The present disclosure generally relates to high speed flight vehicles and, more specifically, to systems and methods for expanding operating ranges of high speed flight vehicles.
Operating conditions at high flight speeds present various challenges to flight vehicle design. For example, a gas turbine engine of a flight vehicle traveling through atmosphere at speeds greater than Mach 3, and more particularly at hypersonic speeds greater than Mach 5, may experience localized temperatures that reach or exceed a material temperature limit. In conventional flight vehicle design, the engine is throttled back as the temperature nears the material temperature limit, thereby to avoid exceeding the material temperature limit. When excessive throttling back is needed due to high temperatures, the engine no longer accelerates the flight vehicle, thereby limiting a top operating speed of the flight vehicle. Additionally, nozzle design may impose limits on the operating range of the flight vehicle. For example, a nozzle configured for speeds greater than Mach 3 may induce over-expansion drag at lower speeds, or may otherwise fail to provide propulsive efficiency across a range of operating speeds of the flight vehicle.
In accordance with one aspect of the present disclosure, a turbine engine for a high speed flight vehicle comprises an inlet air duct having an upstream end for receiving ambient air and a downstream end, the inlet air duct directing a duct air flow from the upstream end to the downstream end, and a fan disposed in the inlet air duct. An engine core is disposed in the inlet air duct and operably coupled to the fan, the engine core being disposed downstream of the fan and including a core housing, through which passes a core air flow portion of the duct air flow. An afterburner is disposed in the inlet air duct and downstream of the engine core, and a heat exchanger disposed in the inlet air duct.
In accordance with another aspect of the present disclosure, a nozzle assembly is provided for a flight vehicle having an engine. The nozzle assembly comprises a cowl in fluidic communication with the engine, the cowl including a cowl internal surface defining a cowl orifice, and a plug defining a primary thrust surface, wherein the plug is supported relative to the cowl so that a portion of the primary thrust surface is disposed within the cowl orifice, wherein the primary thrust surface of the plug and the cowl internal surface are spaced to define a throat. An actuator is coupled to at least one of the cowl or the plug, and is configured to generate relative movement between the cowl and the plug, thereby to modify the throat.
In accordance with a further aspect of the present disclosure, a method is provided of controlling thrust to a flight vehicle having an engine and an airframe. The method comprises providing a nozzle assembly comprising a cowl in fluidic communication with the engine, the cowl including a cowl internal surface defining a cowl orifice, and a plug defining a primary thrust surface, wherein the plug is supported by the airframe relative to the cowl so that a portion of the primary thrust surface is disposed within the cowl orifice, wherein the primary thrust surface of the plug and the cowl internal surface are spaced to define a throat. The method further comprises generating relative movement between the cowl and the plug, thereby to modify the throat.
The features, functions, and advantages that have been discussed can be achieved independently in various examples or may be combined in yet other examples further details of which can be seen with reference to the following description and drawings.
The novel features believed characteristic of the illustrative examples are set forth in the appended claims. The illustrative examples, however, as well as a preferred mode of use, further objectives and advantages thereof, will best be understood by reference to the following detailed description of illustrative examples of the present disclosure when read in conjunction with the accompanying drawings, wherein:
The figures and the following description illustrate specific examples of the claimed subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described or shown herein, embody the principles of the examples and are included within the scope of the examples. Furthermore, any examples described herein are intended to aid in understanding the principles of construction, operation, or other features of the disclosed subject matter, and are to be construed as being without limitation to such specifically recited examples and conditions. As a result, the inventive concept(s) is not limited to the specific examples described below, but by the claims and their equivalents.
Examples of a turbine engine for a high speed flight vehicle described herein provide cooling to permit operation of the flight vehicle at higher speeds. A heat exchanger is used to cool air passing through an inlet duct, a core housing, specific components of an engine core, and/or a liner of the duct adjacent an afterburner, thereby preventing the temperature of the components from reaching thermal limits. As a result, the turbine engine may continue operation without throttle reduction, thereby increasing the upper end of the range at which the flight vehicle travels.
In this example, the flight vehicle 102 includes a turbine engine 100, a wing 106, a tail 108, and a nose cap 110. The turbine engine 100 is the primary source of propulsion for the flight vehicle 102. During operation of the flight vehicle 102 above Mach 3, or in hypersonic flight (e.g., the flight vehicle 102 moves at hypersonic speeds of Mach 5 and above), the embodiments described herein prevent portions of the turbine engine 100 from being heated to temperatures that are near or exceed thermal limits for the materials used in the turbine engine 100.
In the examples illustrated at
The turbine engine 100 further includes an engine core 122 for producing propulsion from jet core efflux. The engine core 122 is disposed in a center portion of the inlet air duct 112, is operably coupled to the fan 120, and is located downstream of the fan 120. The engine core 122 includes a core housing 124, which divides the duct air flow 118 into a core air flow 126, which passes through the core housing 124, and a bypass air flow 128, which passes around the core housing 124. An afterburner 130 is disposed in the inlet air duct 112 and downstream of the engine core 122 to selectively provide additional thrust to the flight vehicle 102. A portion of the inlet air duct 112 surrounding and downstream of the afterburner 130 includes an afterburner liner 132 for thermal protection of a downstream end of the inlet air duct 112.
The turbine engine 100 includes cooling to mitigate high temperatures associated with operation of the flight vehicle 102. In the example illustrated at
The heat exchanger 140 may be located in different positions within the turbine engine 100, and/or may be provided in different sizes, to provide the desired cooling effect. In
Additionally,
In additional examples illustrated in
As best shown in
With continued reference to
As shown in
The plug 230 is positioned relative to the cowl 210 so that a portion of the primary thrust surface 232 is disposed within the cowl orifice 218. The primary thrust surface 232 and the cowl internal surface 216 are spaced to define therebetween a throat 242. The area of the throat 242, as well as the shapes of the primary thrust surface 232 and cowl internal surface 216, influence the direction and magnitude of thrust produced by the nozzle assembly 200.
The cowl 210 and plug 230 are movable relative to each other, thereby to optimize thrust for a given speed of the flight vehicle 102. In the embodiment shown in
Relative movement between the cowl 210 and the plug 230 will change the thrust characteristics produced by the nozzle assembly 200. For example, regions of the cowl 210 and plug 230 that are nearest each other will form the throat 242. These regions will change as the cowl 210 and plug 230 move relative to each other. Accordingly, the respective contours of the cowl 210 and plug 230 will influence the size, location, angle, and cross-sectional area of the throat 242, thereby impacting thrust characteristics. For example, the cross-sectional area of the throat 242 is a primary control for the propulsion system. Throat location and angle also affect flow for the rest of the nozzle assembly 200, thereby affecting thrust efficiency. Still further, in some examples the contours of the cowl 210 and plug 230 influence the location of the throat 242, which affects the amount of internal expansion of the nozzle assembly 200. Control over the amount of internal expansion is a design factor used to produce high nozzle efficiency over a broad range of Mach numbers. For example, low internal expansion is advantageous subsonic and transonic flight speeds, while high internal expansion is advantageous for supersonic and hypersonic speeds. Accordingly, the ability to produce relative movement between the cowl 210 and the plug 230 allows the nozzle assembly 200 to optimize throat size, location, angle, and cross-sectional area for a particular flight speed, thereby expanding the speed range of the flight vehicle 102.
While the examples of
In some examples, the nozzle assembly 200 includes a nozzle cooling system 250 that primarily reduces temperature at the nozzle assembly 200. Additionally, some examples of the nozzle cooling system 250 also influence a shape of the exhaust plume, thereby altering characteristics of the thrust generated by the nozzle assembly 200.
More specifically, the nozzle cooling system 250 includes a coolant source 252 that is thermally coupled to the primary thrust surface 232. The coolant source 252 may be ambient or bypass air, fluid from a thermal management system provided on the flight vehicle 102, or fluid from any other sub-system provided on the flight vehicle. For example, the coolant may be fuel, water, air, or any other fluid used on or available to the flight vehicle. In some examples, the coolant may be a supercritical fluid, such as supercritical carbon dioxide.
In the example shown in
In the examples illustrated in
In the illustrated examples, a controller 260 is provided to control operation of the nozzle assembly 200. For example, the controller 260 is operably coupled to the coolant regulator 253 to control the coolant flow rate as desired. While the specific hardware implementation of the controller 260 is subject to design choices, one particular example includes one or more processors coupled with a current driver. The one or more processors may include any electronic circuits and/or optical circuits that are able to perform the functions described herein. For example, the processor(s) may perform any functionality described herein for controller 260. The processor(s) may include one or more Central Processing Units (CPU), microprocessors, Digital Signal Processors (DSPs), Application-specific Integrated Circuits (ASICs), Programmable Logic Devices (PLD), control circuitry, etc. Some examples of processors include INTEL® CORE™ processors, Advanced Reduced Instruction Set Computing (RISC) Machines (ARM®) processors, etc.
Any of the various elements shown in the figures or described herein may be implemented as hardware, software, firmware, or some combination of these. For example, an element may be implemented as dedicated hardware. Dedicated hardware elements may be referred to as “processors”, “controllers”, or some similar terminology. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which may be shared. Moreover, explicit use of the term “processor” or “controller” should not be construed to refer exclusively to hardware capable of executing software, and may implicitly include, without limitation, digital signal processor (DSP) hardware, a network processor, application specific integrated circuit (ASIC) or other circuitry, field programmable gate array (FPGA), read only memory (ROM) for storing software, random access memory (RAM), non-volatile storage, logic, or some other physical hardware component or module.
Also, an element may be implemented as instructions executable by a processor or a computer to perform the functions of the element. Some examples of instructions are software, program code, and firmware. The instructions are operational when executed by the processor to direct the processor to perform the functions of the element. The instructions may be stored on storage devices that are readable by the processor. Some examples of the storage devices are digital or solid-state memories, magnetic storage media such as a magnetic disks and magnetic tapes, hard drives, or optically readable digital data storage media.
According to a first example of the subject matter disclosed herein, a turbine engine for a high speed flight vehicle comprises an inlet air duct having an upstream end for receiving ambient air and a downstream end, the inlet air duct directing a duct air flow from the upstream end to the downstream end, a fan disposed in the inlet air duct, an engine core disposed in the inlet air duct and operably coupled to the fan, the engine core being disposed downstream of the fan and including a core housing, through which passes a core air flow portion of the duct air flow, and an afterburner disposed in the inlet air duct and downstream of the engine core. A heat exchanger is disposed in the inlet air duct.
According to a second example of the subject matter disclosed herein, which second example encompasses the first example above, the heat exchanger is positioned upstream of the fan, and the heat exchanger is configured to absorb heat from an entirety of the duct air flow.
According to a third example of the subject matter disclosed herein, which third example encompasses the first example above, the heat exchanger is positioned upstream of the fan, and the heat exchanger is configured to absorb heat from the core air flow portion of the duct air flow.
According to a fourth example of the subject matter disclosed herein, which fourth example encompasses the first example above, the heat exchanger is positioned between the fan and the engine core, and the heat exchanger is configured to absorb heat from the core air flow portion of the duct air flow.
According to a fifth example of the subject matter disclosed herein, which fifth example encompasses the first example above, the engine core further comprises a low pressure compressor disposed in the core housing and a high pressure compressor disposed in the core housing and located downstream of the low pressure compressor, the heat exchanger is positioned between the low pressure compressor and the high pressure compressor, and the heat exchanger is configured to absorb heat from the core air flow portion of the duct air flow.
According to a sixth example of the subject matter disclosed herein, which sixth example encompasses the first example above, the heat exchanger further comprises at least one spot-cooling heat exchanger disposed within the core housing.
According to a seventh example of the subject matter disclosed herein, which seventh example encompasses the sixth example above, the inlet air duct includes an afterburner liner surrounding the afterburner, and the heat exchanger further comprises a liner cooler positioned upstream of and in longitudinal alignment with the afterburner liner.
According to an eighth example of the subject matter disclosed herein, which eighth example encompasses any one of the first through seventh examples above, a nozzle assembly is provided for a flight vehicle having an engine, the nozzle assembly comprising a cowl in fluidic communication with the engine, the cowl including a cowl internal surface defining a cowl orifice, a plug defining a primary thrust surface, wherein the plug is supported relative to the cowl so that a portion of the primary thrust surface is disposed within the cowl orifice, wherein the primary thrust surface of the plug and the cowl internal surface are spaced to define a throat, and an actuator coupled to at least one of the cowl or the plug, the actuator configured to generate relative movement between the cowl and the plug, thereby to modify the throat.
According to a ninth example of the subject matter disclosed herein, which ninth example encompasses the eighth example above, the nozzle assembly further comprises a cooling system having a source of coolant thermally coupled to the primary thrust surface of the plug.
According to a tenth example of the subject matter disclosed herein, which tenth example encompasses the ninth example above, the primary thrust surface is formed by a plug wall having a plug wall interior surface and a plug wall exterior surface, wherein the plug wall exterior surface forms the primary thrust surface of the plug.
According to an eleventh example of the subject matter disclosed herein, which eleventh example encompasses the tenth example above, the plug wall is impervious, and the cooling system directs coolant onto the plug wall interior surface.
According to a twelfth example of the subject matter disclosed herein, which twelfth example encompasses the tenth example above, the plug wall defines perforations extending from the plug wall interior surface to the plug wall exterior surface, and in which the cooling system directs coolant to the plug wall interior surface, through the perforations, and onto the plug wall exterior surface.
According to a thirteenth example of the subject matter disclosed herein, which thirteenth example encompasses the twelfth example above, the cooling system comprises a coolant regulator configured to adjust a coolant flow rate at which coolant is supplied to the plug from the coolant source.
According to a fourteenth example of the subject matter disclosed herein, which fourteenth example encompasses the twelfth example above, the perforations comprise rectilinear perforation profiles.
According to a fifteenth example of the subject matter disclosed herein, which fifteenth example encompasses the twelfth example above, the perforations comprise curvilinear perforation profiles.
According to a sixteenth example of the subject matter disclosed herein, which sixteenth example encompasses the twelfth example above, the perforations comprise both rectilinear perforation profiles and curvilinear perforation profiles.
According to a seventeenth example of the subject matter disclosed herein, which seventeenth example encompasses the ninth example above, the coolant source comprises bypass air.
According to an eighteenth example of the subject matter disclosed herein, which eighteenth example encompasses the eighth example above, the plug is stationary and the cowl is movable relative to the plug.
According to a nineteenth example of the subject matter disclosed herein, which nineteenth example encompasses the eighth example above, the cowl is stationary and the plug is movable relative to the cowl.
According to a twentieth example of the subject matter disclosed herein, which twentieth example encompasses the eighth example above, both the cowl and the plug are movable.
According to a twenty-first example of the subject matter disclosed herein, which twenty-first example encompasses the eighth example above, the relative movement between the cowl and the plug is translation.
According to a twenty-second example of the subject matter disclosed herein, which twenty-second example encompasses the twenty-first example above, the translation is in a direction that is parallel to a longitudinal axis of an airframe of the flight vehicle.
According to a twenty-third example of the subject matter disclosed herein, which twenty-third example encompasses the twenty-first example above, the translation is in a direction that is perpendicular to a longitudinal axis of an airframe of the flight vehicle.
According to a twenty-fourth example of the subject matter disclosed herein, which twenty-fourth example encompasses the twenty-first example above, the translation is at an angle relative to a longitudinal axis of an airframe of the flight vehicle.
According to a twenty-fifth example of the subject matter disclosed herein, which twenty-fifth example encompasses the eighth example above, the relative movement between the cowl and the plug is angular rotation.
According to a twenty-sixth example of the subject matter disclosed herein, which twenty-sixth example encompasses the eighth example above, the primary thrust surface of the plug comprises a partial-axisymmetric shape.
According to a twenty-seventh example of the subject matter disclosed herein, which twenty-seventh example encompasses the twenty-sixth example above, the plug further comprises a plug base coupled to an airframe of the flight vehicle.
According to a twenty-eighth example of the subject matter disclosed herein, which twenty-eighth example encompasses the twenty-sixth example above, the partial-axisymmetric shape is a partial ellipsoid shape.
According to a twenty-ninth example of the subject matter disclosed herein, which twenty-ninth example encompasses the eighth example above, the primary thrust surface of the plug comprises a partial prism shape.
According to a thirtieth example of the subject matter disclosed herein, which thirtieth example encompasses any one of the first through twenty-ninth examples above, a flight vehicle, comprises an airframe, an inlet duct coupled to the airframe, an engine disposed in the inlet duct, and a nozzle assembly disposed downstream of the engine. The nozzle assembly comprises a cowl in fluidic communication with the engine, the cowl including a cowl internal surface defining a cowl orifice, and a plug defining a primary thrust surface, wherein the plug is supported by the airframe relative to the cowl so that a portion of the primary thrust surface is disposed within the cowl orifice, wherein the primary thrust surface of the plug and the cowl internal surface are spaced to define a throat. An actuator is coupled to at least one of the cowl or the plug, and is configured to generate relative movement between the cowl and the plug, thereby to modify the throat.
According to a thirty-first example of the subject matter disclosed herein, which thirty-first example encompasses any one of the first through thirtieth examples above, a nozzle assembly is provided for a flight vehicle having an engine and an airframe. The nozzle assembly comprises a cowl in fluidic communication with the engine, the cowl including a cowl internal surface defining a cowl orifice. The nozzle assembly further comprises a plug defining a primary thrust surface, wherein the plug is supported by the airframe relative to the cowl so that a portion of the primary thrust surface is disposed within the cowl orifice, wherein the primary thrust surface of the plug and the cowl internal surface are spaced to define a throat, the primary thrust surface comprising a partial axi-symmetrical shape. An actuator is coupled to at least one of the cowl or the plug, the actuator configured to generate relative movement between the cowl and the plug, thereby to modify the throat, and a coolant source is thermally coupled to the primary thrust surface of the plug.
According to a thirty-second example of the subject matter disclosed herein, which thirty-second example encompasses any one of the first through thirty-first examples above, a method of providing thrust to a flight vehicle that has an engine and an airframe comprises providing a nozzle assembly. The nozzle assembly comprises a cowl in fluidic communication with the engine, the cowl including a cowl internal surface defining a cowl orifice, and a plug defining a primary thrust surface, wherein the plug is supported by the airframe relative to the cowl so that a portion of the primary thrust surface is disposed within the cowl orifice, wherein the primary thrust surface of the plug and the cowl internal surface are spaced to define a throat. The method further comprises generating relative movement between the cowl and the plug, thereby to modify the throat.
According to a thirty-third example of the subject matter disclosed herein, which thirty-third example encompasses the thirty-second example above, the method further comprises cooling the primary thrust surface of the plug.
According to a thirty-fourth example of the subject matter disclosed herein, which thirty-fourth example encompasses the thirty-second example above, cooling the primary thrust surface of the plug comprises providing coolant to a plug wall exterior surface.
According to a thirty-fifth example of the subject matter disclosed herein, which thirty-fifth example encompasses the thirty-fourth example above, the method further comprises controlling a flow rate of the coolant to the plug wall exterior surface so that the coolant is injected into exhaust gas flow from the nozzle assembly.
Although specific examples were described herein, the scope is not limited to those specific examples. Rather, the scope is defined by the following claims and any equivalents thereof.
This application claims priority to, and the benefit of, U.S. Provisional Patent Application No. 63/127,304 filed Dec. 18, 2020, which is hereby incorporated by reference in its entirety.
Number | Date | Country | |
---|---|---|---|
63127304 | Dec 2020 | US |