Patent Description:
At least certain vehicles generate a relatively large amount of heat during operation. For example, at least certain aircraft generate a relatively large amount of heat during operation of its thrust generating systems, such as during operation of one or more gas turbine engines, electric motors and generators, etc., as well as through other flight-enabling accessory systems, such as hydraulic systems, electronic systems, etc..

In order to reject a desired amount of such heat, certain aircraft include ram air coolers, externally mounted coolers, etc. However, such coolers may create additional drag on the aircraft, such as an additional amount of parasitic drag. Accordingly, an aircraft or other vehicle including a thermal management system having one or more features for rejecting heat without increasing a drag on the vehicle would be useful.

<CIT> discloses an aircraft with a fuselage that comprises a framework structure. The framework having at least one hollow frame that is integrally formed in one piece and comprises fiber reinforced polymers, the at least one hollow frame defining an integrated ventilation air duct that is adapted for guiding ventilation air into the aircraft.

<CIT>, discloses a liquid coolant heat exchange system for use in semimonocoque aircraft. The system includes an arcuate planar heat sink fixed along a radius of curvature R1 by forming members, a flexible arcuate planar spreader plate having a radius R2, such that R1 >R2, a heat exchange tube for transferring heat from the liquid coolant to the heat sink and means for attaching the spreader plate to the forming members to hold the spreader plate in contact with the heat sink.

Claim <NUM> defines a vehicle and claim <NUM> defines a method Preferred embodiments are defined by the dependent claims.

Referring now to the drawings, wherein identical numerals indicate the same elements throughout the Figs. , <FIG> provides a top view of an exemplary aircraft <NUM> as may incorporate various embodiments of the present disclosure. <FIG> provides a port side <NUM> view of the aircraft <NUM> as illustrated in <FIG>. As shown in <FIG> collectively, the aircraft <NUM> defines a longitudinal direction L that extends generally along a longitudinal centerline <NUM> of the aircraft <NUM>, a vertical direction V, a transverse direction T, a forward end <NUM>, and an aft end <NUM>.

Moreover, the aircraft <NUM> includes various structures, such as a fuselage <NUM> extending longitudinally from the forward end <NUM> of the aircraft <NUM> towards the aft end <NUM> of the aircraft <NUM>, and a pair of wings <NUM>, or rather, a first wing 22A and a second wing 22B. The first wing 22A extends outwardly from the fuselage <NUM> generally along the transverse direction T with respect to the longitudinal centerline <NUM>, from the port side <NUM> of the fuselage <NUM>. Further, the second wing 22B similarly extends outwardly from the fuselage <NUM>, generally along the transverse direction T with respect to the longitudinal centerline <NUM>, from a starboard side <NUM> of the fuselage <NUM>. Each of the wings 22A, 22B for the exemplary embodiment depicted includes one or more leading edge flaps <NUM> and one or more trailing edge flaps <NUM>.

Referring still to the exemplary aircraft <NUM> of <FIG>, the aircraft <NUM> further includes additional structures, such as a vertical stabilizer <NUM> having a rudder flap <NUM> for yaw control, and a pair of horizontal stabilizers <NUM>, each having an elevator flap <NUM> for pitch control. Additionally, the aircraft <NUM> may include structures such as fairings, externally mounted sponsons or pods, tail cones, engine nacelles, etc..

However, it should be appreciated that in other exemplary embodiments of the present disclosure, the aircraft <NUM> may additionally or alternatively include any other suitable configuration of stabilizers or structures that may or may not extend directly along the vertical direction V or horizontal/transverse direction T. In addition, alternative stabilizers or structures may be any suitable shape, size, configuration, or orientation while remaining within the scope of the present subject matter.

Each of the above structures, such as the fuselage <NUM>, wings 22A, 22B, and stabilizers <NUM>, <NUM>, additionally includes an outer skin <NUM>. The outer skin <NUM> may be formed of a thin sheet metal, composite material, thermally-conductive composite material, ceramic material, and/or other suitable material.

The exemplary aircraft <NUM> of <FIG> also includes a propulsion system. The exemplary propulsion system depicted includes a plurality of aircraft engines, at least one of which mounted to each of the pair of wings 22A, 22B. Specifically, the plurality of aircraft engines includes a first aircraft engine <NUM> mounted to the first wing 22A and a second aircraft engine <NUM> mounted to the second wing 22B. In at least certain exemplary embodiments, the aircraft engines <NUM>, <NUM> may be configured as turbofan jet engines suspended beneath the wings 22A, 22B in an under-wing configuration.

Alternatively, however, in other exemplary embodiments any other suitable aircraft engine may be provided. For example, in other exemplary embodiments the first and/or second aircraft engines <NUM>, <NUM> may alternatively be configured as turbojet engines, turboshaft engines, turboprop engines, etc. Further, in still other exemplary embodiments, the propulsion system may include one or more electric, or hybrid-electric, aircraft engines (e.g., electric fans). In any of the above embodiments, the engines may be arranged in any suitable manner (e.g., stabilizer-mounted, fuselage-mounted, etc.).

Further, for the embodiment shown the aircraft <NUM> additionally includes a thermal management system <NUM>. As is depicted in phantom, the thermal management system <NUM> includes a heat exchanger assembly <NUM> positioned adjacent to, and in thermal communication with, an inside surface of the outer skin <NUM> of the aircraft <NUM> (as will be explained in more detail below). Moreover, the thermal management system <NUM> includes a thermal bus <NUM> and at least one heat source exchanger <NUM>. The heat source exchanger <NUM> may be located within, proximal to, or otherwise in thermal communication with, an aircraft engine (e.g., engines <NUM>, <NUM>), auxiliary power unit, energy storage unit, environmental control system, electrical power conditioner, aircraft avionics unit, payload avionics unit, etc. More specifically, the exemplary thermal management system <NUM> depicted includes a plurality of heat source exchangers <NUM>, each of the plurality of heat source exchangers <NUM> thermally coupled to a heat source of one of the engines <NUM>, <NUM> (e.g., a lubrication oil heat source, a cooled cooling air heat source, etc.). The thermal bus <NUM> may transport a thermal fluid from the heat source exchangers <NUM> to the heat exchanger assembly <NUM> located adjacent to, and in thermal communication with, the inside surface of the outer skin <NUM> for rejecting heat from the heat sources of the engines <NUM>, <NUM> using the heat exchanger assembly <NUM>. In such a manner, the thermal management system <NUM> may utilize an ambient airflow over an outer surface of the outer skin <NUM> reject heat from certain heat sources of the aircraft <NUM>.

The "thermal fluid" may be any suitable fluid for transferring thermal energy. For example, in at least certain exemplary embodiments the thermal fluid may be air (which has the benefit of being abundant and can recharge cooling system to offset leakages); gasses other than air; liquids such as water, water-glycol mixtures (to, e.g., prevent freezing), oils including lubrication oil and thermal oils such as Syltherm, Dowtherm, etc.; fuel (allowing for, e.g., fuel cooling through aircraft skin); refrigerants (including CO2, supercritical CO2, and/or any other refrigerant, such as those having an "R" designation from the American Society of Heating, Refrigerating and Air-Conditioning Engineers).

Referring now to <FIG>, a partial, schematic, cutaway view of a section of the fuselage <NUM> of the aircraft <NUM><NUM> described above with reference to <FIG> is provided. As is shown, the fuselage <NUM> includes the outer skin <NUM>, as well as a frame assembly <NUM> having a plurality of structural members. The fuselage <NUM> defines a circumferential direction C extending about the longitudinal centerline <NUM> of the aircraft <NUM>. Further, the outer skin <NUM> defines an outside surface <NUM> exposed to the ambient airflow over the aircraft <NUM> and an inside surface <NUM>. The plurality of structural members of the frame assembly <NUM> extend from the inside surface <NUM> of the outer skin <NUM>. For the embodiment shown, the plurality of structural members of the frame assembly <NUM> includes a plurality of frame members <NUM> extending about the longitudinal centerline <NUM> in the circumferential direction C and spaced from one another along the longitudinal direction L. Additionally, the plurality structural members of the frame assembly <NUM> includes a plurality longitudinal stiffeners <NUM> extending generally along the longitudinal direction L. The plurality of longitudinal stiffeners <NUM> are spaced from one another along the circumferential direction C.

Referring now to <FIG> a schematic, cross-sectional view of the fuselage <NUM> of <FIG> is provided, taken generally along Line <NUM>-<NUM> of <FIG>. As was noted above, the fuselage <NUM> generally includes the frame assembly <NUM> having the plurality structural members extending generally from the inside surface <NUM> of the outer skin <NUM>. The plurality structural members includes a first structural member, a second structural member, a third structural member, and a fourth structural member. For the embodiment shown, the first structural member is a first longitudinal stiffener 116A, the second structural member is a second longitudinal stiffener 116B, the third structural member is a third longitudinal stiffener 116C, and the fourth structural member is a fourth longitudinal stiffener 116D. Each of these longitudinal stiffeners <NUM> extends generally along the longitudinal direction L and is spaced from one another generally along the circumferential direction C.

Moreover, as will be appreciated, the thermal management system <NUM> of the aircraft <NUM>, briefly introduced above, includes the heat exchanger assembly <NUM> positioned adjacent to, and in thermal communication with, the inside surface <NUM> of the outer skin <NUM>, and further positioned between the first structural member and the second structural member, or more specifically, between the first longitudinal stiffener 116A and the second longitudinal stiffener 116B.

It will be appreciated, that as used herein, the term "positioned adjacent to, and in thermal communication with" refers to one component either contacting the other component, of being separated only by a small number of intermediate components and/or air gaps not substantially impeding a thermal transfer from one component to the other. For example, as used herein, the term "positioned adjacent to, and in thermal communication with" may allow for, e.g., intermediate thermally conductive tapes or other adhesives, as well as other thermally-conductive compounds (such as wax, grease, etc.) between two components (see, e.g., <FIG>) and/or air gaps resulting from limitations of commercially practical manufacturing methods (such as air gaps less than about <NUM> inch, such as less than about <NUM> inches, such as less than about <NUM> inches).

Referring still particularly to the exemplary embodiment shown in <FIG>, the heat exchanger assembly <NUM> generally includes a cooling unit and a structural backing <NUM>. For the embodiment shown, the cooling unit is a cooling tube <NUM>. The structural backing <NUM> mounts the cooling tube <NUM> in position adjacent to, and in thermal communication with, the inside surface <NUM> of the outer skin <NUM>. In such a manner, the cooling tube <NUM> may transfer heat from a thermal fluid flowing therethrough (received from, e.g., the thermal bus <NUM>) across the outer skin <NUM> to an ambient airflow over the outer skin <NUM>.

It will be appreciated, however, that in other embodiments, the cooling unit of the heat exchanger assembly <NUM> may be, e.g., a plate defining one or more internal passages, with the the plate having a geometry that is conformal to and attached to the inside surface <NUM> of the outer skin <NUM>.

More specifically, referring still to the embodiment of <FIG>, the heat exchanger assembly <NUM> is coupled to a first structural member, a second structural member, or both. Particularly for the embodiment of <FIG>, the structural backing <NUM> is mounted to the first longitudinal stiffener 116A, the second longitudinal stiffener 116B, or both. In particular, for the embodiment shown, the structural backing <NUM> is mounted to both the first longitudinal stiffener 116A and the second longitudinal stiffener 116B.

Further, for the embodiment shown, the structural backing <NUM> utilizes a geometry of the first longitudinal stiffener 116A and second longitudinal stiffener 116B to mount the thermal heat exchanger assembly <NUM>. For example, referring now also to <FIG>, providing a close-up, schematic view of the heat exchanger assembly <NUM> mounted to the outer skin <NUM>, it will be appreciated that the outer surface of the fuselage <NUM> defines a generally circular or ovular shape. As such, the local region of the outer skin <NUM> depicted in <FIG> and <FIG> generally defines an arcuate shape. The longitudinal stiffeners <NUM> extend generally from the inside surface <NUM> of the outer skin <NUM> in a generally perpendicular manner, such that the longitudinal stiffeners <NUM> are not parallel to one another.

More particularly, the first and second longitudinal stiffeners 116A, 116B are slanted towards one another as they extend from the inside surface <NUM> of the outer skin <NUM>. Referring particularly to <FIG>, the first longitudinal stiffener 116A defines a first reference line <NUM> extending away from the inside surface <NUM> of the outer skin <NUM> and the second longitudinal stiffener 116B defines a second reference line <NUM> extending away from the inside surface <NUM> of the outer skin <NUM>. The first and second reference lines <NUM>, <NUM>, which are each straight lines, are not parallel to one another, and instead converge towards one another such that they contact one another.

Further, referring particularly to <FIG>, the first and second longitudinal stiffeners 116A, 116B define a separation distance <NUM> between their distal ends <NUM> (which is greater than a separation distance at their respective bases proximate the inside surface <NUM> of the outer skin <NUM>; not labeled). Further, the structural backing <NUM> defines a length <NUM>. The length <NUM> of the structural backing <NUM> is greater than the separation distance <NUM> defined between the distal ends <NUM> of the first and second longitudinal stiffeners 116A, 116B.

In such a manner, the structural backing <NUM> of the heat exchanger assembly <NUM> may be fixed at least partially between the first longitudinal stiffener 116A and second longitudinal stiffener 116B for mounting the heat exchanger assembly <NUM>. More specifically, the structural backing <NUM> may be wedged into place to mount the heat exchanger assembly <NUM>.

It will be appreciated, however, that in other exemplary embodiments, the structural backing <NUM> instead be fixed to the longitudinal stiffeners <NUM>, or other structural features (such as the frame members <NUM>) of the frame assembly <NUM> of the fuselage <NUM> (or other structure of the aircraft <NUM>) in any other suitable manner, such as through a suitable bolting, clamping, bonding, or other suitable attachment means.

Referring still to <FIG>, it will be appreciated that for the embodiment shown, the thermal management system <NUM> further includes a plurality of heat exchanger assemblies <NUM>. In particular, the above-described heat exchanger assembly <NUM> is a first heat exchanger assembly 102A, and the thermal management system <NUM> further includes a second heat exchanger assembly 102B and a third heat exchanger assembly 102C. The second heat exchanger assembly 102B is positioned adjacent to, and in thermal communication with, the inside surface <NUM> outer skin <NUM> at a location between the second longitudinal stiffener 116B and third longitudinal stiffener 116C, and the third heat exchanger assembly 102C is positioned adjacent to, and in thermal communication with, the inside surface <NUM> of the outer skin <NUM> at a location between the third longitudinal stiffener 116C and the fourth longitudinal stiffener 116D. For the exemplary embodiment shown, the first exchanger assembly is fluidly coupled to the second heat exchanger assembly 102B through a first jumper line <NUM>, and similarly, the third heat exchanger assembly 102C is fluidly coupled to the second heat exchanger assembly 102B through a second jumper line <NUM>. In such a manner, it will be appreciated that the first heat exchanger assembly 102A, the second heat exchanger assembly 102B, and the third heat exchanger assembly 102C are arranged in serial flow order.

However, in other exemplary embodiments, one or more of the first heat exchanger assembly 102A, the second heat exchanger assembly 102B, and the third heat exchanger assembly 102C may instead be arranged in a parallel flow order or a combination of parallel and series flow order. Further, in other exemplary embodiments, the thermal management system <NUM> may include any suitable number of heat exchanger assemblies <NUM>, such as one, two, four, etc..

Further, referring briefly to <FIG>, a plan view of a portion of the first heat exchanger assembly 102A is depicted. Specifically, <FIG> depicts the cooling tube <NUM> of the first heat exchanger assembly 102A. The structural backing <NUM> of the first heat exchanger assembly 102A is removed for clarity. As is shown, the cooling tube <NUM> of the first heat exchanger assembly 102A extends in a serpentine path in order to, e.g., maximize a contact with the inside surface <NUM> of the outer skin <NUM>. The cooling tube <NUM> defines an inlet <NUM> and an outlet <NUM>. The inlet <NUM> may be in flow communication with the thermal bus <NUM> (see, e.g., <FIG>), and the outlet <NUM> may be in flow communication with, e.g., the first jumper line <NUM>.

For the embodiment depicted in <FIG>, it will be appreciated that the first heat exchanger assembly 102A is positioned generally between the first longitudinal stiffener 116A and the second longitudinal stiffener 116B, as well as between a first frame member 114A and a second frame member 114B, spaced along the longitudinal direction L.

Moreover, referring now to <FIG>, a cross-sectional view of a portion of the fuel cooling tube <NUM> of the first heat exchanger assembly 102A is depicted, taken along Line <NUM>-<NUM> in <FIG>. As is shown, the portion of the cooling tube <NUM> depicted extends along a lengthwise direction LW and defines a first side <NUM> proximate the inside surface <NUM> of the outer skin <NUM> and a second side <NUM> opposite the first side <NUM>. For the embodiment shown, the cooling tube <NUM> defines a plurality of nonlinear features spaced along the lengthwise direction LW of the first side <NUM>. The nonlinear features may assist with creating increased heat transfer between the thermal fluid flowing through the cooling tube <NUM> and the outer skin <NUM> of the aircraft <NUM>, and thus between the thermal fluid flowing through the cooling tube <NUM> and an ambient airflow over the outer surface of the aircraft <NUM>.

For the embodiment of <FIG>, the nonlinear features include a plurality of dimples <NUM> having a generally semicircular shape. However, in other exemplary embodiments, any other suitable nonlinear features may be provided to enhance thermal transfer. For example, In other exemplary embodiments, the cooling tube <NUM> may include any suitable combination of turbulators, dimples, grooves (such as spiral grooves), etc..

Notably, for the embodiment of <FIG>, each of the plurality of nonlinear features are positioned on the first side <NUM> of the cooling tube <NUM> proximate the inside surface <NUM>. It will be appreciated, however, that in other embodiments, the cooling tube <NUM> may have any other suitable non-linear feature arranged in any suitable manner, and positioned at any other suitable location. For example, in other embodiments, the cooling tube <NUM> may further include nonlinear features on the second side <NUM> of the cooling tube <NUM>, or elsewhere.

It will be appreciated, that as used herein, the term "nonlinear feature," with reference to the cooling tube <NUM>, refers to any section, or portion, of the cooling tube <NUM> that does not extend substantially linearly along the lengthwise direction LW of the cooling tube <NUM>.

In order to form the cooling tube <NUM> having such nonlinear features, the cooling tube may be additively manufactured, also known as <NUM>-D printed. However, in other embodiments, the cooling tube <NUM> may not be additively manufactured, and instead may be formed in any suitable manner, such as by metal sheet stamping and diffusion bonding.

Referring now to <FIG>, a close-up, cross-sectional view of a heat exchanger assembly <NUM> in accordance with an embodiment of the present disclosure is provided. The heat exchanger assembly <NUM> of <FIG> is depicted in the same viewing plane as the heat exchanger assembly <NUM> described above with reference to <FIG>.

In certain embodiments, the heat exchanger assembly <NUM> of <FIG> may be configured in substantially the same manner as the exemplary heat exchanger assembly <NUM> described above with reference to <FIG>. For example, as is shown, the heat exchanger assembly <NUM> generally includes a structural backing <NUM> and a cooling unit. For the embodiment depicted, the cooling unit is a cooling tube <NUM>. The cooling tube <NUM> is mounted by the structural backing <NUM> adjacent to, and in thermal communication with, the inside surface <NUM> of the outer skin <NUM> of the vehicle. Further, the cooling tube <NUM> is configured to flow a thermal fluid therethrough to transfer heat from the thermal fluid through the outer skin <NUM> of the vehicle to an ambient airflow over the outer skin <NUM> of the vehicle.

As will be appreciated from the view of <FIG>, the inside surface <NUM> of the outer skin <NUM> the vehicle defines a nonplanar geometry, such as an arcuate geometry. In order to maximize a heat transfer from the thermal fluid through the cooling tube <NUM> to the outer skin <NUM> of the vehicle, the cooling tube <NUM> is configured to form to a geometry of the inside surface <NUM> of the outer skin <NUM>. As such, the cooling tube <NUM> is formed of a flexible or semirigid material.

For example, in the embodiment depicted, the cooling tube <NUM> is formed of a composite having an additive for increased thermal conductivity. For example, the cooling tube <NUM> may be formed of a filled polymer material. The term "filled polymer" refers to a natural or synthetic polymeric material having thermally conductive particles therein to allow a desired amount of heat transfer across the material. For example, the cooling tube <NUM> may be formed of a polymer, such as rubber, having aluminum particles, iron particles, magnesium oxide particles, aluminum nitride particles, boron nitride particles, diamond dust, carbon dust, carbon nanotubes, carbon fiber filaments, or a combination thereof, therein. Further, it will be appreciated that as used herein, that the term "flexible or semi-rigid," as used to describe the cooling tube <NUM>, refers to being formed of a material capable of at least partially elastically deforming to conform to a geometry of the inside surface <NUM> of the outer skin <NUM> when the heat exchanger assembly <NUM> is installed.

As such, the cooling tube <NUM> may be formed of a material capable of conforming to the geometry of the inside surface <NUM> of the skin <NUM>, while still being capable of transferring a desired amount of heat from the thermal fluid flowing therethrough to the skin <NUM>.

Further, referring still to <FIG>, in order to provide the desired contact between the cooling tube <NUM> and the inside surface <NUM> of the outer skin <NUM>, the heat exchanger assembly <NUM> further includes an inflatable member <NUM> operable with the cooling tube <NUM> to press the cooling tube <NUM> towards the inside surface <NUM> of the outer skin <NUM>. Specifically, for the embodiment shown, the inflatable member <NUM> is an inflatable bladder positioned at least partially within the cooling tube <NUM>. The inflatable bladder may run lengthwise within cooling tube <NUM> (e.g., along the lengthwise direction LW of the cooling tube <NUM>, as is depicted in <FIG>).

In at least certain exemplary embodiments, the inflatable bladder may receive a compressed gas flow once the heat exchanger assembly <NUM> is installed to press the cooling tube <NUM> towards the inside surface <NUM> of the outer skin <NUM>. In such a manner, it will be appreciated that in at least certain exemplary aspects, inflatable bladder may be at least partially deflated (as is depicted in phantom <FIG> as <NUM>') when the heat exchanger assembly <NUM> is installed, allowing for increased ease of installation. Further, in at least certain exemplary aspects, the inflatable member <NUM> may be deflated during certain operational conditions, non-operational conditions, and/or maintenance activities. Such may protect the outer skin <NUM> and may further allow for increase ease of such maintenance activities.

The pressurized gas flow provided to the inflatable bladder may come from, e.g., an engine bleed, an onboard gas container, a refrigerant bleed from a vapor-compression cycle refrigeration unit, a ground source, etc. The temperature of the pressurized gas flow may be reduced by some means such as a heat exchanger, throttling process, or other precooling means to further assist with a cooling of a thermal fluid through the heat exchanger assembly <NUM>. In at least certain exemplary embodiments, the inflatable bladder may extend substantially along the entire length of the cooling tube <NUM> (e.g., substantially along the entire length between an inlet <NUM> and an outlet <NUM> of the cooling tube <NUM>; see, e.g., <FIG>).

Notably, inflating the inflatable bladder once the heat exchanger assembly <NUM> is installed may further assist with the mounting of the heat exchanger assembly <NUM>, and further wedging the structural backing <NUM> between adjacent longitudinal stiffeners <NUM>.

Referring still <FIG>, it will be appreciated that the thermal management system <NUM> may additionally include certain additional features for further removing heat from the thermal transfer fluid flowing through the cooling tube <NUM>. Specifically, for the embodiment shown, thermal management system <NUM>, or rather, the heat exchanger assembly <NUM>, further defines a cooling air flowpath <NUM> adjacent to, and in thermal communication with, the cooling tube <NUM>. For the embodiment shown, the cooling air flowpath <NUM> is defined by the structural backing <NUM>, the cooling tube <NUM>, the inside surface <NUM> of the outer skin <NUM>, or combination thereof. Specifically, for the embodiment shown, the cooling air flowpath <NUM> is defined by each of the structural backing <NUM>, the cooling tube <NUM>, and the inside surface <NUM> of the outer skin <NUM>. Further, the thermal management system <NUM> comprises a cooling airflow delivery system <NUM> and a cooling airflow exhaust system <NUM>. In at least certain exemplary embodiments, the cooling airflow delivery <NUM> system includes a cooling airflow source <NUM> and a cooling airflow delivery conduit <NUM>. The cooling airflow source <NUM> may be, e.g., a cabin air source or other suitable relatively cool airflow source. Further, the cooling airflow exhaust system <NUM> generally includes a cooling airflow exhaust conduit <NUM> and a cooling airflow sink <NUM>. The cooling airflow sink <NUM> may be, e.g., an exhaust to an ambient location.

Alternatively, in other embodiments, the cooling airflow exhaust <NUM> may be in airflow communication with the cooling airflow source <NUM> through, e.g., an airflow heat exchanger. In such an embodiment, the cooling airflow channels <NUM> may be configured as a closed loop airflow cooling system.

It will be appreciated, however, that in other exemplary embodiments, the heat exchanger assembly <NUM> may have still other suitable configurations. For example, referring now to <FIG>, a heat exchanger assembly <NUM> in accordance with another exemplary embodiment of the present disclosure is provided. In the embodiment of <FIG>, the heat exchanger assembly <NUM> may be configured in substantially the same manner as the heat exchanger assembly <NUM> described above with reference to <FIG>.

For example, the exemplary heat exchanger assembly <NUM> depicted in <FIG> generally includes a structural backing <NUM> and a cooling unit. For the embodiment depicted, the cooling unit is a cooling tube <NUM>. The cooling tube <NUM> is positioned adjacent to, and in thermal communication with, the inside surface <NUM> of the outer skin <NUM> for transferring heat from a thermal fluid flowing through the cooling tube <NUM>, across the outer skin <NUM>, to an ambient airflow over the outer skin <NUM>. Further, the heat exchanger assembly <NUM> depicted in <FIG> includes an inflatable member <NUM> operable with the cooling tube <NUM> to the press the cooling tube <NUM> towards the inside surface <NUM> of the outer skin <NUM>.

However, for the exemplary embodiment of <FIG>, the inflatable member <NUM> is not located within the cooling tube <NUM>, and instead is positioned between the cooling tube <NUM> and the structural backing <NUM>. More specifically, for the embodiment shown, the heat exchanger assembly <NUM> further includes a load applicator <NUM> positioned between the inflatable member <NUM> and the cooling tube <NUM>, as well as a first standoff member <NUM> and a second standoff member <NUM>. For the embodiment shown, the first and second standoff members <NUM>, <NUM> are resilient members, or springs, and extend from the load applicator <NUM> towards inside surface <NUM> of the outer skin <NUM>. For the embodiment shown, the first and second standoff members <NUM>, <NUM> are positioned on opposing sides of the first cooling tube <NUM> (e.g., along the circumferential direction C). The first and second standoff members <NUM>, <NUM> may ensure a desired alignment of the cooling tube <NUM> with the inside surface <NUM><NUM> of the outer skin <NUM>.

It will be appreciated, however, that in other exemplary embodiments, the first and second standoff members <NUM>, <NUM> may be configured in any suitable manner. For example, in other exemplary embodiments, the first and/or second standoff member <NUM>, <NUM> may be configured as a spring, such as a standard helical spring. With one or more of these configurations, the first and second standoff members <NUM>, <NUM> may act to align the heat exchanger assembly <NUM> with the inside surface <NUM> of the outer skin <NUM>.

Further for the embodiment shown, the load applicator <NUM> defines a channel <NUM>, with the inflatable member <NUM> positioned at least partially within the channel <NUM>. The inflatable member <NUM>, as with the inflatable bladder discussed above, is configured to increase in volume when a pressurized airflow is provided thereto. As such, the inflatable member <NUM> may be deflated, as is depicted in phantom <FIG> as <NUM>', during installation of the heat exchanger assembly <NUM>, and subsequently inflated after installation of the heat exchanger assembly <NUM>. The increase in volume of the inflatable member <NUM> may act to both press the cooling tube <NUM> against the inside surface <NUM> of the outer skin <NUM>, to assist with molding the cooling tube <NUM> to the geometry of the inside surface <NUM> of the outer skin <NUM>, and further to assist with installation of the heat exchanger assembly <NUM>. In particular, the inflatable member <NUM> may be deflated during installation to allow for the heat exchanger assembly <NUM> to be moved into position between adjacent structural members (e.g., adjacent longitudinal stiffeners 116A, 116B; see <FIG>) with relative ease, and then subsequently inflated to wedge the structural backing <NUM> in between adjacent structural members (e.g., adjacent longitudinal stiffeners 116A, 116B; see <FIG>).

As is further depicted in <FIG>, the heat exchanger assembly <NUM> additionally includes an adhesive <NUM> between the inside surface <NUM> of the outer skin <NUM> and at least one of the first standoff member <NUM>, the second standoff member <NUM>, or the cooling tube <NUM>. Specifically, for the embodiment shown, the heat exchanger assembly <NUM> includes adhesive <NUM> between each of the inside surface <NUM> of the outer skin <NUM> and the first standoff member <NUM>, the second standoff member <NUM>, and the cooling tube <NUM>. Such may assist with installation of the heat exchanger assembly <NUM> by allowing the heat exchanger assembly <NUM> to temporarily mounted in position using the adhesive <NUM> and to remain in position while, e.g., the inflatable member <NUM> is inflated and the structural backing <NUM> is attached to the structural members of the fuselage <NUM>, e.g., wedged between adjacent first and second longitudinal stiffeners 116A, 116B.

In certain exemplary embodiments, the adhesive <NUM> may be a thermally conductive adhesive. For example, the adhesive <NUM> may be a double-sided tape, glue, etc. The adhesive <NUM> may have a thermal conductivity greater than about <NUM> Watts /meter-Kelvin, such as greater than about <NUM> Watts /meter-Kelvin.

It will further be appreciated that the configuration of <FIG> may further assist with accommodating relative thermal growth and contraction during operation of the aircraft <NUM>. In particular, the adhesive may assist with accommodating relative thermal growth and contraction during operation of the aircraft <NUM>.

Referring now to <FIG>, close-up, cross-sectional views of a heat exchanger assembly <NUM> in accordance with yet an embodiment of the present disclosure are provided.

In particular, it will be appreciated that for the embodiment depicted, the heat exchanger assembly <NUM> includes a structural backing <NUM> extending along a longitudinal direction L between two structural members, and in particular between a first frame member 114A and a second frame member 114B (<FIG>). In addition, the structural backing <NUM> extends across a plurality of structural members arranged substantially perpendicularly to the first and second frame members 114A, 114B, and more specifically, extends across a plurality of longitudinal stiffeners <NUM> (i.e., stiffeners 116A, 116B, 116C for the embodiment depicted in <FIG>).

Referring particularly to <FIG>, the structural backing <NUM> is coupled to the first frame member 114A, the second frame member 114B, or both. Specifically, for the embodiment shown, the structural backing <NUM> is coupled to the first frame member 114A. For the embodiment shown, the structural backing <NUM> is coupled to the first frame member 114A through a mechanical fastener <NUM>. However, in other embodiments, the structural backing <NUM> may be coupled to the first frame member 114A in any other suitable manner.

Further, referring particularly to <FIG>, it will be appreciated that for the exemplary heat exchanger assembly <NUM> depicted, the structural backing <NUM> is shaped to accommodate the various structural members of the structure within which the heat exchanger assembly <NUM> is installed. More specifically, for the embodiment shown the structural backing <NUM> defines a corrugated shape. More specifically still, the structural backing <NUM> includes a plurality of near sections <NUM> defining a first separation distance <NUM> from the inside surface <NUM> of the outer skin <NUM> and a plurality of far sections <NUM> defining a second separation distance <NUM> from the inside surface <NUM> of the outer skin <NUM>. The first separation distance <NUM> is less than the second separation distance <NUM>, such as at least about <NUM>% less, such as at least about <NUM>% less, such as up to about <NUM>% less.

Further for the embodiment depicted, the corrugated shape of the structural backing <NUM> allows for the structural backing <NUM> to hold the cooling unit of the heat exchanger assembly <NUM> in position adjacent to, and in thermal communication with, the inside surface <NUM> of the skin <NUM>. In particular, for the embodiment depicted in <FIG>, the cooling unit of the heat exchanger assembly <NUM> is a cooling bladder <NUM> extending over a plurality of structural members, and in particular extending across longitudinal stiffeners 116A, 116B, 116C for the embodiment depicted in <FIG>. For this embodiment, the near sections <NUM> of the structural backing <NUM> press the cooling bladder <NUM> toward the inside surface <NUM> of the skin <NUM> and the far sections <NUM> allow portions of the cooling bladder <NUM> to extend over the structural members.

Further still for the embodiment depicted, the cooling unit, or cooling bladder <NUM> for the embodiment shown, additionally includes a plurality of inflatable members <NUM> for pressing the cooling bladder <NUM> against the inside surface <NUM> of the skin <NUM>, to increase a heat flux therebetween.

However, in other embodiments, the heat exchanger assembly <NUM> may have still other configurations. For example, referring now to <FIG>, a close-up, cross-sectional view of a heat exchanger assembly <NUM> in accordance with yet another embodiment of the present disclosure is provided. The heat exchanger assembly <NUM> depicted in <FIG> may be configured in a similar manner as the heat exchanger assembly <NUM> of <FIG>. However, for the embodiment depicted, the heat exchanger assembly <NUM> includes a plurality of cooling units, or rather a plurality of cooling bladders <NUM>, with each cooling bladder <NUM> positioned between adjacent structural members, such as between adjacent longitudinal stiffeners 116A, 116B, 116C.

It will be appreciated that although the exemplary thermal management systems <NUM> described above are described with reference to a fuselage <NUM> of an aircraft <NUM>, in other exemplary embodiments the heat exchanger assembly(ies) of the thermal management system <NUM> may additionally or alternatively be positioned adjacent to, and in thermal communication with, an inside surface of a skin of any suitable structures of an aircraft <NUM>. For example, in other exemplary embodiments, the thermal management system <NUM> may include one or more heat exchangers incorporated into a wing of an aircraft <NUM>, a stabilizer of an aircraft <NUM>, or additional structures, such as fairings, externally-mounted sponsons or pods, tail cones, engine nacelles, etc. For example, with respect to the wing configuration, the structural members may be a wing spar, nose ribs, rear ribs, etc. Additionally with such a configuration, the longitudinal and circumferential directions may be relative to the wing structure.

Further, in still other exemplary embodiments, the thermal management system <NUM> may be operable with other vehicles, such as marine vehicles (e.g., boats, submarines, etc.), land vehicles, space vehicles, etc..

In one or more of these embodiments, a heat exchanger assembly may be mounted between structural members that are relatively parallel to one another, such that they do not converge towards one another. In such cases, a structural backing of the heat exchanger assembly may be coupled to one or both of the structural members through any other suitable means, such as by bolting or other mechanical fastening, arrangement of complementary geometries (e.g., hooks, loops, ledges, etc.), adhesives, etc..

It will further be appreciated that although for the embodiments described above the heat exchanger assembly(ies) are described as being a heat sink heat exchanger to transfer heat from a thermal fluid through an outer skin to an ambient flow, in other embodiments, the heat flux may be reversed. For example, with certain configurations, the heat exchanger assembly(ies) of the thermal management system may be configured to absorb heat from the outer skin of the structure of the vehicle to reduce a temperature of the outer skin of the structure of the vehicle. For example, such may be incorporated into a supersonic or hypersonic aircraft to cool an outer skin of a structure of such aircraft.

Further, still, it will be appreciated that although the heat exchanger assemblies described herein are described as having benefits from a thermal management standpoint, in at least certain exemplary embodiments, one or more of the configurations disclosed herein may be configured to dampen vibration in the skin structures, in addition to or in the alternative to the thermal management roles. For example, one or more of the exemplary the cooling units of the heat exchanger assemblies may instead be configured as a dampening unit of a structural dampener assembly. In such a configuration, the structural dampener assembly may be configured in substantially the same manner as one or more of the heat exchanger assembly configurations described above, except that it may not flow a thermal fluid therethrough for effectuating heat transfer with the skin.

Referring now to <FIG>, a method <NUM> of attaching a heat exchanger assembly of a thermal management system to an inside surface of the skin of the vehicle is provided. The heat exchanger assembly and thermal management system may be configured in any suitable manner. For example, in certain exemplary embodiments, the heat exchanger assembly in thermal management system may be configured in accordance with one or more the exemplary embodiments described above with reference to <FIG>. However, in other embodiments, the heat exchanger assembly and thermal management system may instead be configured in or as any other suitable manner.

The heat exchanger assembly and thermal management system may be attached to an inside surface of a skin of a structure of a vehicle.

The exemplary method <NUM> includes at (<NUM>) positioning a heat exchanger assembly adjacent to, and thermal communication with, the inside surface of the skin the vehicle at a location between a first structural member and a second structural member of the structure.

The exemplary method <NUM> further includes at (<NUM>) providing a flow of gas to an inflatable bladder operable with the cooling tube of the heat exchanger assembly to press the cooling tube towards the inside surface of the skin.

Referring now to <FIG>, a method <NUM> of operating a heat exchanger assembly of a thermal management system operable with an inside surface of the skin of the vehicle is provided. The heat exchanger assembly and thermal management system may be configured in any suitable manner. For example, in certain exemplary embodiments, the heat exchanger assembly in thermal management system may be configured in accordance with one or more the exemplary embodiments described above with reference to <FIG>. However, in other embodiments, the heat exchanger assembly and thermal management system may instead be configured in or as any other suitable manner.

The heat exchanger assembly and thermal management system may be attached to an inside surface of a skin of a structure of a vehicle. In particular, the heat exchanger assembly may be positioned adjacent to, and thermal communication with, the inside surface of the skin the vehicle.

The exemplary method <NUM> includes at (<NUM>) providing a flow of gas to an inflatable member operable with a cooling unit of the heat exchanger assembly to press cooling unit towards the inside surface of the skin. Additionally, the method <NUM> includes at (<NUM>) determining a condition of the vehicle, of the thermal management system, or both; and at (<NUM>) modifying a pressure within the inflatable member in response to the determined condition of the vehicle, of the thermal management system, or both.

For the exemplary aspect depicted, the condition determined at (<NUM>) may be an operating condition of the vehicle, of the thermal management system, or both. For example, the condition may be indicative of a flight stage of the aircraft (e.g., takeoff, climb, cruise, descent, taxi, etc.), whether or not one or more of the engines are operating and at what power level they are operating, whether or not the thermal management system is operating, a speed at which the aircraft is operating (e.g., subsonic, supersonic, hypersonic), etc..

Also for the exemplary aspect depicted, modifying the pressure within the inflatable member at (<NUM>) may include at (<NUM>) at least partially deflating the inflatable member or at (<NUM>) at least partially inflating the inflatable member. In such a manner, the method <NUM> may control a pressure the inflatable member applies to the heating unit of the heat exchanger assembly based at least in part on the one or more conditions of the vehicle, the thermal management system, or both in order to provide a desired amount of heat transfer when desired, without damaging the skin of the vehicle.

Claim 1:
A vehicle, the vehicle comprising:
an engine (<NUM>, <NUM>) having a heat source;
a structure having a skin defining an inside surface, and
a thermal management system (<NUM>), the thermal management system comprising:
a heat exchanger assembly (<NUM>, 102A) comprising a structural backing (<NUM>) and a cooling unit, the structural backing (<NUM>) mounting the cooling unit in a position adjacent to, and in thermal communication with, the inside surface of the skin, the cooling unit formed of a flexible or semi-rigid material to conform to a shape of the inside surface of the skin;
wherein the thermal management system of the vehicle is thermally coupled to the heat source of the engine for rejecting heat from the heat source using the heat exchanger assembly, wherein the cooling unit is a cooling tube (<NUM>), and characterised in that the heat exchanger assembly (<NUM>) further includes an inflatable member (<NUM>) operable with the cooling tube (<NUM>) to press the cooling tube (<NUM>) towards the inside surface of the skin.