Abstract:
A method and system for an air management system (AMS) is provided. The AMS includes a jet pump assembly including a motive air inlet, a plurality of suction inlets, and a single outlet. The AMS also includes a supply piping arrangement including a conduit configured to channel relatively higher pressure air from a compressor to the motive air inlet, a conduit configured to channel relatively higher pressure air from the compressor to at least one of the plurality of suction inlets through a shutoff valve, and a conduit configured to channel relatively lower pressure air from the compressor to at least one of the plurality of suction inlets. The AMS further includes an outlet piping arrangement configured to channel outlet air from said jet pump assembly to a distribution system. A pressure regulation strategy of the motive jet pump flow allows optimization of engine fuel burn and/or thrust, depending on which is most important to the aircraft during any flight phase.

Description:
BACKGROUND 
       [0001]    The field of the disclosure relates generally to air management systems and, more particularly, to an integrated air management system having reduced weight and optimized performance. 
         [0002]    At least some known aircraft air management systems (AMS) include supply sources for high-pressure (HP), low-pressure (LP). Typically, the HP and LP flows are supplied directly from a respective bleed port on an engine on the aircraft. Various pressure and flow requirements may not be met on some engines for all ranges of operation of the aircraft. For these cases, a mixed mode bleed may be supplied through a jet pump. The jet pump receives both HP and LP air flow, mixes the flows in selectable proportions and delivers the mixed mode bleed air to the AMS. Various pressure and flow requirements may not be met on some engines for all ranges of operation of the aircraft. Moreover, newer engines tend to have constrained space requirements that do not permit the use of standard architecture jet pump components and simply scaling the standard architecture jet pumps will not be able to mix the HP and LP flows adequately. Moreover, bleeding large quantities of highly compressed air from an engine compressor tends to reduce the efficiency and/or increase the specific fuel consumption of the engine. Such a tendency can affect the overall performance of the gas turbine engine associated with the compressor and/or the entire aircraft. In addition, the use of mixed mode jet pump operation provides air at temperatures/pressure closer to the aircraft needs, allowing for a smaller pre-cooler (heat exchanger), providing an additional weight savings for the aircraft. 
       BRIEF DESCRIPTION 
       [0003]    In one embodiment, an AMS includes a jet pump assembly including a motive air inlet, a plurality of suction inlets, and a single outlet. The AMS also includes a supply piping arrangement including a conduit configured to channel relatively higher pressure air from a compressor to the motive air inlet, a conduit configured to channel relatively higher pressure air from the compressor to at least one of the plurality of suction inlets through a shutoff valve, and a conduit configured to channel relatively lower pressure air from the compressor to at least one of the plurality of suction inlets. The AMS further includes an outlet piping arrangement configured to channel outlet air from the jet pump assembly to a distribution system. 
         [0004]    In another embodiment, a method of operating an integrated air management system (AMS) is provided. The AMS includes a supply system coupled to a compressor of a gas turbine engine and an air distribution system. The method includes generating a flow of distribution air using at least one of a flow of relatively higher pressure air and a flow of relatively lower pressure air in a jet pump assembly, channeling the flow of distribution air to the air distribution system, and controlling a relative flow of the relatively higher pressure air with respect to the flow of relatively lower pressure air to maintain an efficiency of the integrated AMS at a first efficiency level. The method further includes receiving a demand signal and controlling the relative flow of the relatively higher pressure air flow with respect to the flow of relatively lower pressure air to maintain an efficiency of the integrated AMS at a second efficiency level based on the received demand signal. 
         [0005]    In yet another embodiment, an aircraft includes an air management system (AMS) that includes a jet pump assembly configured to operate in a plurality of selectable modes, each of the selectable modes selected using a demand signal from an engine, each of the plurality of selectable modes associated with an efficiency of operation of the AMS. The AMS also includes a an outlet piping arrangement coupled to an outlet of the jet pump assembly and an inlet piping arrangement configured to couple the jet pump assembly to a relatively higher pressure source of air and a relatively lower pressure source of air, the inlet piping arrangement including a plurality of controlled operation valves and configured to receive automatic command signals that command the operation of the plurality of controlled operation valves to align the inlet piping arrangement into the selectable modes. 
     
    
     
       DRAWINGS 
         [0006]    These and other features, aspects, and advantages of the present disclosure will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
           [0007]      FIG. 1  is a schematic illustration of an exemplary gas turbine engine in accordance with an example embodiment of the present disclosure. 
           [0008]      FIG. 2  is a perspective view of an aircraft including a fuselage and a wing. 
           [0009]      FIG. 3  is a three dimensional (3D) isometric piping view of an aircraft air management system (AMS) supply source. 
           [0010]      FIG. 4  is a graph of engine bleed pressure at various engine power settings. 
           [0011]      FIG. 5  is a graph of engine bleed temperature at various engine power settings. 
           [0012]      FIG. 6  is a graph of engine specific fuel consumption (SFC) at various engine power settings. 
           [0013]      FIG. 7  is a flow chart of a method of operating an integrated air management system (AMS) that includes a supply system coupled to a compressor of a gas turbine engine and an air distribution system. 
       
    
    
       [0014]    Unless otherwise indicated, the drawings provided herein are meant to illustrate features of embodiments of this disclosure. These features are believed to be applicable in a wide variety of systems including one or more embodiments of this disclosure. As such, the drawings are not meant to include all conventional features known by those of ordinary skill in the art to be required for the practice of the embodiments disclosed herein. 
       DETAILED DESCRIPTION 
       [0015]    In the following specification and the claims, reference will be made to a number of terms, which shall be defined to have the following meanings. 
         [0016]    The singular forms “a”, “an”, and “the” include plural references unless the context clearly dictates otherwise. 
         [0017]    “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not. 
         [0018]    Approximating language, as used herein throughout the specification and claims, may be applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is related. Accordingly, a value modified by a term or terms, such as “about”, “approximately”, and “substantially”, are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value. Here and throughout the specification and claims, range limitations may be combined and/or interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. 
         [0019]    Embodiments of an Air Management System (AMS) as described herein provide air to aircraft system at various flow rates and pressures to fulfill the operational and environmental requirements of the aircraft. Such requirements define considerations of piping optimization for using a light weight and compact integrated AMS. In the example embodiment, one pump body and associated valves permits three operating modes: a) bleed air extraction from low-pressure (LP) port of a compressor only, b) bleed air extraction from a high-pressure (HP) port of the compressor only, and mixed bleed air extraction from the HP and LP ports. One set of downstream piping serves all three operating modes. The example embodiment include packaging benefits, such as, but, not limited to reduced weight, smaller bi-fi, and fuel-driven valves confined to the core fire-zone. The selected compressor bleed ports are also able to be optimized for an engine efficiency improvement. The cycle efficiency penalty for aircraft bleed is minimized by designing ports on the lowest compressor stage that meets aircraft bleed requirements. Typically, the set low port is based on pressure available to the turbine at an end-of-cruise (non-icing operation). The energy requirements for icing tend to drive LP ports into higher stages of the compressor. However, mixing the HP and LP flows simulates a variable intermediate stage port, allowing a lower port to be selected for efficiency while still providing capability in icing and increasing efficiency. The example embodiment facilitates covering gaps in the temperature/pressure profile where HP air is too hot and LP pressure is too low. The example embodiment provides for power management optimization based on a component and engine efficiency improvement. The HP pressure is regulated and is variable using a Jet Pump Shut Off Valve (JPSOV) and a downstream pressure sensor feedback to provide feedback for improved jet pump efficiency at each operational point. The JPSOV regulation strategy of constant pressure output reduces the contribution of HP flow at high power. Embodiments of the present disclosure also permit higher rated thrust at the same engine turbine temperatures as traditional designs. At low power, the regulated HP/LP pressure ratio increases, which results in greater HP flow contribution. In addition, the use of mixed mode jet pump operation provides air at temperatures/pressure closer to the aircraft demand, allowing for a smaller pre-cooler (heat exchanger), providing an additional weight savings for the aircraft. 
         [0020]      FIG. 1  is a schematic illustration of an exemplary gas turbine engine  10 . Engine  10  includes a low pressure compressor  12 , a high pressure compressor  14 , and a combustor assembly  16 . Engine  10  also includes a high pressure turbine  18 , and a low pressure turbine  20  arranged in a serial, axial flow relationship. Compressor  12  and turbine  20  are coupled by a first shaft  21 , and compressor  14  and turbine  18  are coupled by a second shaft  22 . 
         [0021]    During operation, air flows along a central axis  15 , and compressed air is supplied to high pressure compressor  14 . The highly compressed air is delivered to combustor  16 . Airflow (not shown in  FIG. 1 ) from combustor  16  drives turbines  18  and  20 , and turbine  20  drives low pressure compressor  12  by way of shaft  21 . Gas turbine engine  10  also includes a fan containment case  40 . 
         [0022]      FIG. 2  is a perspective view of an aircraft  100  including a fuselage  102  and a wing  104 . A gas turbine engine  106  is coupled to wing  104  and is configured to supply propulsive power to aircraft  100  and may be a source of auxiliary power to various systems of aircraft  100 . For example, gas turbine engine  106  may supply electrical power and pressurized air to the various systems. In one example, gas turbine engine  106  supplies pressurized air to an aircraft air management system (AMS)  108 . In various embodiments, gas turbine engine  106  supplies a relatively higher pressure air through a first high-pressure conduit  110  and relatively lower pressure air through a second low-pressure conduit  112 . In other embodiments, the relatively higher pressure air, the relatively lower pressure air, and a combination of the relatively higher pressure air and the relatively lower pressure air is generated proximate gas turbine engine  106  and channeled to AMS  108  through a single conduit, for example, first high-pressure conduit  110  or second low-pressure conduit  112 . 
         [0023]      FIG. 3  is a three dimensional (3D) isometric piping view of an aircraft air management system (AMS) supply source  200 . AMS supply source  200  includes a high-pressure (HP) source, such as, but not limited to one or more compressor 10 th  stage bleed ports  202 , low-pressure (LP) source, such as, but not limited to one or more compressor 4 th  stage bleed ports  204 . Air from various combinations of ports  202  and  204  provide high-pressure, low-pressure, and mixed mode flows to a jet pump  205 , which is supplied through a jet pump outlet  207  to a downstream AMS. Typically, the HP and LP flows are supplied directly from bleed ports  202  and  204  from a respective engine. A mixed mode bleed is supplied through a jet pump  205 . Jet pump  205  receives both HP and LP air flow, mixes the flows in selectable proportions in a pre-mixing bowl  206  and delivers the mixed mode bleed air to the AMS through a mixing tube  209 . Upstream duct bends  211  promote a non-uniform flow field between the multiple inlets, promoting swirl in the low-pressure flows without the use of swirl vanes. 
         [0024]    A jet pump shutoff valve (JPSOV)  208  modulates to supply high-pressure air to a throat  210  of jet pump  205 . A pressure sensor  213  between JPSOV  208  and throat  210  provides pressure feedback to control a position of JPSOV  208  to provide substantially constant selected pressure to throat. A controller  215  may be communicatively coupled to JPSOV  208  and pressure sensor  213 . Controller  215  may include a memory and a processor in communication so that instructions programmed in the memory control the processor to receive a pressure signal from pressure sensor  213  and a threshold value to generate a position command, which is transmitted to JPSOV  208 . A high-pressure shutoff valve (HPSOV)  212  opens and closes to supply high-pressure air from 10 th  stage ports  202  to a first inlet  214 . Check valves  216  and  218  prevent back flow from 10 th  stage ports  202  to 4 th  stage bleed ports  204 . 
         [0025]    AMS supply source  200  operates in three modes where outlet  207  is supplied from low-pressure 4 th  stage bleed ports  204 , from high-pressure bleed ports  202 , and a mixed supply from both low-pressure 4 th  stage bleed ports  204  and high-pressure bleed ports  202 . In a first mode, outlet  207  is supplied from low-pressure 4 th  stage bleed ports  204  with both JPSOV  208  and HPSOV  212  in a closed position. In a second mode, outlet  207  is supplied from high-pressure bleed ports  202  with JPSOV  208  in a closed position and HPSOV  212  in an open position. A third mode is a jet pump mode where HPSOV  212  is in a closed position and JPSOV  208  is in an open position. When in the open position, JPSOV  208  modulates to adjust flow from a single leg of the high-pressure supply portion  220  of AMS supply source  200 . 
         [0026]    A flow sensor  222  is configured to measure an amount of the extracted flow from the 10 th  stage that is directed to AMS supply source  200 . The 10 th  stage bleed measurement is used to maintain the engine operation according to a predetermined air management schedule. Bleeding air from the 10 th  stage may affect other stages of the engine. A map of a range of 10 th  stage flow rates is used to determine an impact for the various flow rates on the engine. The 10 th  stage bleed flow rate is accounted for in thrust schemes and fielding schemes that affect the engine performance. 
         [0027]      FIG. 4  is a graph  300  of engine bleed pressure at various engine power settings. Graph  300  includes an x-axis  302  graduated in units of net thrust of engine (lbf)  106  and a y-axis  304  graduated in units of bleed total pressure (psig). A trace  306  illustrates a lower stage pressure, such as a fourth stage pressure of engine  106 . A trace  308  illustrates an upper stage pressure, such as a tenth stage pressure of engine  106 . Traces  306  and  308  represent the bounds of supply pressure to jet pump  205 . A trace  310  illustrates a thrust versus bleed pressure curve for jet pump operation regulated to maintain approximately 225 psig pressure at throat  210  of jet pump  205 . A trace  312  illustrates a thrust versus bleed pressure curve for jet pump operation regulated to maintain approximately 200 psig pressure at throat  210 . A trace  314  illustrates a thrust versus bleed pressure curve for jet pump operation regulated to maintain approximately 175 psig pressure at throat  210 . A trace  316  illustrates a thrust versus bleed pressure curve for jet pump operation regulated to maintain approximately 150 psig pressure at throat  210 . A trace  318  illustrates a thrust versus bleed pressure curve for jet pump operation regulated to maintain approximately 125 psig pressure at throat  210 . A trace  320  illustrates a thrust versus bleed pressure curve for jet pump operation regulated to maintain approximately 100 psig pressure at throat  210 . A trace  322  illustrates a thrust versus bleed pressure curve for jet pump operation regulated to maintain approximately 75 psig pressure at throat  210 . 
         [0028]      FIG. 5  is a graph  400  of engine bleed temperature at various engine power settings. Graph  400  includes an x-axis  402  graduated in units of net thrust of engine (lbf)  106  and a y-axis  404  graduated in units of bleed total temperature (° C.). A trace  406  illustrates a lower stage temperature, such as a fourth stage temperature of engine  106 . A trace  408  illustrates an upper stage temperature, such as a tenth stage temperature of engine  106 . Traces  406  and  408  represent the bounds of supply temperature to jet pump  205 . A trace  410  illustrates a thrust versus bleed temperature curve for jet pump operation regulated to maintain approximately 225 psig pressure at throat  210  of jet pump  205 . A trace  412  illustrates a thrust versus bleed temperature curve for jet pump operation regulated to maintain approximately 200 psig pressure at throat  210 . A trace  414  illustrates a thrust versus bleed temperature curve for jet pump operation regulated to maintain approximately 175 psig pressure at throat  210 . A trace  416  illustrates a thrust versus bleed temperature curve for jet pump operation regulated to maintain approximately 150 psig pressure at throat  210 . A trace  418  illustrates a thrust versus bleed temperature curve for jet pump operation regulated to maintain approximately 125 psig pressure at throat  210 . A trace  420  illustrates a thrust versus bleed temperature curve for jet pump operation regulated to maintain approximately 100 psig pressure at throat  210 . A trace  422  illustrates a thrust versus bleed temperature curve for jet pump operation regulated to maintain approximately 75 psig pressure at throat  210 . 
         [0029]      FIG. 6  is a graph  500  of engine specific fuel consumption (SFC) at various engine power settings. Graph  500  includes an x-axis  502  graduated in units of net thrust of engine (lbf)  106  and a y-axis  504  graduated in units of specific fuel consumption (SFC) (lbm/hr/lbf). A trace  506  illustrates an engine SFC curve versus engine net thrust when using only a lower compressor stage air for AMS  108 , such as a fourth stage of compressor  12  of engine  106 . A trace  508  illustrates an engine SFC curve versus engine net thrust when using only an upper compressor stage air for AMS  108 , such as a tenth stage of compressor  12 . Traces  506  and  508  represent the bounds of SFC of engine  106  based on AMS demand. A trace  510  illustrates a thrust versus SFC curve for jet pump operation regulated to maintain approximately 225 psig pressure at throat  210  of jet pump  205 . A trace  512  illustrates a thrust versus SFC curve for jet pump operation regulated to maintain approximately 200 psig pressure at throat  210 . A trace  514  illustrates a thrust versus SFC curve for jet pump operation regulated to maintain approximately 175 psig pressure at throat  210 . A trace  516  illustrates a thrust versus SFC curve for jet pump operation regulated to maintain approximately 150 psig pressure at throat  210 . A trace  518  illustrates a thrust versus SFC curve for jet pump operation regulated to maintain approximately 125 psig pressure at throat  210 . A trace  520  illustrates a thrust versus SFC curve for jet pump operation regulated to maintain approximately 100 psig pressure at throat  210 . A trace  522  illustrates a thrust versus SFC curve for jet pump operation regulated to maintain approximately 75 psig pressure at throat  210 . 
         [0030]    Traces  506 - 522  illustrate the benefit of jet pump  205  for improving SFC during operations that demand an output greater than that which only the fourth stage can provide but, that does not demand as much AMS output as the tenth stage can provide. These intermediate ranges are supplied by using tenth stage air to provide motive air to jet pump  205  while the fourth stage supplies air to the suction of jet pump  205 . 
         [0031]    It can be seen that using different levels of intermediate air pressures from jet pump  205 , a SFC can be selected, which can aid engine  106  overall performance or performance during particular maneuvers. 
         [0032]      FIG. 7  is a flow chart of a method  700  of operating an integrated air management system (AMS) that includes a supply system coupled to a compressor of a gas turbine engine and an air distribution system. In the example embodiment, method  700  includes generating  702  a flow of distribution air using at least one of a flow of relatively higher pressure air and a flow of relatively lower pressure air in a jet pump assembly, channeling  704  the flow of distribution air to the air distribution system, and controlling  706  a relative flow of the relatively higher pressure air with respect to the flow of relatively lower pressure air to maintain an efficiency of the integrated AMS at a first efficiency level. Method  700  also includes receiving  708  a demand signal and controlling  710  the relative flow of the relatively higher pressure air flow with respect to the flow of relatively lower pressure air to maintain an efficiency of the integrated AMS at a second efficiency level based on the received demand signal. 
         [0033]    Method  700  optionally includes controlling the relative flow of the relatively higher pressure air flow with respect to the flow of relatively lower pressure air to maintain a predetermined temperature of the distribution air. Method  700  may also include generating a flow of distribution air using one of a first operating mode, a second operating mode, and a third operating mode, the first operating mode generates the flow of distribution air using the flow of relatively lower pressure air in the jet pump assembly, the second operating mode generates the flow of distribution air using the flow of relatively higher pressure air in the jet pump assembly, and the third operating mode generates the flow of distribution air using a mixed flow of relatively lower pressure air and of relatively higher pressure air. Additionally, method  700  may further include channeling the flow of relatively higher pressure air from a high pressure bleed port of the compressor to a suction inlet of the jet pump assembly. Optionally, method  700  may include modulating the flow of relatively higher pressure air using a modulating valve coupled between the high pressure bleed port of the compressor and a supply inlet of the jet pump assembly. Further, method  700  may include modulating the flow of relatively higher pressure air based on a pressure feedback from a pressure sensor positioned between the modulating valve and the supply inlet of the jet pump assembly. Method  700  may also include channeling the flow of relatively higher pressure air from at least one high pressure bleed port of the compressor to a supply inlet of the jet pump assembly and channeling the flow of relatively lower pressure air from at least one low pressure bleed port of the compressor to at least one suction inlet of the jet pump assembly. Optionally, method  700  may also include channeling the flow of relatively lower pressure air to a first suction inlet of the jet pump assembly and to a second suction inlet of the jet pump assembly, an opening of the first suction inlet of the jet pump assembly including a first area, an opening of the second suction inlet of the jet pump assembly including a second area, the first area being larger than the second area. Method  700  may also include channeling the flow of relatively lower pressure air to a first suction inlet of the jet pump assembly and to a second suction inlet of the jet pump assembly, the flow of relatively lower pressure air to first suction inlet of the jet pump assembly including a first velocity, the flow of relatively lower pressure air to the second suction inlet of the jet pump assembly including a second velocity, the first velocity being less than the second velocity. 
         [0034]    Although specific features of various embodiments of the disclosure may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the disclosure, any feature of a drawing may be referenced and/or claimed in combination with any feature of any other drawing. 
         [0035]    This written description uses examples to disclose the embodiments, including the best mode, and also to enable any person skilled in the art to practice the embodiments, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.