied by a first pressure). Bleed system <NUM> and/or gas loads <NUM> may be configured such that the demand for mixed gas from a second gas load (e.g., fuel tank system <NUM>) is satisfied by a second value of the fluid parameter within supply conduit <NUM> (e.g., satisfied by a second pressure). The first value may be different from the second value. Similarly, a third gas load (e.g., ADU <NUM>) may require a third value different from the first value and/or the second value, and a fourth gas load (e.g., anti-icing system <NUM>) may require a fourth value different from the first value, the second value, and/or the third value. Similarly, different operating combinations among the first gas load, the second gas load, the third gas load, and/or the fourth gas load may require differing values of the fluid parameter within supply conduit <NUM> to satisfy the combined gas demand of the operating gas loads. Hence, providing a mixed gas based on a single, unvarying system setpoint may result in extracting more higher pressure gas from turbine engine <NUM> than might actually be required based on the combined gas demand of the operating gas loads. This excess use of the higher pressure gas may reduce the fuel efficiency (e.g., may increase the thrust-specific fuel consumption (TFSC)) achieved during operation of turbine engine <NUM>.

Control circuitry <NUM> is configured to determine the system setpoint for bleed system <NUM> using any suitable technique. In some example, the system setpoint is determined by other control circuitry and transmitted to control circuitry <NUM>. In addition or instead, in some examples, control circuitry <NUM> is configured to establish the system setpoint for bleed system <NUM>. For example, control circuitry <NUM> may be configured to establish the system setpoint based on an operating status of one or more of gas loads <NUM>. In examples, control circuitry <NUM> is configured to receive a load signal indicative of an operating status of the one or more of gas loads <NUM> and determine the system setpoint based on the load signal. The load signal may be, for example, a binary on/off signal indicating whether a gas load within gas loads <NUM> is operating or secured, a signal indicative of an amount of mixed gas the gas load within gas loads <NUM> is using or anticipated to use, or some other signal type indicating use of the mixed gas by the gas load within gas loads <NUM>. In examples, control circuitry <NUM> is configured to receive a plurality of load signals from a plurality of gas loads within gas loads <NUM> and establish the system setpoint based on the plurality. For example, control circuitry <NUM> may be configured to receive a first signal from a first gas load (e.g., ECS <NUM>), a second signal from a second gas load (e.g., fuel tank system <NUM>), a third signal from a third gas load (e.g., ADU <NUM>), and/or a fourth signal from a fourth gas load (e.g., anti-icing system <NUM>). Control circuitry <NUM> may be configured to ascertain a combination of gas loads currently operating within bleed system <NUM> based the first signal, the second signal, the third signal, and/or the fourth signal. Control circuitry <NUM> may be configured to establish the system setpoint based on the ascertained combination. Jet pump <NUM> may alter a mixing ratio of the higher pressure gas to the lower pressure gas to meet the system setpoint established by control circuitry <NUM>, such that jet pump <NUM> extracts an amount of higher pressure gas from turbine engine <NUM> based on the combined gas demand of the ascertained combination of gas loads.

<FIG> illustrates an example bleed system <NUM> including jet pump <NUM> and one or more gas loads <NUM>. Jet pump <NUM> is configured to extract a lower pressure gas via conduit <NUM> and a higher pressure gas via conduit <NUM> from turbine engine <NUM>. Jet pump <NUM> is configured to provide a mixed gas to supply conduit <NUM> for used by one or more gas loads <NUM>, such as ECS <NUM>, fuel tank system <NUM>, ADU <NUM>, anti-icing system <NUM>, and/or pneumatic system <NUM>. Control circuitry <NUM> is configured to receive a signal indicative of a fluid parameter of the mixed gas from sensor <NUM> and cause jet pump <NUM> to vary a mixing ratio of the higher pressure gas to the lower pressure gas extracted based on the signal.

Bleed system <NUM> may be configured for use on an aircraft, such as aircraft <NUM> (<FIG>). Bleed system <NUM> may include additional valves, sensors, and other equipment at various locations within bleed system <NUM>. For example, bleed system <NUM> may include one or more of an intermediate pressure check valve <NUM> ("IPCV") configured to allow a flow of lower pressure gas through conduit <NUM>, a high pressure valve <NUM> ("HPV") configured to allow a flow of higher pressure gas through conduit <NUM>, a jet pump bypass valve <NUM> ("JPBPV") configured to bypass a portion of the higher pressure gas around jet pump <NUM>, a mid-pressure valve <NUM> ("MPV") and/or over pressure shut off valve <NUM> ("OPSOV") configured to allow a flow of mixed gas in supply conduit <NUM>, a fan air valve <NUM> ("FAV") configured to allow a flow of gas (e.g., air) from turbine engine fan section <NUM> via conduit <NUM> to PCL <NUM>, starter valve <NUM> configured to allow a flow of mixed gas to turbine engine <NUM>, flow control valve <NUM> ("FCV") configured to control a flow of the mixed gas to ECS <NUM>, and valve <NUM>, valve <NUM>, valve <NUM>, and valve <NUM> configured to control a flow of mixed gas to fuel tank system <NUM>, ADU <NUM>, anti-icing system <NUM>, and pneumatic system <NUM> respectively.

Bleed system <NUM> may include one or more of bleed temperature sensor <NUM> ("TB") and/or manifold temperature sensor <NUM> ("TM") configured to sense a temperature of the mixed gas in supply conduit <NUM>, and first manifold pressure sensor <NUM> ("PM1") and/or second manifold pressure sensor <NUM> ("PM2") configured to sense a pressure of the mixed gas in supply conduit <NUM>. Bleed system <NUM> may include other valves, sensors, and/or control equipment configured to control a flow of gas through bleed system <NUM>.

In some examples, control circuitry <NUM> is configured to compare the signal received from sensor <NUM> to a system setpoint and cause jet pump <NUM> to alter the mixing ratio of the higher pressure gas received via conduit <NUM> to the lower pressure gas received via conduit <NUM> based on the comparison. In examples, control circuitry <NUM> is configured to receive the system setpoint by at least referencing a system setpoint stored by a memory accessible to the control circuitry. Control circuitry <NUM> may receive the system setpoint via, for example, communication link <NUM>. The system setpoint received by control circuitry <NUM> may be variable. For example, control circuitry <NUM> may receive a first setpoint via communication link <NUM> and cause jet pump <NUM> to alter the mixing ratio such that the fluid parameter sensed by sensor <NUM> substantially matches and/or satisfies the system setpoint. Control circuitry <NUM> may subsequently receive a second setpoint different from the first setpoint via communication link <NUM> and cause jet pump <NUM> to alter the mixing ratio such that the fluid parameter sensed by sensor <NUM> substantially matches and/or satisfies the second setpoint. Hence, control circuitry <NUM> may be configured to cause jet pump <NUM> to adjust the higher pressure gas and lower pressure gas extracted to substantially match a variable system setpoint. The ability of control circuitry <NUM> to cause jet pump <NUM> to respond to a variable setpoint may reduce the amount of higher pressure gas extracted and limit impacts on turbine engine efficiency as compared to bleed systems configured to operate with a substantially constant and invariable system setpoint.

In some examples, control circuitry <NUM> may be configured to establish the system setpoint based on one or more load signals indicative of an operating status and/or anticipated gas demand of one or more gas loads <NUM> within bleed system <NUM>. For example, ECS <NUM> may be configured to utilize a portion of the mixed gas generated by jet pump <NUM> as a coolant for one or more air packs supplying air to an aircraft cabin. Control circuitry <NUM> may be configured to receive a first load signal indicative of (e.g., which changes as a function of) the quantity of the air packs operating or anticipated to operate within ECS <NUM> via communication link <NUM>. Fuel tank system <NUM> may be configured to utilize a portion of the mixed gas generated by jet pump <NUM> to pressurize an ullage space of a fuel tank as aircraft <NUM> consumes fuel. Control circuitry <NUM> may be configured to receive a second load signal indicative of a demand for fuel tank pressurization by fuel tank system <NUM> via communication link <NUM>.

ADU <NUM> may be configured to utilize a portion of the mixed gas generated by jet pump <NUM> to drive a gas driven motor configured to pressurize a hydraulic system for operation of control surfaces and/or landing gear of aircraft <NUM>. Control circuitry <NUM> may be configured to receive a third load signal indicative of a demand by the gas driven motor to substantially maintain the hydraulic system pressure as control surfaces are operated via communication link <NUM>. Anti-icing system <NUM> may be configured to utilize a portion of the mixed gas generated by jet pump <NUM> to remove ice or other substances from a wing or other portion of aircraft <NUM>. Control circuitry <NUM> may be configured to receive a fourth load signal indicative of a demand for anti-icing by anti-icing system <NUM> via communication link <NUM>. In examples, control circuitry <NUM> may be configured to receive one or more additional load signals indicative of a demand for mixed gas by pneumatic system <NUM> via communication link <NUM>. Control circuitry <NUM> may establish the system setpoint for bleed system <NUM> based on the load signals received, in order to minimize and/ or eliminate an extraction of higher pressure air from turbine engine <NUM> in excess of that required for satisfactory operation of the gas loads <NUM>.

A gas load (e.g., one or more of the gas loads <NUM>) may be configured to generate the load signal based on the demand and/or anticipated demand for the mixed gas by the gas load. The gas load may be configured to transmit the load signal to control circuitry <NUM>. In examples, some portion of or substantially all of control circuitry <NUM> may be housed and/or mechanically supported within a controller housing configured to be located adjacent to jet pump <NUM> or another portion of bleed system <NUM>. In some examples, control circuitry <NUM> is housed and/or mechanically supported by housings of one or more of gas loads <NUM> and/or one or more other housings within aircraft <NUM>.

Control circuitry <NUM> may be configured to interpret any load signals (e.g., load signals received via communication links <NUM>, <NUM>, <NUM>, <NUM>) representing a demand for mixed gas from one or more of gas loads <NUM>. For example, control circuitry <NUM> may be configured to interpret a load signal indicating demand by indicating whether a gas load is in an operating state consuming and/or anticipated to consume mixed gas or in a secured state wherein a mixed gas demand from the load is substantially negligible and/or absent. Control circuitry <NUM> may be configured to interpret a load signal indicating demand by indicating a specific and/or anticipated operating configuration of a gas load, such as a number of subsystems (e.g., air packs within ECS <NUM>) operating/ and/or anticipated to operate in the gas load. Control circuitry <NUM> may be configured to receive a load signal from one or more subsystems within an air load configured to operate when the gas load consumes the mixed gas. In examples, control circuitry <NUM> is configured to interpret load signals indicating a quantity of mixed gas consumed by an air load. For example, a portion of bleed system <NUM> such as a portion including flow control valve <NUM>, valve <NUM>, valve <NUM>, or valve <NUM> may be configured to sense a mass flow or other parameter of mixed gas flowing through the bleed system portion and provide a load signal to control circuitry <NUM> based on the mass flow or other parameter. In examples, one or more gas loads <NUM> is configured to sense a mass flow or other parameter of mixed gas an provide the load signal to control circuitry <NUM> based on the mass flow or other parameter.

Sensor <NUM> may be configured to sense the fluid parameter of the mixed gas at any suitable location within bleed system <NUM>. In some examples, sensor <NUM> is configured to sense the fluid parameter at a location within bleed system <NUM> downstream of jet pump <NUM> and upstream of the one or more gas loads <NUM>. For example , sensor <NUM> may be configured to sense the fluid parameter downstream of jet pump <NUM> and upstream of PCL <NUM>. Here, "downstream" connotes a flow direction of a mixed gas from jet pump <NUM> and to the one or more gas loads <NUM> and/or PCL <NUM>. "Upstream" connotes a flow direction opposite the downstream direction. Sensor <NUM> may be located upstream or downstream of other sensors and or components within bleed system <NUM>, such as intermediate pressure check valve <NUM>, high pressure valve <NUM>, jet pump bypass valve <NUM>, mid-pressure valve <NUM>, over pressure shutoff valve <NUM>, fan air valve <NUM>, flow control valve <NUM>, valve <NUM>, valve <NUM>, valve <NUM>, starter valve <NUM>, bleed temperature sensor <NUM>, manifold temperature sensor <NUM>, first manifold pressure sensor <NUM>, and/or second manifold pressure sensor <NUM>.

In some examples, control circuitry <NUM> is configured to receive signals indicative of a fluid parameter from additional sensors within bleed system <NUM> in addition to sensor <NUM>. For example, control circuitry <NUM> may be configured to receive one or more signals indicative of a fluid parameter from bleed temperature sensor <NUM>, first manifold pressure sensor <NUM>, manifold temperature sensor <NUM>, second manifold pressure sensor <NUM>, and other sensors configured to sense a fluid parameter of the mixed gas within bleed system <NUM>. The additional sensors may be configured to sense the same type of fluid parameter as sensor <NUM>, or may be configured to sense a type of fluid parameter different from that sensed by sensor <NUM>. For example, control circuitry <NUM> may be configured to receive a first signal from sensor <NUM> indicative of a pressure of the mixed gas and receive one or more additional signals indicative of a temperature, flow rate, or other fluid parameter of the mixed gas. In these examples, control circuitry <NUM> is configured to cause jet pump <NUM> to alter a mixing ratio of the higher pressure gas received via conduit <NUM> and the lower pressure gas received via conduit <NUM> based on the first signal and the one or more additional signals.

Turbine engine <NUM> may be configured to receive a gas (e.g., air) from turbine engine fan section <NUM> and progressively increase the pressure of the gas through a series of successive compressor stages. Turbine engine <NUM> may be configured such that a first compressor stage compresses the gas to a first pressure, a second compressor stage receives the gas from the first compressor stage and increases the pressure to a second pressure greater than the first pressure, a third compressor stage receives the gas from the second compressor stage and increases the pressure to a third pressure greater than the second pressure, and so on until turbine engine <NUM> issues the gas from a final compressor stage to combustion section <NUM>. In some examples, bleed system <NUM> is configured to extract higher pressure gas via conduit <NUM> from a compressor stage outside of the last <NUM>% of the compressor stages of turbine engine <NUM>. For example, turbine engine <NUM> may include a plurality of compressor stages designated one through ten, with the tenth compressor stage configured to issue compressed gas to combustion section <NUM>, such that the <NUM>% of the compressor stages includes compressor stage nine and compressor stage ten.

In some examples, turbine engine <NUM> is configured to increase a pressure of a gas stream as the gas stream flows from an initial compressor stage to a penultimate compressor stage to a final compressor stage, wherein the penultimate compressor stage is configured to issue the compressed gas to the final compressor stage and the final compressor stage is configured to issue the compressed gas to combustion section <NUM>. Bleed system <NUM> may be configured to provide the higher pressure gas via conduit <NUM> from the gas stream prior to the gas stream flowing to one of the penultimate compressor stage or the final pressure stage.

In some examples, control circuitry <NUM> is configured to adjust the system setpoint based on operating loads such that bleed system <NUM> may extract the higher pressure gas (e.g., via conduit <NUM>) from a compressor stage outside of the last <NUM>% of the compressor stages of turbine engine <NUM>, such as from a seventh or eighth compressor stage, and/or such that bleed system <NUM> may extract the higher pressure gas from a gas stream prior to the prior to the gas stream flowing to a penultimate or final compressor stage. Extracting the higher pressure gas prior to the final compressor stages of turbine engine <NUM> helps avoids an expenditure of compression energy on the higher pressure gas over the final compressor stages of turbine engine <NUM>, potentially increasing a fuel efficiency (e.g., decreasing a thrust-specific fuel consumption (TFSC)) achieved during operation of turbine engine <NUM>.

Bleed system <NUM> can include any suitable jet pump that is configured to be controlled by control circuitry <NUM> to adjust a ratio of a lower pressure gas and a higher pressure gas mixed by the jet pump. The jet pump can include a variable nozzle or other variable geometry the enables variable mixing of bleed air to meet the minimum pressure and flow requirements for gas loads <NUM> served by bleed system <NUM>.

In examples, jet pump <NUM> can be sized and controlled such that jet pump bypass valve <NUM> can be eliminated. Jet pump <NUM> may be configured to position such that the flow restriction and pressure drop of the HP air flow path is reduced adequately such that jet pump bypass valve <NUM> can be eliminated.

<FIG> is a conceptual diagram of an example bleed system <NUM> including an example jet pump <NUM> and control circuitry <NUM>. Portions of jet pump <NUM> are illustrated in cross-section with a cutting plane parallel to the page. A body <NUM> of jet pump <NUM> ("pump body <NUM>") defines a first inlet <NUM> configured to receive a first gas flow (e.g., lower pressure gas via conduit <NUM>) and a second inlet <NUM> configured to receive a second gas flow (e.g., higher pressure gas from conduit <NUM>). Jet pump <NUM> is configured to combine the first gas flow received via first inlet <NUM> and the second gas flow received via second inlet <NUM> to generate a mixed gas in an outlet region <NUM> defined by pump body <NUM>. Jet pump <NUM> is configured to issue a flow of the mixed gas (e.g., to supply conduit <NUM>) via a pump outlet <NUM> defined by pump body <NUM>. In examples, jet pump <NUM> is configured to issue the flow of mixed gas substantially along an axis L defined by jet pump <NUM> and intersecting pump outlet <NUM>. Axis L may be perpendicular to the cutting plane of <FIG>.

In examples, pump body <NUM> defines a diffuser <NUM> configured to allow an expansion of the mixed gas as the mixed gas flows toward pump outlet <NUM>. Jet pump <NUM> may be configured such that the mixed gas expands and cools as the mixed gas flows through diffuser <NUM> toward pump outlet <NUM>. Jet pump <NUM> may be configured to cause the mixed gas to cool (e.g.,to be at a lower temperature than the higher pressure supply <NUM> alone) to reduce a cooling load on, for example, PCL <NUM> or another cooling component. In examples, jet pump <NUM> is configured to receive a higher pressure gas at a first temperature via one of first inlet <NUM> or second inlet <NUM> and a lower pressure gas at a second temperature less than the first temperature via the other of first inlet <NUM> or second inlet <NUM>. Diffuser <NUM> may be configured such that as the mixed gas flows through outlet region <NUM> toward pump outlet <NUM>, the expansion of the mixed gas results in a mixed gas temperature less than at least the first temperature of the higher pressure gas. In examples, the diffuser <NUM> is configured such that the expansion results in a mixed gas temperature less than the second temperature of the lower pressure gas. Diffuser <NUM> may substantially surround outlet region <NUM> and define an increasing flow area (or volume) for the mixed gas as the mixed gas flows within outlet region <NUM> toward pump outlet <NUM>. For example, diffuser <NUM> may be configured such that a cross-sectional dimension R perpendicular to axis L and intersecting diffuser <NUM>, increases as the mixed flow flows within outlet region <NUM> toward pump outlet <NUM>. For example, dimension R may be a radius if pump body <NUM> is circular in cross-section (taken orthogonal to axis L).

Jet pump <NUM> is configured to produce the mixed gas in outlet region <NUM> by at least mixing the first gas flow received via first inlet <NUM> and the second gas flow received via second inlet <NUM> in a mixing ratio. The mixing ratio defines the relative proportion of the second gas flow to the first gas flow combined when jet pump <NUM> produces the mixed gas. In examples, the mixing ratio defines a ratio of a mass of a second gas of the second gas flow to a mass of a first gas of the first gas flow. The mass of the second gas and the mass of the first gas may be defined as mass quantities, mass flow rates, or any other mass-dependent parameters of the second gas flow and the first gas flow. The first gas and the second gas may be gases having the same or a substantially similar compositions. In examples, air comprises the first gas and the second gas.

In examples, the second gas flow has a pressure different from a pressure of the first gas flow. For example, one of the second gas flow or the first gas flow may be higher pressure gas received via conduit <NUM> (<FIG>, <FIG>) and the other of the second gas flow or the first gas flow may be a lower pressure gas received via conduit <NUM>. The mixing ratio may define the relative proportion of the higher pressure gas to the lower pressure gas combined to produce the mixing ratio.

Jet pump <NUM> is configured to alter the mixing ratio in order to establish a steady-state mixing ratio which produces a fluid parameter of the mixed gas satisfying the system setpoint for the fluid parameter sensed by sensor <NUM>, <NUM>, <NUM> (<FIG>, <FIG>). For example, if the fluid parameter sensed by sensor <NUM>, <NUM><NUM> is a pressure and the system setpoint is a pressure setpoint, jet pump <NUM> may be configured to establish a steady-state mixing ratio that causes a certain amount of the second gas (e.g., a higher pressure gas) to mix with a certain amount of the first gas (e.g., the lower pressure gas) such that the mixed gas exiting pump outlet <NUM> generates a pressure at sensor <NUM>, <NUM>, <NUM> satisfying the pressure setpoint. In examples, jet pump <NUM> is configured to establish the steady-state mixing ratio by controlling the mass flow of a higher pressure gas received from turbine engine <NUM> (e.g., via conduit <NUM> (<FIG>,<FIG> )) and/or the lower pressure gas received from turbine engine <NUM> (e.g., from conduit <NUM>). In examples, the system setpoint is defined by a range of values around a central setpoint value, and the fluid parameter of the mixed gas satisfies the system setpoint when the fluid parameter falls within the range. In examples, the system setpoint is defined by a specific setpoint value, and the fluid parameter of the mixed gas satisfies the system setpoint when the fluid parameter is substantially equal to (e.g., within <NUM>%, <NUM>%, <NUM>%, or some other percentage of) the specific setpoint value.

Jet pump <NUM> may be configured to control the mass flows in any manner. In examples, jet pump <NUM> defines a flow area to control the mass flow. For example, jet pump <NUM> may be configured to define a flow area <NUM> configured to enable passage therethrough of the second gas flow received via second inlet <NUM>. In examples, flow area <NUM> is an area defined between an internal body <NUM> and a restriction device <NUM>. Internal body <NUM> may define a perimeter <NUM> defining an opening for the second gas to flow into outlet region <NUM> from second inlet <NUM>, and restriction device <NUM> may be configured to restrict the flow of the second gas through the opening defined by perimeter <NUM>. In some examples, restriction device <NUM> is configured to insert into the opening defined by perimeter <NUM>. Internal body <NUM> may define a chamber <NUM> configured to receive the second gas flow and cause the second gas to flow through the opening defined by perimeter <NUM>. Internal body <NUM> may be, for example, a nozzle body, and restriction device <NUM> may be a needle configured to restrict flow through a nozzle opening defined by the nozzle body. Internal body <NUM> may be mechanically supported by pump body <NUM>.

Jet pump <NUM> may be configured to alter the mixing ratio by altering a dimension of flow area <NUM>. Jet pump <NUM> may be configured such that the dimension of flow area <NUM> controls a mass flow of the second gas flow, such that the dimension of flow area <NUM> controls the mixing ratio defined. In examples, jet pump <NUM> includes a translating member <NUM> configured to translate relative to pump body <NUM> to alter a dimension of flow area <NUM>. Translating member <NUM> may include restrictive device <NUM>. In examples, translating member <NUM> and/or restricting device <NUM> is configured as a jet pump needle. Translating member <NUM> may be configured to cause restrictive device <NUM> to translate relative to perimeter <NUM> when translating member <NUM> translates relative to pump body <NUM>. Restrictive device <NUM> may be configured to alter the dimension of flow area <NUM> when restrictive device <NUM> translates. For example, restrictive device <NUM> may be configured to decrease flow area <NUM> when restrictive device <NUM> translates in a first direction D1 toward perimeter <NUM>. Restrictive device <NUM> may be configured to increase a flow area <NUM> when restrictive device <NUM> translates in a second direction D2 away from perimeter <NUM>. Hence, jet pump <NUM> may be configured to alter the mixing ratio of the second gas flow (e.g., the higher gas flow) to the first gas flow (e.g., the lower gas flow) combined to produce the mixed gas in outlet region <NUM> by causing a translation of translating member <NUM>, e.g., under the control of control circuitry <NUM>.

In examples, bleed system <NUM> includes a device <NUM> configured to exert a mechanical force on jet pump <NUM> to cause jet pump <NUM> to alter the mixing ratio. Control circuitry <NUM> may be configured to cause device <NUM> to exert the mechanical force on jet pump <NUM>. In examples, device <NUM> is configured to cause translating member <NUM> to translate when device <NUM> exerts the mechanical force on jet pump <NUM>. Device <NUM> may be configured to exert the mechanical force on jet pump <NUM> in any suitable manner. In some examples, device <NUM> is configured to provide a pressurized control fluid (e.g., air, fuel, or hydraulic fluid) via a control fluid conduit <NUM> to jet pump <NUM> to exert the mechanical force on jet pump <NUM>. Device <NUM> may include, for example, a torque motor configured to provide the pressurized control fluid. In some examples, the torque motor is configured to receive an inlet flow of gas from bleed system <NUM>, an engine fuel system, or an aircraft hydraulic system and generate the pressurized control fluid using the inlet flow. In some examples, device <NUM> includes an electric motor configured to generate a torque and/or linear force to exert the mechanical force on jet pump <NUM>. For example, device <NUM> may be configured to rotate a nut threadably engaged with jet pump <NUM> to exert the mechanical force on jet pump <NUM>. In some examples, device <NUM> includes a linear motor configured to generate a linear thrust to exert the mechanical force on jet pump <NUM>.

Control circuitry <NUM> may be configured to transmit a control signal to device <NUM> to cause device <NUM> to exert the mechanical force on jet pump <NUM>. In examples, control circuitry <NUM> is configured to transmit the control signal to device <NUM> via communication link <NUM>. Device <NUM> may be configured to exert the mechanical force on jet pump <NUM> in response to the control signal received, such that the control signal from control circuitry <NUM> causes jet pump <NUM> to alter the mixing ratio. Control circuitry <NUM> is configured to transmit the control signal to device <NUM> in response to a signal indicative of a fluid parameter received from sensor <NUM> (<FIG>, <FIG>) via communication link <NUM>. In examples, control circuitry <NUM> is configured to compare the indicative signal to a system setpoint (e.g., a system setpoint received via communication link <NUM>) and transmit the control signal to device <NUM> via communication link <NUM> based on the comparison. In some example, control circuitry <NUM> is configured to establish the system setpoint based on one or more load signals received via communication links <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

For example, control circuitry <NUM> may receive a signal from sensor <NUM>, <NUM> or <NUM> (<FIG>, <FIG>) via communication link <NUM> indicative of a fluid parameter of the mixed gas at a location within bleed system <NUM>, such as supply conduit <NUM>. Control circuitry <NUM> may compare the indicative signal to a system setpoint and, based on the comparison, transmit a control signal via communication link <NUM> causing device <NUM> to exert a mechanical force on jet pump <NUM>. Jet pump <NUM> may alter the mixing ratio of the second gas flow received via second inlet <NUM> (e.g., a higher pressure gas received via conduit <NUM>) to the first gas flow received via first inlet <NUM> (e.g., a lower pressure gas received via conduit <NUM>) in response to the mechanical force. The altered mixing ratio may alter the fluid parameter of the mixed gas within outlet region <NUM> of jet pump <NUM>, causing the fluid parameter of the mixed gas at the location within bleed system <NUM> to alter. Sensor <NUM>, <NUM>, <NUM> may sense the altered fluid parameter within bleed system <NUM> and communicate a signal indicative of the altered fluid parameter to control circuitry <NUM>. When the signal indicative of the altered fluid parameter indicates a fluid parameter satisfying the system setpoint, control circuitry <NUM> may communicate with device <NUM> to cause device <NUM> to cease causing jet pump <NUM> to alter the mixing ratio.

In examples, jet pump <NUM> is configured such that the mechanical force exerted by device <NUM> causes translating member <NUM> to translate to alter the mixing ratio. In examples, translating member <NUM> includes a shaft <NUM> configured to translate relative to pump body <NUM> when the mechanical force is exerted on shaft <NUM>. Shaft <NUM> may be configured to cause restriction device <NUM> to translate when shaft <NUM> translates. In examples, jet pump <NUM> is configured to cause the control fluid received via conduit <NUM> to exert the force on shaft <NUM>. For example, jet pump <NUM> may be configured to cause the control fluid to exert a pressure on a pressure area <NUM> defined by jet pump <NUM> to exert the mechanical force on jet pump <NUM>. Jet pump <NUM> may be configured to cause shaft <NUM> to translate when the control fluid exerts the mechanical force on pressure area <NUM>. In some examples, jet pump <NUM> includes a piston <NUM> defining pressure area <NUM> and configured such that the pressure exerted on pressure area <NUM> causes piston <NUM> to exerts a force on shaft <NUM>, causing shaft <NUM> to translate relative to pump body <NUM>. Translation of shaft <NUM> relative to pump body <NUM> may cause translation of restriction device <NUM> relative to perimeter <NUM>, altering a dimension of flow area <NUM> and altering the mixing ratio of the mixed gas produced by jet pump <NUM>.

In some examples, jet pump <NUM> is configured to produce a resisting force opposing the mechanical force exerted by device <NUM>, such that jet pump <NUM> may be caused to both increase and decrease the mixing ratio by a mechanical force which acts in a single direction. The resisting force produced by jet pump <NUM> may allow device <NUM> to be configured to generate the mechanical force in only a single direction (e.g., the single direction produced when a control fluid acts on pressure area <NUM>), as opposed to requiring a configuration of device <NUM> capable of exerting the mechanical force in multiple directions. In examples, jet pump <NUM> is configured such that the resisting force produced causes translation of translating member <NUM> in a direction (e.g., the direction D1) substantially opposite a translating direction (e.g., the direction D2) of translating member <NUM> caused by the mechanical force exerted by device <NUM>. Jet pump <NUM> may be configured to alter the mixing ratio when the mechanical force on translating member <NUM> provided by device <NUM> is either greater than or less than the resisting force on translating member <NUM> provided by jet pump <NUM>. For example, jet pump <NUM> may be configured such that when the mechanical force exerted on translating member <NUM> is greater than the resisting force exerted on translating member <NUM>, translating member <NUM> translates in the direction D2 to alter the mixing ratio. Jet pump <NUM> may be configured such that when the mechanical force exerted on translating member <NUM> is less than the resisting force exerted on translating member <NUM>, translating member <NUM> translates in the direction D1 to alter the mixing ratio. Hence, jet pump <NUM> may be configured such that variation in a magnitude of the mechanical force exerted by device <NUM> causes jet pump <NUM> to alter the mixing ratio, such that device <NUM> may be configured to exert the mechanical force in only a single direction.

Jet pump <NUM> may be configured to establish a steady-state (e.g., unaltering and/or unvarying) mixing ratio when the mechanical force exerted on translating member <NUM> substantially equals the resisting force exerted on translating member <NUM> by jet pump <NUM>. Jet pump <NUM> may be configured such that when device <NUM> exerts a mechanical force on translating member <NUM> which substantially equals the resisting force exerted on translating member <NUM> by jet pump <NUM>, jet pump <NUM> establishes translating member <NUM> in a substantially stationary position relative to pump body <NUM> to establish a substantially steady-state mixing ratio.

In examples, jet pump <NUM> includes a compressible and/or extendable element <NUM> such as a spring to generate the resisting force. Element <NUM> may be configured such that, when the mechanical force exerted by device <NUM> causes a compression or extension of element <NUM>, element <NUM> generates the resisting force in a direction opposing the mechanical force. In some examples, jet pump <NUM> (e.g., pump body <NUM>) defines a chamber <NUM> configured to hold a compressible gas (e.g., air) which acts against a second pressure area <NUM> to generate the resisting force. Second pressure area <NUM> may be, for example, an area on a side of piston <NUM> opposite the side defining pressure area <NUM>. Chamber <NUM> may be configured such that, when the mechanical force exerted by device <NUM> causes a compression of the gas within chamber <NUM>, the compression of the gas causes chamber <NUM> to the generate the resisting force in a direction opposing the mechanical force. In some examples, chamber <NUM> includes a fluid conduit <NUM> defining a flow path for the compressible gas to enter and/or exit chamber <NUM>. In some examples, fluid conduit <NUM> is fluidly coupled to bleed system <NUM>.

Jet pump <NUM> may be configured to vary a magnitude of the resisting force based on a position of translating member <NUM>, such that the mixing ratio established by jet pump <NUM> is based on a magnitude of the mechanical force exerted by device <NUM>. For example, compressible element <NUM> may be configured such that the resisting force increases as compressible element <NUM> is further compressed and/or extended. Chamber <NUM> may be configured such that the resisting force increases as a gas within chamber <NUM> is further compressed. This may provide a measure of feedback to reduce overshoot, response time, settling time, and/or other control characteristics when control circuitry <NUM> causes jet pump <NUM> to alter the mixing ratio in response to a signal from sensor <NUM>. For example, when device <NUM> is configured to provide a control fluid via control fluid conduit <NUM> to exert the mechanical force by acting on pressure area <NUM>, control circuitry <NUM> may cause the indicative signal to smoothly approach a system setpoint by directing device <NUM> to increase or decrease the pressure of the control fluid as the system setpoint is approached. This may increase the responsiveness of bleed system <NUM> when control circuitry <NUM> changes a system setpoint for the fluid parameter based on a setpoint signal received via communication link <NUM> and/or one or more loads signals received via communication links <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

In examples, bleed system <NUM> is configured to provide a pneumatic feedback to jet pump <NUM> to cause jet pump <NUM> to alter the mixing ratio. Bleed system <NUM> may be configured to substantially sense a parameter of the mixed gas at a location in bleed system <NUM> using feedback line <NUM> and provide the sensed parameter to jet pump <NUM>, device <NUM>, and/or another component of bleed system <NUM> to cause jet pump <NUM> to alter the mixing ratio. In examples, the sensed parameter is a pressure and feedback line <NUM> is a pneumatic feedback line configured to substantially port a portion of the mixed gas to jet pump <NUM>, device <NUM>, and/or another component of bleed system <NUM> from the sensed location. Feedback line <NUM> may sense the mixed gas at any location within bleed system <NUM>. In examples, feedback line <NUM> is configured to sense the fluid parameter <NUM> at a location substantially defined by diffuser <NUM>. In some examples, feedback line <NUM> is configured to port some portion of the mixed gas from diffuser section <NUM> to device <NUM> to cause jet pump <NUM> to alter the mixing ratio.

Device <NUM> may be configured to vary the magnitude of the mechanical force exerted on jet pump <NUM> to cause jet pump <NUM> to alter the mixing ratio. Device <NUM> may be configured to vary the magnitude of the mechanical force to, for example, cause the mechanical force to exceed the resistance force or cause the resistance force to exceed the mechanical force in order to alter the mixing ratio. For example, device <NUM> may be configured to increase or decrease a pressure of the control fluid received by jet pump <NUM> via control fluid conduit <NUM> to vary the magnitude of the mechanical force exerted. Device <NUM> may be configured to vary a rotary torque or linear force exerted on jet pump <NUM> to vary the magnitude of the mechanical force exerted. In examples, device <NUM> is configured to vary the magnitude of the force exerted based on the control signal received from control circuitry <NUM> via communication link <NUM>. In examples, device <NUM> is configured to vary the magnitude based on a signal characteristic (e.g., a frequency and/or amplitude) of the signal received from control circuitry <NUM>.

In examples, jet pump <NUM> is configured to utilize air as control fluid. Device <NUM> may be configured to pressurize the air and provide the pressurized air as the control fluid via control fluid conduit <NUM>. The use of air as a control fluid may improve a responsiveness and/or reliability of jet pump <NUM> in higher temperature environments, such as environments in close proximity to an operating engine such as turbine engine <NUM>. In examples, jet pump <NUM> is configured to operate within an environment having a temperature greater than about <NUM> degrees Celsius (<NUM> degrees Fahrenheit), greater than about <NUM> degrees Celsius (<NUM> degrees Fahrenheit), and/or <NUM> degrees Celsius (<NUM> degrees Fahrenheit). In other examples, jet pump <NUM> and device <NUM> may be configured to use a different fluid as the control fluid, such as water, oil, or another hydraulic fluid.

<FIG> illustrates a flow diagram of an example technique for controlling a mixed gas within a bleed system. Although the technique is described with reference to jet pump <NUM> (<FIG>), in other examples, the technique may be used with device. In addition, control circuitry <NUM> alone or in combination with controllers of other devices can perform any part of the technique shown in <FIG>.

Control circuitry <NUM> receives a signal indicative of a fluid parameter of a mixed gas (<NUM>). The signal may indicate the fluid parameter of the mixed gas in a bleed system <NUM> configured to provide the mixed gas to one or more gas loads <NUM>, such as ECS <NUM>, fuel tank system <NUM>, ADU <NUM>, and/or anti-icing system <NUM>. The one or more gas loads may be configured to operate as transient loads within bleed system <NUM>, such that the overall demands of gas loads <NUM> may vary during operation of bleed system <NUM>. In examples, control circuitry <NUM> receives the indicative signal from sensor <NUM>, <NUM>, <NUM> configured to sense the fluid parameter of the mixed gas within bleed system <NUM>. The fluid parameter may be, for example, a pressure, a temperature, a flow rate, or some other fluid parameter of the mixed gas within bleed system <NUM>.

Control circuitry <NUM> causes jet pump <NUM> to alter the mixing ratio based on the signal indicative of the fluid parameter received (<NUM>). In examples, control circuitry <NUM> compares the indicative signal to a system setpoint and causes jet pump <NUM> to alter the mixing ratio based on the comparison. Control circuitry <NUM> may be configured to receive the system setpoint via communication link <NUM> or establish the system setpoint, e.g., as described below. Control circuitry <NUM> is configured to cause jet pump <NUM> to respond to varying setpoints. For example, control circuitry <NUM> may receive a first setpoint and cause jet pump <NUM> to alter the mixing ratio such that the fluid parameter sensed by sensor <NUM> substantially matches and/or satisfies the system setpoint. Control circuitry <NUM> may subsequently receive a second setpoint different from the first setpoint and cause jet pump <NUM> to alter the mixing ratio such that the fluid parameter sensed by sensor <NUM>, <NUM>,<NUM> substantially matches and/or satisfies the second setpoint.

In some examples, control circuitry <NUM> is configured to establish the system setpoint. In examples, control circuitry receives one or more load signals from gas loads <NUM> via communication links <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and establishes the system setpoint based on the one or more load signals.

Control circuitry <NUM> may be configured to cause jet pump <NUM> alter the mixing ratio by at least altering a mass flow of the higher pressure gas and/or the lower pressure gas received from turbine engine <NUM> as jet pump <NUM> produces the mixed gas. For example, if jet pump <NUM> defines flow area <NUM> to control the mass flow, then control circuitry <NUM> may cause jet pump <NUM> to alter a dimension of flow area <NUM> to alter the mixing ratio, such as by causing jet pump <NUM> to translate restriction device <NUM> to alter the dimension of flow area <NUM>.

In examples, control circuitry <NUM> is configured to cause device <NUM> to exert a mechanical force on jet pump <NUM> to cause jet pump <NUM> to alter the mixing ratio. Device <NUM> may be configured to cause translating member <NUM> to translate when control circuitry causes device <NUM> to exert the mechanical force. In examples, device <NUM> is configured to provide a pressurized control fluid (e.g., air) via a control fluid conduit <NUM> to jet pump <NUM> to exert the mechanical force by acting on pressure area <NUM>. In some examples, device <NUM> includes an electric motor configured to generate a torque and/or linear force to exert the mechanical force on jet pump <NUM>.

Device <NUM> may exert the mechanical force in a single direction on jet pump <NUM> to cause jet pump <NUM> to alter the mixing ratio (e.g., to increase or decrease the mixing ratio). Jet pump <NUM> may produce a resisting force opposing the mechanical force exerted by device <NUM>. Jet pump <NUM> may alter the mixing ratio when the mechanical force on translating member <NUM> provided by device <NUM> is either greater than or less than the resisting force on translating member <NUM> provided by jet pump <NUM>. In examples, jet pump <NUM> generates the resisting force using compressible and/or extendable element <NUM> and/or chamber <NUM>. Jet pump <NUM> may vary a magnitude of the resisting force based on a position of translating member <NUM>, such that the mixing ratio established by jet pump <NUM> is based on a magnitude of the mechanical force exerted by device <NUM>.

In examples, control circuitry <NUM> causes device <NUM> to vary the magnitude of the mechanical force exerted on jet pump <NUM> to cause jet pump <NUM> to alter the mixing ratio. Control circuitry may cause device <NUM> to vary the magnitude of the mechanical force by transmitting a control signal to device <NUM> via communication link <NUM>. Control circuitry <NUM> may cause device <NUM> to vary the magnitude of the mechanical force to cause the mechanical force to exceed the resistance force or cause the resistance force to exceed the mechanical force. In examples, control circuitry <NUM> causes device <NUM> to increase or decrease a pressure of the control fluid received by jet pump <NUM> via control fluid conduit <NUM> to vary the magnitude of the mechanical force. In examples, control circuitry <NUM> causes device <NUM> to vary a rotary torque or linear force exerted on jet pump <NUM> to vary the magnitude of the mechanical force.

Control circuitry <NUM> may include any suitable arrangement of hardware, software, firmware, or any combination thereof, to perform the techniques attributed to control circuitry <NUM> herein. Examples of control circuitry <NUM> include any one or more microprocessors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components. When control circuitry <NUM> includes software or firmware, control circuitry <NUM> further includes any necessary hardware for storing and executing the software or firmware, such as one or more processors or processing units. In general, a processing unit may include one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components.

A system setpoint for bleed system <NUM> may be stored in a memory of control circuitry <NUM> or in another device communicatively coupled to control circuitry <NUM>. The memory may include any volatile or non-volatile media, such as a random access memory (RAM), read only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, and the like. In addition, in some examples, the memory or another memory may also store executable instructions for causing control circuitry <NUM> described herein to perform the actions attributed to it.

Communication links <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be hard-line and/or wireless communications links. Communication links <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may comprise some portion of control circuitry <NUM>, sensor <NUM>, and/or one or more of gas loads <NUM>. Communication links <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may comprise a wireless Internet connection, a direct wireless connection such as wireless LAN, Bluetooth™, Wi-Fi™, and/or an infrared connection. Communication links <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may utilize any wireless or remote communication protocol.

Sensor <NUM>, bleed temperature sensor <NUM>, manifold temperature sensor <NUM>, first manifold pressure sensor <NUM>, and/or second manifold pressure sensor <NUM> (collectively "bleed system sensors") may be configured to generate a signal indicative of a fluid parameter at any location within bleed system <NUM>. One or more of the bleed system sensors may be configured to generate the signal as a result of an interaction with the mixed gas within bleed system <NUM>. One or more of the bleed system sensors may include a transducer configured to transduce the interaction into the signal indicative of the fluid parameter. The indicative signal may be an analog electrical signal or a digital signal. In some examples, one or more of the bleed system sensors may include processing circuitry configured to interpret a response of the transducer and generate the indicative signal, and/or control circuitry <NUM> may include processing circuitry configured to interpret a response of the transducer and generate the indicative signal. One or more of the bleed system sensors may be configured to communicate the indicative signal indicative to other devices in data communication the one or more of the bleed system sensors.

Intermediate pressure check valve <NUM>, high pressure valve <NUM>, jet pump bypass valve <NUM>, mid-pressure valve <NUM>, over pressure shut off valve <NUM>, fan air valve <NUM>, flow control valve <NUM>, valve <NUM>, valve <NUM>, and/or valve <NUM> (collectively "bleed system valves") may be configured to operate in any manner and with any type of valve operation system. One or more of the bleed system valves may be a pneumatically operated valve, a hydraulically operated valve, a manually operated valve, a motor-driven valve, or a valve configured to operate in another manner. One or more of the bleed system valves may be configured to operate based on a communication from control circuitry <NUM> or other control circuitry. Control circuitry <NUM> or the other control circuitry may be configured to cause operation of one or more of the bleed system valves based on the fluid parameter of the mixed gas within bleed system <NUM>, other parameters within bleed system <NUM>, other operations conducted by aircraft <NUM>, and/or other reasons.

The techniques described in this disclosure, including those attributed to control circuitry <NUM> and other control circuitry, processing circuitry, sensors, or various constituent components, may be implemented, at least in part, in hardware, software, firmware or any combination thereof. For example, various aspects of the techniques may be implemented within one or more processors, including one or more microprocessors, DSPs, ASICs, FPGAs, or any other equivalent integrated or discrete logic circuitry, as well as any combinations of such components, embodied in any suitable device. Processing circuitry, control circuitry, and sensing circuitry, as well as other processors, controllers, and sensors described herein, may be implemented at least in part as, or include, one or more executable applications, application modules, libraries, classes, methods, objects, routines, subroutines, firmware, and/or embedded code, for example. In addition, analog circuits, components, and circuit elements may be employed to construct one, some or all of the control circuitry and sensors, instead of or in addition to the partially or wholly digital hardware and/or software described herein. Accordingly, analog or digital hardware may be employed, or a combination of the two.

In one or more examples, the functions described in this disclosure may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on, as one or more instructions or code, a computer-readable medium and executed by a hardware-based processing unit. The computer-readable medium may be an article of manufacture including a non-transitory computer-readable storage medium encoded with instructions. Instructions embedded or encoded in an article of manufacture including a non-transitory computer-readable storage medium encoded, may cause one or more programmable processors, or other processors, to implement one or more of the techniques described herein, such as when instructions included or encoded in the non-transitory computer-readable storage medium are executed by the one or more processors. Example non-transitory computer-readable storage media may include RAM, ROM, programmable ROM (PROM), erasable programmable ROM (EPROM), electronically erasable programmable ROM (EEPROM), flash memory, a hard disk, a compact disc ROM (CD-ROM), a floppy disk, a cassette, magnetic media, optical media, or any other computer readable storage devices or tangible computer readable media.

In some examples, a computer-readable storage medium comprises non-transitory medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. In certain examples, a non-transitory storage medium may store data that can, over time, change (e.g., in RAM or cache).

The functionality described herein may be provided within dedicated hardware and/or software modules.

Claim 1:
A system comprising:
a jet pump (<NUM>) configured to receive a lower pressure gas from a lower pressure stage of a turbine engine (<NUM>) and receive a higher pressure gas from a higher pressure stage of the turbine engine (<NUM>),
wherein the jet pump (<NUM>) is configured to combine the lower pressure gas and the higher pressure gas to produce a mixed gas, and
wherein the jet pump (<NUM>) is configured to alter a mixing ratio of the higher pressure gas to the lower pressure gas combined when the jet pump (<NUM>) produces the mixed gas; and
control circuitry (<NUM>) configured to receive a signal indicative of a fluid parameter of the mixed gas, wherein the control circuitry (<NUM>) is configured to cause the jet pump (<NUM>) to alter the mixing ratio based on the signal,
wherein the control circuitry (<NUM>) is configured to determine a setpoint for the fluid parameter, and wherein the control circuitry (<NUM>) is configured to compare the fluid parameter indicated by the signal with the setpoint and control the jet pump (<NUM>) to alter the mixing ratio based on the comparison, and
wherein the control circuitry (<NUM>) is configured to receive a load signal from a load configured to receive the mixed gas, wherein the control circuitry (<NUM>) is configured to determine the setpoint based on the load signal.