Patent Description:
High altitude long endurance (HALE) unmanned aircraft have been devised. These typically have long wingspans and low drag to improve their ability to operate efficiently for weeks or months at altitudes in excess of <NUM>. In some examples, HALE aircraft include one or more payloads comprising electronic components, such as sensors.

Operating at relatively low speeds and at high altitudes, airflow over the aircraft's surfaces is low. Therefore, it is difficult to effectively remove heat generated by electronic components. In some examples, the components have different operating temperature ranges and so it can be difficult to ensure that each of the components are working within their operating temperature range. <CIT>, <CIT> disclose HALE with a thermal management.

It would not be appropriate to fit an air conditioning unit or an arrangement of pumps and/or fans to a vehicle with stringent weight requirements, such as a HALE aircraft or a racing car.

Therefore, there is a need for a lightweight means for managing heat for one or more components.

According to one aspect, there is provided a high altitude long endurance aircraft comprising one or more first heat generating components and one or more second components, the one or more first heat-generating components and second components requiring thermal management and a thermal management apparatus. The apparatus comprises a chassis, in the form of a hollow tube, in thermal contact with one or more first heat-generating components and one or more second components, the first heat-generating components and second components being thermally coupled with the chassis, a flow control unit for defining a fluid flow path through the chassis, one or more first temperature sensors arranged to measure the temperature of the one or more first heat-generating components, one or more second temperature sensors arranged to measure the temperature of the one or more second components and a processor configured to compare the measured temperature of the one of more first heat-generating components with a first threshold temperature and the measured temperature of the one of more second components with a second threshold temperature and, if the measured temperature of the one or more first heat-generating components is higher than the first threshold temperature and, if the measured temperature of the one or more second components is less than the second threshold temperature, operate the flow control unit to permit a fluid to flow through the chassis to transfer heat from the one or more first components to the one or more second components.

A thermal management apparatus that comprises a chassis to transfer heat from one or more first components to the one or more second components provides a lightweight means to regulate the heat of components. For example, excess heat generated by the one or more first components can be used to heat one or more second components, as required. Further, as the chassis is providing the thermal management, the overall weight of a vehicle including this apparatus is reduced as there is no requirement for a separate heat regulation system.

In one example, the fluid is air that can be used to aid with the transfer of heat from the one or more first components to the one or more second components.

The thermal management apparatus may include one or more heaters configured to add heat to the chassis. The one or more heaters may be used to provide additional heat to the chassis and the one or more first components and the one or more second components.

In one example, the thermal management apparatus comprises a coating configured to radiate excess heat from the chassis. The coating is used when there is too much heat in the chassis, the one or more first components and the one or more second components.

The thermal management apparatus may include the one or more first components; and the one or more second components, wherein the one of more first components have a first power output; and the one or more second component have a second set power output, wherein the first power output is higher than the second power output.

In some examples, the flow control unit comprises one or more controllable valves that may be configured to adjust the amount or direction of fluid that may flow through the chassis.

In one example, the thermal management apparatus comprises a heat pipe in addition to the chassis.

The heat pipe may include an evaporator end and a condenser end; a vapour arranged to flow from the evaporator end to the condenser end; and a working fluid arranged to flow from the condenser end to the evaporator end, wherein the heat pipe is arranged such that the evaporator end is arranged in proximity to the one or more first components to absorb heat from the one or more first components; and wherein the condenser end is arranged in proximity to the one or more second components to transfer heat to the one or more second components. The provision of a heat pipe in addition to the chassis provides an additional means for transferring heat from the one or more first components to the one or more second components.

In one example, the thermal management apparatus comprises: translation means for causing the heat pipe to translate from a first configuration to a second configuration in response to a control signal, wherein in the first configuration the evaporator end is arranged in proximity to the one or more first components and in the second configuration the evaporator end is arranged at a greater distance from the one or more first components than in the first configuration.

In one example, the heat pipe is telescopic and wherein the translation means comprises means for selectively extending or contracting the heat pipe such that the evaporator end respectively moves toward or away from the one or more first components.

The thermal management apparatus may comprise a switch for modifying the flow of vapour along the heat pipe in response to a control signal to increase or decrease the rate of heat loss from the one or more first components.

High Altitude Long Endurance aircraft are subject to very tight weight restrictions and so repurposing heat from the one or more first components to heat the one or more second components removes the requirement for additional air conditioning or heating systems.

According to one aspect, there is provided a method of thermal management in a high altitude long endurance aircraft, comprising: measuring the temperature of one or more first heat-generating components; measuring the temperature of one or more second components; comparing the measured temperature of the one or more first heat-generating components with a first threshold temperature; comparing the measured temperature of the one or more second components with a second threshold temperature; if the measured temperature of the one or more first heat-generating components s less than the first threshold temperature and if the measured temperature of the one or more second components is less than the second threshold temperature, generating a control signal for controlling the flow control unit to modify the flow path of the chassis in response to permit a fluid to flow through the chassis to transfer heat from the one or more first heat-generating components to the one or more second components.

The method may include the steps of generating a control signal for controlling a switch in dependence on the measured temperature; and controlling the switch to modify a flow path of vapour along the heat pipe in response to the control signal to increase or decrease the rate of heat transfer from the one or more first components to the one or more second components.

It will be appreciated that features described in relation to one aspect of the present invention can be incorporated into other aspects of the present invention. For example, an apparatus of the invention can incorporate any of the features described in this disclosure with reference to a method, and vice versa. Moreover, additional embodiments and aspects will be apparent from the following description, drawings, and claims. As can be appreciated from the foregoing and following description, each and every feature described herein, and each and every combination of two or more of such features, and each and every combination of one or more values defining a range, are included within the present disclosure provided that the features included in such a combination are not mutually inconsistent. In addition, any feature or combination of features or any value(s) defining a range may be specifically excluded from any embodiment of the present disclosure.

Embodiments of the invention will now be described by way of example only and with reference to the accompanying drawings.

For convenience and economy, the same reference numerals are used in different figures to label identical or similar elements.

Embodiments herein generally relate to a thermal management apparatus for use with a vehicle. The thermal management apparatus includes a chassis with more components thermally coupled with the chassis. There is one or more first components and one or more second components.

The chassis is arranged to regulate heat for the one or more first components and the one or more second components. The chassis is arranged to remove heat from the one or more first components and transfer the heat to one or more second components. As such, the chassis is able to effectively repurpose heat, that otherwise would have been lost from the apparatus and use it to heat the one or more second components.

The chassis is configured to draw heat away from the one or more first components, which may be sources of heat within the vehicle, such as sensors, imaging systems and moving parts that generate heat through friction.

Prior art thermal management systems for vehicles include, for example, radiators for cooling engines on cars or coolant systems powered by an auxiliary power unit for avionics bays in aircraft. These tend to be relatively heavy and complex systems and so are undesirable to include vehicles that have weight restrictions.

<FIG> shows an illustrative example of an aircraft <NUM>, specifically a HALE unmanned aeroplane. While an aircraft <NUM> is shown here, it would be readily appreciated that the present invention is applicable to other types of vehicles, such as cars, ships, spacecraft, airships and trains. The present invention is particularly applicable to vehicles operate in environments where there is limited air flow. Further this invention is also particular applicable to vehicles that have burdensome weight restrictions, as the thermal management apparatus described herein tends to be relatively light weight and may use existing components for thermal management. The aircraft <NUM> includes a wing member <NUM>. In one example, the wing span of the wing member <NUM> is approximately <NUM> metres and has a relatively narrow chord (i.e. of the order <NUM> metre). The wing member <NUM> is coupled to a fuselage <NUM>. To aerodynamically balance the aircraft <NUM>, a horizontal tail plane <NUM> and a vertical tail fin (or vertical stabilizer) <NUM> are coupled to the rear of the fuselage <NUM>. A payload module <NUM> may be coupled to the front of the fuselage <NUM>, i.e. the nose of the aircraft <NUM>. In one example, the payload module <NUM> is detachable from the fuselage <NUM>. The payload module <NUM> may be a pod that includes one or more first components and one or more second components that require thermal management, which is described in more detail below.

An engine having a propeller is mounted to the wing member <NUM> on both sides of the fuselage <NUM>. The engines are powered by a combination of solar panels mounted to the upper surfaces of the wing member <NUM> and batteries disposed inside the fuselage <NUM> and/or wing member <NUM>.

The aircraft <NUM> is of lightweight construction. For example, the fuselage <NUM>, wing member <NUM>, payload module <NUM>, tailplane <NUM> and tail fin <NUM> may be made of a monocoque carbon fibre laminate skin structure. In other words, the skin forms the aircraft's body. In other embodiments, the body is substantially made of a light weight metal, such as titanium, titanium alloy, aluminium or aluminium alloy.

<FIG> shows a schematic diagram of a thermal management apparatus <NUM> for use with a vehicle, such as the aircraft <NUM>. <FIG> shows an example of a thermal management apparatus <NUM> comprising a chassis <NUM> that is thermally coupled with one or more first components <NUM> and one or more second components <NUM>.

In one example, the thermal management apparatus <NUM> is part of the payload module <NUM> of a vehicle, such as an aircraft <NUM>. In some examples, the payload module <NUM> is a pod coupled to a front of a vehicle and includes the thermal management apparatus <NUM>. In other examples, the payload module <NUM> is the thermal management apparatus <NUM>. In some examples, the payload module <NUM> includes one or more first components <NUM> and one or more second components <NUM>. In some examples, the one or more first components <NUM> and one or more second components <NUM> are part of the thermal management apparatus <NUM> itself.

Whilst both the one or more first components <NUM> and the one or more second components <NUM> may generate heat, in some examples, the one or more second components <NUM> may require additional heat in order to work effectively. For example, the aircraft <NUM> may be deployed at a high altitude so the temperature and pressure of the surrounding air may be very low. As such, one or more second components <NUM>, such as camera equipment, may require additional heat to operate effectively and/or to prevent a reduction in their performance. The one or more first components <NUM> may have a higher power output compared with the one or more second components <NUM> and so the one or more first components <NUM> may generate more heat compared with the one or more second components <NUM>.

As mentioned above, the thermal management apparatus <NUM> is thermally coupled with one or more first components <NUM> that generate heat when in operation. For example, a processor, batteries or radio equipment may all generate heat whilst in use. Due to the relatively low airspeed of air crossing the surfaces of the aircraft <NUM>, and the low air density at the high altitudes at which it tends to operate, it can be difficult to draw heat away from the aircraft <NUM>. It is important to draw heat away from heat sources, such as the one or more first components <NUM>, at least in some circumstances, to prevent damage to components of the aircraft <NUM> or to prevent a reduction in their performance.

The chassis <NUM> of the thermal management apparatus <NUM> is thermally coupled with both the one or more first components <NUM> and the one or more second components <NUM> and is configured to draw heat away from the one or more first components <NUM> and transfer at least some of the heat drawn from the one or more first components <NUM> to the one or more second components <NUM>. Heat may be drawn away from the one or more first components <NUM> via conduction, convection or radiation and transferred to the one or more second components via conduction, convection or radiation. In some examples, the chassis <NUM> of the thermal management apparatus <NUM> is configured to substantially equalise the temperature of the one or more first components <NUM> and the one or more second components <NUM>. Further, the chassis <NUM> is configured to provide heat to the one or more second components <NUM> that require heating.

The thermal management apparatus <NUM> includes temperature sensors <NUM>. The temperature sensors <NUM> are configured to determine the temperature of the one or more first components <NUM> and the temperature of the one or more second components <NUM>. In one example, the one or more temperature sensors <NUM> may comprise a first set of temperature sensors to measure the temperature of the one or more first components <NUM> and a second set of temperature sensors to measure the temperature of the one or more second components <NUM>, even if they have different power outputs.

In one example, the thermal management apparatus <NUM> includes one or more heaters <NUM> in order to provide a supplemental heating to the one or more first components <NUM> and/or the one or more second components <NUM> if the heat generated by the one or more first components <NUM> is not sufficient to effectively heat the one or more second components <NUM> to their required operating temperature. However, in other examples, the thermal management apparatus <NUM> does not include any additional heaters <NUM> or cooling elements further to the chassis <NUM>. One or more of the first components <NUM> or second components <NUM> may be heat radiating devices, which thereby act as heat sinks.

In one example, the one or more first components <NUM> are physically coupled to the chassis <NUM> of the thermal management apparatus <NUM>. The chassis <NUM> is, in effect a supporting frame for the one or more first components <NUM>. The one or more second components <NUM> may also be physically coupled to chassis <NUM> of the thermal management apparatus <NUM>. For example, the one or more first components <NUM> may be releasably attached to the chassis <NUM> of the thermal management apparatus <NUM> and the one or more second components <NUM> may also be releasably attached to chassis <NUM> of the thermal management apparatus <NUM>. In other examples, the one or more first components <NUM> are fixed to the chassis <NUM> of the thermal management apparatus <NUM> and the one or more second components <NUM> are fixed to chassis <NUM> of the thermal management apparatus <NUM>.

In one example, the chassis <NUM> of the thermal management apparatus <NUM> is substantially hollow such that a fluid, such as air, may flow through a flow path in the chassis <NUM> of the thermal management apparatus <NUM>. In this example, the one or more first components <NUM> may be located "upstream" of the one or more second components <NUM>. In this example, heat may be drawn from the one or more first components <NUM> via convection or radiation to the fluid. Then as the fluid passes the one or more second components <NUM>, heat may be transferred from the fluid to the one or more second components <NUM>. The chassis <NUM> is formed of a hollow tube. In this example, the one or more first components <NUM> and the one or more second components <NUM> may be coupled or attached to an outside surface of the hollow tube chassis <NUM>.

In one example, the thermal management apparatus <NUM> comprises a coating configured to radiate excess heat from the chassis <NUM>. In one example, an outside surface of the chassis <NUM> includes a coating configured to substantially reflect light. The chassis <NUM> may be coated in a black paint.

The provision of the coating allows maximum heat dissipation in the target environment by radiating any excess heat generated by the one or more first components <NUM> that is not required by the one or more second components <NUM>. In other words, if the one or more first components <NUM> are at a temperature higher than a first threshold (e.g., the operating temperature of the one or more first components <NUM>) and the one or more second components <NUM> are at a temperature higher than a second threshold (e.g., the operating temperature of the one or more second components <NUM>), then the chassis <NUM> may act as a heat sink for the one or more first components <NUM> and the one or more second components <NUM>.

In one example, the thermal management apparatus <NUM> also includes a heat pipe <NUM> in addition to the chassis <NUM> for drawing heat away from the one or more first components <NUM> and transferring the heat to the one or more second components <NUM>. An example of a heat pipe <NUM> is shown in more detail in <FIG>. The heat pipe <NUM> may provide an additional means for transferring heat from the one or more first components <NUM> to the one or more second components <NUM>.

In this example, the heat pipe <NUM> is a passive elongate sealed heat-transfer device that combines the principles of both thermal conductivity and phase transition to effectively transfer heat between two solid interfaces. The heat pipe <NUM> would be familiar to someone skilled in the art of manufacturing microelectronics and relatively small electronic consumer devices, for example, but not generally to someone designing a vehicle, particularly an aircraft <NUM>.

The heat pipe <NUM> comprises a vacuum-tightened vessel <NUM>, porous wick structure <NUM>, and working fluid <NUM>. The wick structure <NUM> is arranged on the inside of the vessel <NUM> at the end of the heat pipe <NUM> proximate to the one or more first components <NUM>. This end of the heat pipe <NUM> functions as an evaporator. As heat from the one or more first components <NUM> is input at the evaporator end, the fluid <NUM> vaporises, creating a pressure gradient. This pressure gradient pushes the vapour to flow along the heat pipe <NUM>, through the central channel, to the condenser end (i.e. the end proximate the one or more second components <NUM>) where it condenses due to this end being cooler, giving up its latent heat of vaporisation. The working fluid <NUM> is then returned to the evaporator end by capillary forces developed in the wick structure <NUM> or by gravity.

The vessel <NUM> (i.e. main body) of the heat pipe <NUM> comprises a material having high strength and high thermal conductivity, such as copper or aluminium. The working fluid <NUM> comprises a fluid having high latent heat and high thermal conductivity, such as liquid helium, ammonia, alcohol or ethanol. In a preferred embodiment, liquid helium is used as the working fluid <NUM> as it is efficient at the ambient temperatures in which a HALE aircraft will typically operate, for example down to -<NUM> degrees Celsius. The wick structure <NUM> maintains effective capillary action when bent or used against gravity. The wick structure <NUM> comprises, for example, sintered copper powder, screen or a series of grooves parallel to the longitudinal axis of the heat pipe <NUM>.

The evaporator end of the heat pipe <NUM> is disposed in proximity to the one or more first components <NUM>. The opposite end (i.e. the condenser end) of the heat pipe <NUM> is disposed in proximity to the one or more second components <NUM>. In some examples, the condenser end of the heat pipe <NUM> is bifurcated such that one branch of the condenser end is disposed adjacent a first set of one or more second components <NUM> and another branch of the condenser end is disposed adjacent a second set of one or more second components <NUM>. In the embodiment shown in <FIG>, the heat pipe <NUM> is not bifurcated. In the example shown in <FIG>, there is one first component <NUM> from which heat is removed and then delivered to two second components <NUM>.

The heat pipe <NUM> may be used in addition to the chassis <NUM> to provide an additional means of transferring heat from the one or more first components <NUM> to the one or more second components <NUM>. However, the heat pipe <NUM> comes with a weight disadvantage, and so in one example, the thermal management apparatus <NUM> includes a chassis <NUM> without an additional heat pipe <NUM>.

Further, the evaporator end of the heat pipe <NUM> may be bifurcated, or further divided, to approach the one or more first components <NUM> from different directions or to allow a single heat pipe <NUM> to be used to transport heat away from a plurality of first components <NUM>.

<FIG> shows a plan view of a thermal management apparatus <NUM> implemented in an aircraft <NUM>.

In this example, the thermal management apparatus <NUM> comprises a pod that is configured to couple with the vehicle. In the example shown in <FIG>, the thermal management apparatus <NUM> is coupled to the front of the vehicle, but in other examples, the thermal management apparatus <NUM> is coupled to another part of the vehicle. In some examples, the thermal apparatus <NUM> is a part of the vehicle itself, for example, as described above, the thermal apparatus <NUM> may be the payload <NUM>. In some example, the thermal management apparatus <NUM> may be coupled to a balloon.

In the example shown in <FIG>, the chassis <NUM> acts as the physical interface between the one or more first components <NUM>, the one or more second components <NUM> and the aircraft <NUM>. This makes efficient use of the space, weight and power constraints associated with the operating environment.

The thermal management apparatus <NUM> includes a flow control unit <NUM> and a controller <NUM>. The controller <NUM> may be part of the flow control unit <NUM>, or a separate but electrically connected component.

The flow control unit <NUM> may include at least one controllable valve for directing fluid around or through the chassis <NUM>. The one or more controllable valves may be adjusted to restrict the amount of fluid that passes through the chassis <NUM>. In other words, the flow control unit <NUM> is configured to set or define a flow path in the chassis <NUM>. In the example of the chassis <NUM> comprising a hollow member, such as hollow tube, then the flow control unit <NUM> may be configured to control the flow of fluid, such as air, through the hollow of the chassis <NUM>. The flow control unit <NUM> may include one or more pivotable flaps that may adjust the flow path of fluid in the chassis. In other words, the flow control unit <NUM> has one or more movable parts to adjust the flow path through the chassis <NUM>.

In the example in which the thermal management apparatus <NUM> also comprises the heat pipe <NUM>, the controller <NUM> may be configured to control a switch <NUM> to control the flow of the heat transport medium (i.e. vapour and working fluid <NUM>) to continue to flow along the heat pipe <NUM> from the one or more first components <NUM> toward or away from the one or more second components <NUM>. The switch <NUM> may comprise a valve disposed in the heat pipe <NUM>.

The valve in the heat pipe <NUM> may control the amount of heat transport medium that travels through the heat pipe <NUM>. As such, the rate at which heat is drawn from the one or more first components <NUM> (i.e. the rate at which the one or more first components <NUM> is cooled) may be controlled.

The one or more temperature sensors <NUM> may be, for example, a thermocouple. The temperature sensor <NUM> may be incorporated onto a MEMS chip. In some embodiments one or more temperature sensors <NUM> may be integrated with the one or more first components <NUM> and/or the one or more second components <NUM>. In other embodiments, the temperature sensor <NUM> is disposed adjacent to the one or more first components <NUM> and/or the one or more second components <NUM>. The one or more temperature sensors <NUM> may be electrically coupled to the controller <NUM>. The one or more temperature sensors <NUM> may transmit a continuous signal to the controller <NUM> indicative of the temperature of the one or more first components <NUM> and/or the one or more second components <NUM>. In embodiments where there is a plurality of first components <NUM>, there may be a plurality of temperature sensors <NUM>, each associated with each first component <NUM>. In embodiments where there is a plurality of second components <NUM>, there may be a plurality of temperature sensors <NUM>, each associated with each second component <NUM>.

The controller <NUM> may take any suitable form. For instance, it may be a microcontroller, plural microcontrollers, a processor, or plural processors. The controller <NUM> may receive the signal indicative of temperature of the one or more first components <NUM> from the temperature sensor <NUM>. The controller <NUM> may receive the signal indicative of temperature of the one or more second components <NUM> from the temperature sensor <NUM>. The controller <NUM> may include a memory to store the measurements of the temperature sensor <NUM>.

The controller <NUM> compares the temperature of the one or more first components <NUM> with a first threshold temperature. The first temperature threshold may be indicative of an operating temperature (or a range of operating temperatures) in which the one or more first components <NUM> is configured to operate effectively.

The controller <NUM> compares the temperature of the one or more second components <NUM> with a second threshold temperature. The second temperature threshold may be indicative of an operating temperature (or a range of operating temperatures) in which the one or more second components <NUM> is configured to operate effectively.

The controller <NUM> processes the received temperatures and generates a control signal to control the flow control unit <NUM> to change the flow rate of fluid through the chassis <NUM>. In other examples, the controller <NUM> may generate a control signal for the switch <NUM> to control the flow of the heat transfer medium in the heat pipe <NUM> in dependence on the received temperatures.

If the temperature of the one or more first components <NUM> is higher than the first threshold, then the controller <NUM> determines that the one or more first components <NUM> has generated excess heat.

Further, if the temperature of the one or more second components <NUM> is lower than the second threshold, then the controller determines that that the one or more second components <NUM> requires additional heat.

The controller <NUM> generates a control signal for the flow control unit <NUM> to modify the flow path of fluid in the chassis <NUM> such that heat loss from the one or more first components <NUM> is promoted and heat is transferred from the one or more first components <NUM> to the one or more second components <NUM>.

This may be advantageous where a system on-board the aircraft <NUM> has several components that operate at different powers and temperatures. For example, Commercial Off the Shelf (COTS) derived equipment (e.g. optics, router or radios) may not be able to operate correctly or effectively at the altitudes (i.e. low temperatures) HALE aircraft typically operate at. It may further be desirable it limit the rate of heat loss from the vehicle as some excess heat is re-purposed and used to heat one or more second components <NUM> that require heating.

Where the temperature of the one or more second components <NUM> exceeds the second threshold (i.e. reaches its operating temperature), then the controller <NUM> may generate a control signal for the flow control unit <NUM> to modify the flow path of fluid in the chassis <NUM> such that less heat is transferred from the one or more first components <NUM> to one or more second components <NUM> so that the one or more second components are not heated too much.

In some embodiments, the switch <NUM> is a mechanism for physically moving the evaporator end of the heat pipe <NUM> away from the one or more first components <NUM> such that less heat is drawn away from the one or more first components <NUM>. In one embodiment, the heat pipe <NUM> is telescopic. Here, the switch <NUM> comprises a motor for driving the heat pipe <NUM> to extend or contract in response to a control signal from the controller <NUM>. In other words, the controller <NUM> receives a temperature measurement from the one or more temperature sensors <NUM>. If the measured temperature of the one or more first components <NUM> is less than a threshold, indicating that the one or more first components <NUM> is too cold, the controller <NUM> generates a control signal for the switch <NUM> to retract (or contract) the heat pipe <NUM> to move the evaporator end away from the one or more first components <NUM>.

If the controller <NUM> subsequently receives a temperature measurement from the one or more temperature sensors <NUM> indicating that the measured temperature of the one or more first components <NUM> is higher than a threshold, then the controller <NUM> generates a control signal for the switch <NUM> to extend the heat pipe <NUM> to move the evaporator end towards the one or more first components <NUM>.

In an alternative embodiment again, the switch <NUM> comprises a pivot point or rotary hinge. It may comprise a rack and pinion or other gear arrangement for rotating the heat pipe <NUM> about the pivot point to move the evaporator end of the heat pipe <NUM> away from into proximity with the one or more first components <NUM>. In an alternative embodiment again, the switch <NUM> comprises a sliding mechanism for relocating/repositioning the heat pipe <NUM>.

<FIG> shows an example of a method of managing the temperature in a heat transfer apparatus.

As step <NUM>, the temperature of one or more first components <NUM> is measured.

At step <NUM>, the temperature of one or more second components <NUM> is measured.

At step <NUM>, heat is transferred from the one or more first components <NUM> to the one or more second components <NUM> based on the temperature of the one or more first components <NUM> and the temperature of the one or more second components <NUM>.

Embodiments herein have described the thermal management apparatus with reference to an aircraft <NUM>. However, it would be appreciated that other types of vehicular implementations are anticipated. For example, the lightweight construction of the thermal management apparatus is readily applicable to sports cars, for example Formula <NUM>™ cars, or lighter-than-air vehicles, such as balloons.

A method of manufacturing a thermal management apparatus <NUM> is described below. A chassis <NUM> is provided. The chassis <NUM> may be formed from injection moulding, such as metal injection moulding. The chassis <NUM> is substantially hollow such that a fluid, such as air, may flow through a flow path in the chassis <NUM> of the thermal management apparatus <NUM>. The chassis <NUM> may be extruded to the desired shape.

The method of manufacturing includes thermally coupling one or more first components <NUM> that require thermal management with a first position of the chassis <NUM>. For example, one or more first components <NUM> that require heat to be removed from them are selected and thermally coupled with the chassis <NUM> at a first position, for example in an "upstream" position.

The method of manufacturing includes thermally coupling one or more second components <NUM> that require thermal management with a second position of the chassis <NUM>. For example, one or more second components <NUM> that require heat to be added to them are selected and thermally coupled with the chassis <NUM> at a second position, for example in an "downstream" position relative to the one or more first components <NUM>.

In this example, heat may be drawn from the one or more first components <NUM> via convection or radiation to the fluid. Then as the fluid passes the one or more second components <NUM>, heat may be transferred from the fluid to the one or more second components <NUM>. In one example, the chassis <NUM> is formed of a hollow tube. In this example, the one or more first components <NUM> and the one or more second components <NUM> may be coupled or attached to an outside surface of the hollow tube chassis <NUM> and fluid may pass through the hollow tube. As such, the chassis <NUM> is configured to transfer heat from the one or more first components <NUM> to the one or more second components <NUM>.

The method of manufacturing a thermal management apparatus may include the steps of providing one or more first temperature sensors <NUM> to measure the temperature of the one or more first components <NUM> and providing one or more second temperature sensors <NUM> to measure the temperature of the one or more second components <NUM>.

The method of manufacturing may include the steps of providing a flow control unit <NUM> for modifying the flow path for the chassis <NUM>. For example, the flow control unit <NUM> may have movable parts that may modify flow through the chassis <NUM>.

Claim 1:
A high altitude long endurance aircraft (<NUM>) comprising:
one or more first heat-generating components (<NUM>) and one or more second components (<NUM>), the one or more first heat-generating components (<NUM>) and second components (<NUM>) requiring thermal management;
a thermal management apparatus (<NUM>) comprising:
a chassis (<NUM>), in the form of a hollow tube, in thermal contact with the one or more first heat-generating components (<NUM>) and the one or more second components (<NUM>), the first heat-generating components (<NUM>) and second components (<NUM>) being thermally coupled with the chassis (<NUM>);
characterised in that it further comprises
a flow control unit (<NUM>) for modifying a fluid flow path through the chassis (<NUM>);
one or more first temperature sensors (<NUM>) arranged to measure the temperature of the one or more first heat-generating components (<NUM>);
one or more second temperature sensors (<NUM>) arranged to measure the temperature of the one or more second components (<NUM>); and
a controller (<NUM>) configured to compare the measured temperature of the one of more first heat-generating components (<NUM>) with a first threshold temperature and the measured temperature of the one of more second components (<NUM>) with a second threshold temperature and, if the measured temperature of the one or more first heat-generating components (<NUM>) is higher than the first threshold temperature and, if the measured temperature of the one or more second components (<NUM>) is less than the second threshold temperature, operate the flow control unit (<NUM>) to permit a fluid to flow through the chassis (<NUM>) to transfer heat from the one or more first heat-generating components (<NUM>) to the one or more second components (<NUM>).