Heat exchangers and aircraft

Abstract

A heat exchanger is provided that can simultaneously cool an object to be cooled and suppress unevenness (distortion) in the distribution of the total pressure of the airflow flowing into a propulsion device, while suppressing an increase in the number of parts in an aircraft. [Solution] This heat exchanger 4 is a heat exchanger installed in an aircraft 100 equipped with a second propulsion unit 3 having rotor blades 30, and comprises a base 40 and a plurality of heat dissipation fins 41 installed on the base 40, the base 40 being positioned forward of the rotor blades 30 in the direction of travel of the aircraft 100, and the plurality of heat dissipation fins 41 have at least one of their height H1, shape, angle θ1 relative to the base 40, and spacing P1 changed according to the total pressure distribution 80 of the airflow flowing into the second propulsion unit 3.

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger and an aircraft. [Background technology]

[0002] BACKGROUND ART Conventionally, an aircraft is known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses an aircraft equipped with an engine. The aircraft disclosed in Patent Document 1 is provided with vortex generating vanes. The vortex generating vanes are provided on the inner circumferential surface of the engine on the airflow inlet side to generate vortices that suppress pressure disturbances on the fan surface of the engine caused by the airflow flowing into the engine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent No. 7,784,732 Summary of the Invention [Problem to be solved by the invention]

[0005] Although not disclosed in Patent Document 1, an aircraft is provided with a heat exchanger for cooling an object to be cooled, such as lubricating oil used in an engine (propulsion device). Providing both vortex generating vanes that generate vortices to control the airflow flowing into the propulsion device, as disclosed in Patent Document 1, and a heat exchanger for cooling the object to be cooled, such as lubricating oil, increases the number of parts in the aircraft. Therefore, there is a need for a technology that can simultaneously cool the object to be cooled and suppress uneven distribution of the total pressure of the airflow flowing into the propulsion device (hereinafter referred to as distortion), while suppressing an increase in the number of parts in the aircraft.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a heat exchanger and an aircraft that can simultaneously cool an object to be cooled and suppress distortion of the airflow flowing into a propulsion device, while suppressing an increase in the number of parts in the aircraft. [Means for solving the problem]

[0007] In order to achieve the above object, a heat exchanger according to a first aspect of the present invention is a heat exchanger provided in an aircraft having a propulsion device with rotor blades, the heat exchanger comprising: a base; and a plurality of heat dissipation fins provided on the base, the base being disposed forward of the rotor blades in a direction of travel of the aircraft, and the plurality of heat dissipation fins: When multiple heat dissipation fins are not installed of the airflow entering the propulsion system The total pressure distribution on the front of the rotor blade is such that the aerodynamic loss increases as the total pressure increases. At least one of the height, shape, angle relative to the base, and spacing at which they are arranged is changed.

[0008] As described above, a heat exchanger according to a first aspect of the present invention comprises: When multiple heat dissipation fins are not installed of the airflow into the propulsion system The total pressure distribution on the front of the rotor blade is such that the aerodynamic loss increases as the total pressure increases. The heat exchanger includes a plurality of heat dissipation fins that are modified in at least one of their height, shape, angle relative to the base, and spacing. This allows the plurality of heat dissipation fins of the heat exchanger to adjust the total pressure of the airflow flowing into the propulsion device. That is, the plurality of heat dissipation fins can both cool the object to be cooled and suppress distortion of the airflow flowing into the propulsion device. Therefore, compared to a configuration that includes, for example, a heat exchanger and a component separate from the heat exchanger that adjusts the total pressure of the airflow flowing into the propulsion device, an increase in the number of aircraft parts can be suppressed. As a result, it is possible to achieve both cooling of the object to be cooled and suppression of distortion of the airflow flowing into the propulsion device while suppressing an increase in the number of aircraft parts. Here, if distortion occurs in the airflow flowing into the propulsion device, it can reduce the efficiency of the rotor blades provided in the propulsion device, increase the noise of the rotor blades due to the distortion, and increase the risk of fatigue failure of the rotor blades due to increased cyclic loads on the rotor blades. This can result in increased energy consumption of the aircraft, increased environmental impact of the aircraft, and reduced reliability of the aircraft. Therefore, with the above-described configuration, the multiple heat dissipation fins can increase aerodynamic loss at locations where total pressure is high, thereby homogenizing the distribution of total pressure. This reduces airflow distortion in front of the rotor blades of the propulsion device. Therefore, it is possible to suppress a decrease in efficiency of the rotor blades of the propulsion device. Therefore, it is possible to improve the efficiency of the rotor blades of the propulsion device. As a result, it is possible to suppress an increase in energy consumption of the aircraft. Furthermore, since the distortion of the airflow in front of the rotor blades of the propulsion device is reduced, it is possible to reduce rotor blade noise due to distortion generated in the propulsion device. As a result, it is possible to reduce the environmental impact of the aircraft. Furthermore, it is possible to homogenize the distribution of total pressure, thereby suppressing an increase in cyclic loads on the rotor blades. As a result, the risk of fatigue failure in the rotor blades of the propulsion device can be reduced, thereby improving the reliability of the aircraft.

[0010] In this case, preferably, the plurality of heat dissipation fins are modified in at least one of their height, shape, angle relative to the first base, and spacing so that aerodynamic loss increases at locations where the total pressure is higher in the distribution of the total pressure of the airflow drawn into the propulsion device, including the flow interfering with the aircraft airframe. Here, the airflow, including the flow interfering with the aircraft airflow, is more turbulent than the airflow passing under the aircraft's wings. Therefore, the airflow drawn into the propulsion device, including the flow interfering with the aircraft airflow, has a distorted airflow distribution. Therefore, with the above configuration, at least one of their height, shape, angle relative to the first base, and spacing is modified so that aerodynamic loss increases at locations where the total pressure is higher. Therefore, by adjusting the area of ​​each heat dissipation fin and the speed of the airflow acting on the heat dissipation fin at locations where the total pressure is higher, aerodynamic loss can be effectively controlled. Therefore, distortion of the airflow drawn into the propulsion device, including the flow interfering with the aircraft airframe, can be effectively reduced. Therefore, it is possible to effectively suppress a decrease in the efficiency of the rotor blades of the propulsion device, an increase in the noise of the rotor blades due to distortion, and an increase in the cyclic load on the rotor blades, and as a result, it is possible to provide a heat exchanger that can effectively suppress an increase in the energy consumption of the aircraft, effectively reduce the environmental load of the aircraft, and effectively improve the reliability of the aircraft.

[0011] In the above-described configuration, the plurality of fins include a flow interfering with the aircraft fuselage, and at least one of their height, shape, angle relative to the first base, and spacing is varied so that aerodynamic loss increases at locations where the total pressure of the airflow drawn into the propulsion device is higher. Preferably, the plurality of fins are configured so that their height increases at locations where the total pressure is higher. With this configuration, increasing the height of the fins allows the area of ​​each fin, as viewed from the direction of flight of the aircraft, and the speed of the airflow acting on each fin to be varied according to the height of the fins. This allows aerodynamic phenomena to be adjusted, thereby controlling aerodynamic loss at locations where the total pressure is high. This facilitates reducing distortion of the airflow flowing into the propulsion device. Furthermore, increasing the height of the fins increases the heat transfer area between the fins and the airflow, thereby improving heat exchange capacity. As a result, it is possible to provide a heat exchanger that reduces distortion of the airflow flowing into the propulsion device while ensuring the amount of heat dissipation in the heat exchanger.

[0012] In the heat exchanger according to the first aspect, the base preferably has a flow path formed therein through which a fluid to be heat exchanged can flow, and the plurality of heat dissipation fins are used for both heat exchange between the fluid flowing through the flow path and air flowing between the plurality of heat dissipation fins and for rectifying the airflow flowing into the propulsion device. With this configuration, since the base has a flow path through which a fluid can flow, heat exchange can be performed between a fluid such as lubricating oil and the airflow. As a result, compared to a configuration including a heat exchanger and a separate component for adjusting the total pressure of the airflow flowing into the propulsion device, it is possible to cool a fluid such as lubricating oil while minimizing an increase in the number of aircraft parts.

[0013] An aircraft according to a second aspect of the present invention comprises an airframe, a propulsion device mounted on the airframe and having rotor blades, a first heat exchanger having a first base and a plurality of first heat dissipation fins mounted on the first base, the first heat exchanger being mounted forward of the rotor blades in a direction of travel of the airframe, and the plurality of first heat dissipation fins When the plurality of first heat dissipation fins are not arranged of the airflow into the propulsion system The total pressure distribution on the front of the rotor blade is such that the aerodynamic loss increases as the total pressure increases. Any of the height, shape, angle relative to the first base, and spacing at which they are arranged is changed.

[0014] As described above, an aircraft according to a second aspect of the present invention includes a first heat exchanger having a plurality of first heat dissipation fins. When the plurality of first heat dissipation fins are not arranged of the airflow into the propulsion system The total pressure distribution on the front of the rotor blade is such that the aerodynamic loss increases as the total pressure increases. The heat exchanger according to the first aspect has a height, a shape, an angle relative to the first base, or an interval at which the heat exchanger is disposed, which is changed. This makes it possible to provide an aircraft that can simultaneously cool the object to be cooled and suppress distortion of the airflow flowing into the propulsion device, while suppressing an increase in the number of parts, as with the heat exchanger according to the first aspect. Furthermore, with this configuration, similar to the heat exchanger according to the first aspect, it is possible to suppress a decrease in the efficiency of the rotor blades of the propulsion device, an increase in the noise of the rotor blades, and an increase in the cyclic load on the rotor blades. This also makes it possible to provide an aircraft that can suppress an increase in energy consumption, reduce the environmental load, and improve reliability.

[0016] In this case, preferably, the plurality of first heat dissipation fins include a flow that interferes with the surface of the airframe, and at least one of their height, shape, angle relative to the first base, and spacing is changed so that aerodynamic loss increases at positions with higher total pressure in the distribution of the total pressure of the airflow drawn into the propulsion device. With this configuration, as with the heat exchanger according to the first aspect, it is possible to effectively suppress a decrease in the efficiency of the rotor blades of the propulsion device, an increase in rotor blade noise due to distortion, and an increase in cyclic load on the rotor blades, thereby making it possible to provide an aircraft that can effectively suppress an increase in energy consumption, effectively reduce environmental loads, and effectively improve reliability.

[0017] In a configuration in which the plurality of heat dissipation fins include a flow that interferes with the aircraft fuselage and at least one of the height, shape, angle relative to the first base, and spacing is changed so that aerodynamic loss increases at locations where the total pressure of the airflow drawn into the propulsion device is higher, preferably, the plurality of first heat dissipation fins are configured so that their height increases at locations where the total pressure is higher within the total pressure distribution. With this configuration, it is possible to provide an aircraft that, like the heat exchanger according to the first aspect, achieves both reduced distortion of the airflow flowing into the propulsion device and a sufficient amount of heat dissipation in the heat exchanger.

[0018] In the aircraft according to the second aspect, preferably, a flow path through which a fluid to be heat exchanged can flow is formed in the first base portion, and the plurality of first heat dissipation fins are configured to communicate with the fluid flowing in the flow path and the plurality of first heat dissipation fins. No. 1 The heat dissipation fins are used for both heat exchange with the air flowing between the fins and rectifying the airflow flowing into the propulsion device. With this configuration, it is possible to provide an aircraft that can cool fluids such as lubricating oil while suppressing an increase in the number of parts, as with the heat exchanger according to the first aspect.

[0019] The aircraft according to the second aspect preferably further includes a second heat exchanger mounted on the airframe and having a second base and a plurality of second heat dissipation fins mounted on the second base, the second heat exchanger being located forward of the propulsion unit in the direction of travel. With this configuration, the airflow, which has been rectified to some extent by the second heat exchanger mounted forward of the propulsion unit, is further rectified by the first heat exchanger, thereby more effectively reducing distortion of the airflow flowing into the propulsion unit. As a result, it is possible to more effectively suppress a decrease in the efficiency of the propulsion unit's rotor blades and an increase in rotor blade noise due to distortion, thereby more effectively suppressing an increase in the aircraft's energy consumption and an increase in the aircraft's environmental impact. Furthermore, it is possible to more effectively suppress an increase in cyclic loads on the rotor blades, thereby more effectively improving the reliability of the aircraft. [Effects of the Invention]

[0020] According to the present invention, as described above, it is possible to provide a heat exchanger and an aircraft that can achieve both cooling of an object to be cooled and suppression of distortion of the airflow flowing into a propulsion device, while suppressing an increase in the number of parts in the aircraft. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a schematic perspective view of an aircraft equipped with a heat exchanger according to an embodiment of the present invention; [Figure 2] FIG. 2 is a block diagram for explaining functional blocks of an aircraft according to an embodiment of the present invention. [Figure 3] 1 is a schematic perspective view for explaining the configuration of a heat exchanger according to an embodiment of the present invention. [Figure 4] FIG. 3 is a schematic diagram illustrating the positional relationship between a heat exchanger according to an embodiment of the present invention and rotor blades of a second propulsion device. [Figure 5] FIG. 3 is a schematic diagram for explaining the distribution of total pressure acting on the rotor blades of the second propulsion device according to one embodiment of the present invention. [Figure 6] 2 is a schematic perspective view illustrating a plurality of heat dissipation fins provided in the heat exchanger according to the embodiment of the present invention. FIG. [Figure 7] 5A and 5B are schematic diagrams illustrating different heights of a plurality of heat dissipation fins according to an embodiment of the present invention. [Figure 8] FIG. 10 is a schematic perspective view of an aircraft equipped with a second heat exchanger according to a first variant of the present invention. [Figure 9] FIG. 10 is a schematic perspective view for explaining the configuration of a second heat exchanger according to a first modified example of the present invention. [Figure 10] FIG. 10 is a schematic perspective view of an aircraft equipped with a heat exchanger according to a second variant of the present invention. [Figure 11] FIG. 10 is a schematic diagram illustrating differences in height of a plurality of heat dissipation fins according to a second modified example of the present invention. [Figure 12] FIG. 10 is a schematic perspective view of an aircraft equipped with a heat exchanger according to a third variant of the present invention. [Figure 13] FIG. 10 is a schematic diagram illustrating differences in height of a plurality of heat dissipation fins according to a third modified example of the present invention. [Figure 14] FIG. 10 is a schematic perspective view of an aircraft equipped with a heat exchanger according to a fourth modification of the present invention. [Figure 15] FIG. 10 is a schematic diagram illustrating differences in height of a plurality of heat dissipation fins according to a fourth modified example of the present invention. [Figure 16] FIG. 10 is a schematic perspective view of an aircraft equipped with a heat exchanger according to a fifth modification of the present invention. [Figure 17] FIG. 10 is a schematic diagram illustrating differences in height of a plurality of heat dissipation fins included in a heat exchanger according to a fifth modified example of the present invention. [Figure 18] FIG. 13 is a schematic diagram illustrating the configuration of a plurality of heat dissipation fins included in a heat exchanger according to a sixth modified example of the present invention. [Figure 19] FIG. 13 is a schematic diagram illustrating the configuration of a plurality of heat dissipation fins included in a heat exchanger according to a seventh modification of the present invention. [Figure 20] FIG. 13 is a schematic diagram illustrating the configuration of a plurality of heat dissipation fins included in a heat exchanger according to an eighth modification of the present invention. [Figure 21] FIG. 13 is a schematic diagram for explaining the configuration of a plurality of heat dissipation fins included in a heat exchanger according to a ninth modification of the present invention. [Figure 22] FIG. 23 is a schematic diagram for explaining the configuration of a plurality of heat dissipation fins of a heat exchanger according to a tenth modification of the present invention. [Figure 23] FIG. 23 is a schematic diagram for explaining the configuration of a plurality of heat dissipation fins of a heat exchanger according to an eleventh modification of the present invention. [Figure 24] FIG. 23 is a schematic diagram for explaining the angles at which a plurality of heat dissipation fins of a heat exchanger according to a twelfth modification of the present invention are provided. [Figure 25] FIG. 23 is a schematic diagram for explaining the lengths of a plurality of heat dissipation fins of a heat exchanger according to a thirteenth modification of the present invention. [Figure 26]FIG. 23 is a schematic diagram for explaining a heat exchanger according to a fourteenth modification of the present invention. [Figure 27] FIG. 23 is a schematic diagram illustrating the arrangement of a heat exchanger and an object to be cooled according to a fourteenth modification of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0023] The configuration of an aircraft 100 equipped with a heat exchanger 4 according to one embodiment will be described with reference to Figures 1 to 7. The heat exchanger 4 is an example of the "first heat exchanger" in the claims.

[0024] (Overall aircraft configuration) The aircraft 100 of this embodiment shown in Figure 1 includes an airframe 1, a first propulsion unit 2, a second propulsion unit 3, and a heat exchanger 4. In Figure 1, the vertical direction is defined as the Z direction. Within the Z direction, the upward direction is defined as the Z1 direction, and the downward direction is defined as the Z2 direction. Also in Figure 1, the forward and backward movement direction of the aircraft 100 is defined as the X direction. Within the X direction, the forward direction is defined as the X1 direction, and the direction opposite to the forward direction is defined as the X2 direction. Also, the direction perpendicular to both the Z direction and the X direction is defined as the Y direction. Within the Y direction, one side is defined as the Y1 direction, and the other side is defined as the Y2 direction.

[0025] The aircraft 1 includes a main wing 10 , a vertical tail 11 , and a horizontal tail 12 .

[0026] The first propulsion unit 2 is provided under the main wing 10. The first propulsion unit 2 is the main engine of the aircraft 100. The first propulsion unit 2 is configured to obtain thrust by discharging airflow that flows in from the X1 direction in the X2 direction. The first propulsion unit 2 is, for example, a jet engine.

[0027] The second propulsion unit 3 is mounted on the aircraft 1. Specifically, the second propulsion unit 3 is mounted on the X2 direction side of the vertical stabilizer 11. The second propulsion unit 3 has rotor blades 30. The second propulsion unit 3 is mounted on the rear (X2 direction side) of the aircraft 1 as an auxiliary propulsion unit for the first propulsion unit 2. The second propulsion unit 3 is configured to obtain propulsive force by taking in airflow flowing along the outer surface 1a of the aircraft 1 and discharging it rearward (X2 direction). The second propulsion unit 3 is configured to obtain propulsive force by rotating the rotor blades 30 using, for example, an electric drive unit (not shown). In other words, the second propulsion unit 3 is an electric propulsion unit. The rotor blades 30 include, for example, a fan or a propeller. The second propulsion unit 3 is an example of a "propulsion unit" as defined in the claims.

[0028] The heat exchanger 4 is a heat exchanger provided in the aircraft 100 that is equipped with a second propulsion unit 3 having rotor blades 30. The detailed configuration of the heat exchanger 4 will be described later.

[0029] (function block) As shown in FIG. 2, the aircraft 100 includes a first propulsion device 2, a second propulsion device 3, and a heat exchanger 4, as well as a control unit 5 and a control unit 6.

[0030] The control unit 5 is configured to control each unit of the aircraft 100. The control unit 5 is, for example, a computer including a processor such as a CPU (Central Processing Unit) and memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory).

[0031] The control unit 6 is configured to receive operational inputs from a pilot when flying the aircraft 100. The control unit 6 includes, for example, a control stick, control pedals, and the like.

[0032] (Heat exchanger configuration) Next, the configuration of the heat exchanger 4 will be described with reference to FIG.

[0033] 3, the heat exchanger 4 includes a base 40 and a plurality of heat dissipation fins 41 provided on the base 40. The base 40 and the plurality of heat dissipation fins 41 are examples of a "first base" and a "plurality of first heat dissipation fins," respectively.

[0034] The base 40 is provided on the inner circumferential surface 3a (see FIG. 4) of the second propulsion device 3 (see FIG. 4). In this embodiment, the base 40 is curved circumferentially along the inner circumferential surface 3a of the second propulsion device 3. The base 40 is made of, for example, aluminum or an aluminum alloy.

[0035] Furthermore, a flow path 42 through which a fluid to be subjected to heat exchange can flow is formed in the base portion 40. The fluid to be subjected to heat exchange is, for example, lubricating oil used in the second propulsion device 3.

[0036] 3, the flow path 42 extends along the circumferential direction of the base 40 (a direction intersecting with the plurality of heat dissipation fins 41). Note that the flow path 42 may also extend along the direction in which the plurality of heat dissipation fins 41 extend (the X direction).

[0037] Each of the multiple heat dissipation fins 41 has a structure that increases the area in contact with the airflow, for example, a rectangular shape. Specifically, each of the multiple heat dissipation fins 41 has a rectangular shape with a height H1, a width T1, and a length L1. The height H1 is the length from the base 40 toward the center of the second propulsion device 3. The width T1 is the length of each of the multiple heat dissipation fins 41 in the direction in which they are arranged. The length L1 is the length of each of the multiple heat dissipation fins 41 in the X direction. As shown in FIG. 3 , in this embodiment, each of the multiple heat dissipation fins 41 is provided on the base 40 so as to extend along the X direction with the height H1 and width T1 unchanged.

[0038] 3, the plurality of heat dissipation fins 41 are arranged at intervals P1. In other words, the arrangement pitch of the plurality of heat dissipation fins 41 is the interval P1.

[0039] 3, each of the heat dissipation fins 41 is provided on the base 40 so as to extend along the X direction. The side surface of each of the heat dissipation fins 41 has a structure that increases the area in contact with the airflow, for example, a rectangular shape. Each of the heat dissipation fins 41 is provided on the base 40 so as to extend in a direction perpendicular to the base 40 when viewed from the X direction. In this embodiment, since the base 40 is curved circumferentially, each of the heat dissipation fins 41 is provided on the base 40 so as to extend toward the center 40b of the base 40 (see FIG. 6).

[0040] In this embodiment, each of the plurality of heat dissipation fins 41 is made of, for example, aluminum or an aluminum alloy.

[0041] (Heat exchanger and rotor blade arrangement) 4, the heat exchanger 4 is provided on the inner circumferential surface 3a of the second propulsion unit 3, forward of the rotor blades 30 in the traveling direction of the aircraft 1 (on the X1 direction side). In other words, the base 40 is disposed on the inner circumferential surface 3a of the second propulsion unit 3, forward of the rotor blades 30 in the traveling direction of the aircraft 100.

[0042] Here, the second propulsion unit 3 sucks in the airflow that flows along the outer surface 1a of the airframe 1. Therefore, the total pressure of the airflow flowing into the rotor blades 30 varies depending on the position, as shown in total pressure distribution 80 in Fig. 5. In the example shown in Fig. 5, differences in total pressure are represented by different hatching, as shown in legend 81. The total pressure distribution 80 was obtained in advance through experiments.

[0043] A total pressure distribution 80 shown in Fig. 5 indicates the distribution of total pressure on the front surface of the rotor blades 30 of the second propulsion device 3. In the example shown in Fig. 5, the total pressure is high at positions on the front surface of the rotor blades 30 of the second propulsion device 3 on the Y1 direction side and the Z2 direction side, and at positions on the Y2 direction side and the Z2 direction side.

[0044] Therefore, in this embodiment, the height H1 of the plurality of heat dissipation fins 41 is changed in accordance with the total pressure distribution 80. Specifically, the height H1 of the plurality of heat dissipation fins 41 is changed so that the aerodynamic loss increases at positions in the total pressure distribution 80 where the total pressure is higher.

[0045] 6 and 7, in this embodiment, the plurality of heat dissipation fins 41 are configured so that the height H1 increases as the total pressure increases in a total pressure distribution 80 (see FIG. 5). Specifically, the plurality of heat dissipation fins 41 are configured so that the height H1 increases as the total pressure increases in a total pressure distribution 80 of the airflow that flows along the outer surface 1a of the fuselage 1 of the aircraft 100 and is sucked into the second propulsion unit 3.

[0046] 6 and 7, the height H1 of the heat dissipation fins 41 is configured to be larger at a position between the Y1 direction and the Z2 direction (region 50a indicated by the dashed line) and at a position between the Y2 direction and the Z2 direction (region 50b indicated by the dashed line). The height H1 of the heat dissipation fins 41 at a position between the regions 50a and 50b (region 51a indicated by the dashed line) and at positions on the Z1 direction side of the center 40b in the height direction (Z direction) of the base 40 (regions 51b and 51c indicated by the dashed line) are smaller than the height H1 of the heat dissipation fins 41 provided at the regions 50a and 50b. In this embodiment, the height H1 of the heat dissipation fins 41 changes gradually or in stages.

[0047] In addition, in this embodiment, the multiple heat dissipation fins 41 are used for both heat exchange between the fluid flowing through the flow path 42 (see Figure 5) and the air flowing between the multiple heat dissipation fins 41, and for rectifying the airflow flowing into the second propulsion device 3.

[0048] (Effects of this embodiment) In this embodiment, the following effects can be obtained.

[0049] In this embodiment, as described above, the heat exchanger 4 includes a base 40 and multiple heat dissipation fins 41. The base 40 is disposed forward of the rotor blades 30 in the direction of travel of the aircraft 100. The height H1 of the multiple heat dissipation fins 41 is changed according to the total pressure distribution 80 of the airflow flowing into the second propulsion unit 3. This allows the multiple heat dissipation fins 41 of the heat exchanger 4 to adjust the total pressure of the airflow flowing into the second propulsion unit 3. In other words, the multiple heat dissipation fins 41 can both cool the object to be cooled and suppress distortion of the airflow flowing into the second propulsion unit 3. Therefore, compared to a configuration including, for example, the heat exchanger 4 and a component separate from the heat exchanger 4 that adjusts the total pressure of the airflow flowing into the second propulsion unit 3, an increase in the number of parts of the aircraft 100 can be suppressed. As a result, it is possible to achieve both cooling of the object to be cooled and suppression of distortion of the airflow flowing into the second propulsion unit 3 while suppressing an increase in the number of parts of the aircraft 100.

[0050] Furthermore, in this embodiment, as described above, the height H1 of the multiple heat dissipation fins 41 is changed so that aerodynamic loss increases at positions where the total pressure is higher in the total pressure distribution 80. Here, if distortion occurs in the airflow flowing into the second propulsion device 3, the efficiency of the rotor blades 30 provided in the second propulsion device 3 decreases, the noise of the rotor blades 30 increases due to the distortion, and the risk of fatigue failure of the rotor blades 30 increases due to an increase in cyclic load on the rotor blades 30. This can result in an increase in the energy consumption of the aircraft 100, an increase in the environmental impact of the aircraft 100, and a decrease in the reliability of the aircraft 100. Therefore, by configuring as described above, the multiple heat dissipation fins 41 can increase the aerodynamic loss at positions where the total pressure is high, thereby making the total pressure distribution 80 uniform. In other words, it is possible to reduce distortion of the airflow in front of the rotor blades 30 of the second propulsion device 3. Therefore, it is possible to suppress a decrease in the efficiency of the rotor blades 30 of the second propulsion device 3. This can improve the efficiency of the rotor blades 30 of the second propulsion device 3. As a result, an increase in the energy consumption of the aircraft 100 can be suppressed. Furthermore, because distortion of the airflow in front of the rotor blades 30 of the second propulsion device 3 is reduced, noise from the rotor blades 30 caused by distortion occurring in the second propulsion device 3 can be reduced. As a result, the environmental impact of the aircraft 100 can be reduced. Furthermore, because it is possible to uniformly distribute the total pressure, an increase in cyclic load on the rotor blades 30 can be suppressed. As a result, it is possible to reduce the risk of fatigue failure in the rotor blades 30 of the second propulsion device 3, and the reliability of the aircraft 100 can be improved.

[0051] Furthermore, in this embodiment, as described above, the multiple heat dissipation fins 41 are configured so that the height H1 increases as the total pressure increases in the total pressure distribution 80 of the airflow sucked into the second propulsion unit 3, including the flow interfering with the outer surface 1a of the fuselage 1 of the aircraft 100. Here, the airflow including the flow interfering with the outer surface 1a of the fuselage 1 of the aircraft 100 is more turbulent than the airflow passing under the wings of the aircraft 100. Therefore, the airflow sucked into the second propulsion unit 3, including the flow interfering with the outer surface 1a of the fuselage 1 of the aircraft 100, has a distorted airflow distribution. Therefore, with the above configuration, the height H1 of the heat dissipation fins 41 increases as the total pressure increases. Therefore, by changing the area of ​​each heat dissipation fin 41 and the speed of the airflow acting on each heat dissipation fin 41 at the position of high total pressure, aerodynamic phenomena can be adjusted, thereby effectively controlling aerodynamic loss. Therefore, it is possible to effectively reduce distortion of the airflow taken into the second propulsion device 3, including the flow interfering with the outer surface 1a of the fuselage 1 of the aircraft 100. As a result, it is possible to effectively suppress a decrease in the efficiency of the rotor blades 30 of the second propulsion device 3, an increase in the noise of the rotor blades 30 due to distortion, and an increase in the cyclic load on the rotor blades 30. As a result, it is possible to provide a heat exchanger 4 that can effectively suppress an increase in the energy consumption of the aircraft 100, effectively reduce the environmental load of the aircraft 100, and effectively improve the reliability of the aircraft 100.

[0052] Furthermore, in this embodiment, as described above, the height H1 of the multiple fins 41 is increased as the total pressure increases in the total pressure distribution 80. Increasing the height H1 of the multiple fins 41 allows the area of ​​each fin 41, as viewed from the X1 direction, and the speed of the airflow acting on each fin 41, to be adjusted according to the height of the fin 41. This allows aerodynamic phenomena to be adjusted, thereby controlling aerodynamic losses at positions where the total pressure is high. This facilitates reducing distortion of the airflow flowing into the second propulsion unit 3. Increasing the height H1 of the fins 41 also increases the heat transfer area between the fin 41 and the airflow, thereby improving heat exchange capacity. As a result, a heat exchanger 4 can be provided that simultaneously reduces distortion of the airflow flowing into the second propulsion unit 3 and ensures a sufficient amount of heat dissipation in the heat exchanger 4.

[0053] Furthermore, in this embodiment, as described above, the base 40 is formed with a flow path 42 through which a fluid to be subjected to heat exchange can flow, and the multiple radiator fins 41 are used for both heat exchange between the fluid flowing through the flow path 42 and the air flowing between the multiple radiator fins 41, and for rectifying the airflow flowing into the second propulsion unit 3. As a result, since the base 40 is formed with the flow path 42 through which a fluid can flow, heat exchange can be performed between a fluid such as lubricating oil and the airflow, for example. As a result, compared to a configuration including the heat exchanger 4 and a member, separate from the heat exchanger 4, that adjusts the total pressure of the airflow flowing into the second propulsion unit 3, it is possible to cool a fluid such as lubricating oil while minimizing an increase in the number of parts of the aircraft 100.

[0054] Furthermore, in this embodiment, as described above, the aircraft 100 includes the airframe 1, the second propulsion unit 3 having the rotor blades 30, and the heat exchanger 4 having a plurality of heat dissipation fins 41 and located forward of the rotor blades 30 in the direction of travel of the airframe 1. The height H1 of the plurality of heat dissipation fins 41 is changed in accordance with the total pressure distribution 80 of the airflow flowing into the second propulsion unit 3. This makes it possible to provide an aircraft 100 that, like the heat exchanger 4 described above, can simultaneously cool the object to be cooled and suppress distortion of the airflow flowing into the second propulsion unit 3 while suppressing an increase in the number of parts.

[0055] Furthermore, in this embodiment, as described above, the height H1 of the multiple heat dissipation fins 41 is changed so that the aerodynamic loss increases at positions with higher total pressure within the total pressure distribution 80. This, like the heat exchanger 4 described above, makes it possible to suppress a decrease in the efficiency of the rotor blades 30 of the second propulsion device 3, an increase in the noise of the rotor blades 30, and an increase in the cyclic load on the rotor blades 30, thereby also making it possible to provide an aircraft 100 that is able to suppress an increase in energy consumption, reduce environmental loads, and improve reliability.

[0056] Furthermore, in this embodiment, as described above, the multiple heat dissipation fins 41 include a flow that interferes with the outer surface 1a of the airframe 1, and are configured so that the height H1 increases as the total pressure increases in the total pressure distribution 80 of the airflow sucked into the second propulsion unit 3. This makes it possible, similar to the heat exchanger 4 described above, to effectively suppress a decrease in the efficiency of the rotor blades 30 of the second propulsion unit 3, an increase in the noise of the rotor blades 30 due to distortion, and an increase in the cyclic load on the rotor blades 30. Therefore, it is possible to provide an aircraft 100 that can effectively suppress an increase in energy consumption, effectively reduce environmental load, and effectively improve reliability.

[0057] Furthermore, in this embodiment, as described above, the plurality of heat dissipation fins 41 are configured so that the height H1 increases as the total pressure increases within the total pressure distribution 80. This makes it possible to provide an aircraft 100 that, like the heat exchanger 4 described above, achieves both reduced distortion of the airflow flowing into the second propulsion device 3 and a sufficient amount of heat dissipation in the heat exchanger 4.

[0058] Furthermore, in this embodiment, as described above, the base 40 is formed with a flow path 42 through which a fluid to be subjected to heat exchange can flow, and the multiple heat dissipation fins 41 are used for both heat exchange between the fluid flowing through the flow path 42 and the air flowing between the multiple heat dissipation fins 41, and for rectifying the airflow entering the second propulsion unit 3. This makes it possible to provide an aircraft 100 that can cool fluids such as lubricating oil while suppressing an increase in the number of parts, similar to the heat exchanger 4 described above.

[0059] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0060] (First Modification) For example, in the above embodiment, an example of a configuration in which the aircraft 100 includes one heat exchanger 4 has been described, but the present invention is not limited to this. For example, in a first modified example shown in Fig. 8, the aircraft 200 further includes a second heat exchanger 7 in addition to the first propulsion device 2, the second propulsion device 3, the heat exchanger 4, the control unit 5, and the control unit 6.

[0061] As shown in FIG. 8, the second heat exchanger 7 according to the first modified example is provided forward of the second propulsion device 3 in the traveling direction (X1 direction side).

[0062] As shown in FIG. 9, the second heat exchanger 7 has a second base 70 and a plurality of second heat dissipation fins 71.

[0063] The second base 70 has a shape that fits the outer surface 1a of the fuselage 1. The second base 70 is made of aluminum or an aluminum alloy. No flow path is formed in the second base 70. In other words, the second heat exchanger 7 is a heat sink.

[0064] The second heat dissipation fins 71 are provided on the second base 70. Each of the second heat dissipation fins 71 has a structure, such as a rectangular shape, that increases the area of ​​contact with the airflow. Specifically, each of the second heat dissipation fins 71 has a rectangular shape with a height H2, a width T2, and a length L2. The height H2 is the length from the second base 70 toward the outside of the body 1. The width T2 is the length of each of the second heat dissipation fins 71 in the direction in which the second heat dissipation fins 71 are arranged. The length L2 is the length of each of the second heat dissipation fins 71 in the X direction. As shown in FIG. 9 , in this embodiment, each of the second heat dissipation fins 71 is provided on the second base 70 so as to extend along the X direction with the height H2 and width T2 unchanged in the X direction.

[0065] 9, the second heat dissipating fins 71 are arranged at intervals P2. In other words, the second heat dissipating fins 71 are arranged at intervals P2.

[0066] As shown in FIG. 9, each of the plurality of second heat dissipation fins 71 is provided on the second base portion 70 so as to extend along the X direction.

[0067] Also, as shown in FIG. 9, the multiple second heat dissipation fins 71 are configured so that each has a uniform height H2 and a smaller height H2 than the heat dissipation fin 41 that is positioned at a position where the total pressure is higher among the multiple heat dissipation fins 41.

[0068] The other configurations of the first modified example are the same as those of the above embodiment.

[0069] (Effects of the first modified example) In the first modified example, as described above, the aircraft 200 further includes a second heat exchanger 7 having a plurality of second heat dissipation fins 71. The second heat exchanger 7 is provided forward of the second propulsion unit 3 in the direction of travel. As a result, the airflow that has been rectified to a certain extent by the second heat exchanger 7, which is provided forward of the second propulsion unit 3, is further rectified by the heat exchanger 4, thereby more effectively reducing distortion of the airflow flowing into the second propulsion unit 3. As a result, it is possible to more effectively suppress a decrease in the efficiency of the rotor blades 30 of the second propulsion unit 3 and an increase in noise from the rotor blades 30 due to distortion, so it is possible to more effectively suppress an increase in the energy consumption of the aircraft 200 and an increase in the environmental load of the aircraft 200. Furthermore, it is possible to more effectively suppress an increase in cyclic load on the rotor blades 30, so it is possible to more effectively improve the reliability of the aircraft 200.

[0070] Furthermore, in the first modification, as described above, the plurality of heat dissipation fins 41 are configured so that the height H1 increases as the total pressure increases in the total pressure distribution 80 of the airflow sucked into the second propulsion unit 3, and the plurality of second heat dissipation fins 71 are configured so that each has a uniform height H2 and is smaller than the height H2 of the heat dissipation fins 41 that are arranged in positions of higher total pressure among the plurality of heat dissipation fins 41. This makes it possible to set the shape of the plurality of second heat dissipation fins 71 so as to reduce distortion that occurs when airflow, including a flow that has interfered with the fuselage 1 of the aircraft 200, reaches the front of the rotor blades 30 of the second propulsion unit 3. As a result, the combination of the plurality of heat dissipation fins 41 and the plurality of second heat dissipation fins 71 can reduce distortion.

[0071] (Second Modification) Furthermore, in the above embodiment, an example of an aircraft 100 equipped with one second propulsion unit 3 has been described, but the present invention is not limited to this. For example, as in the aircraft 300 according to a second modified example shown in Fig. 10, the aircraft 300 may be equipped with a plurality of second propulsion units 301, for example, twin second propulsion units 301. In this case, the aircraft 300 may be equipped with a heat exchanger 302 provided on the inner circumferential surface of each of the twin second propulsion units 301. Each of the twin heat exchangers 302 may be disposed forward (in the X1 direction) of the rotor blades 303 of each of the second propulsion units 301.

[0072] In the second modified example, as shown in FIG. 11, the heat exchanger 302 has multiple heat dissipation fins 304. In the second propulsion device 301 according to the second modified example, the total pressure is higher at the outer positions than at the inner positions. Therefore, as shown in FIG. 11, the multiple heat dissipation fins 304 of the heat exchanger 302 provided on the second propulsion device 301a on the Y1 side of the second propulsion device 301 have a larger height H1 at the Y1 side (region 50c shown by the dashed line). Furthermore, the multiple heat dissipation fins 304 of the heat exchanger 302 provided on the second propulsion device 301a on the Y1 side of the second propulsion device 301 have a smaller height H1 at the Y2 side (region 51d shown by the dashed line).

[0073] 11, the heat dissipation fins 304 of the heat exchanger 302 provided on the second propulsion unit 301b on the Y2 side of the second propulsion unit 301 have a larger height H1 at a position on the Y2 side (region 50d shown by the dashed line).The heat dissipation fins 304 of the second propulsion unit 301b on the Y2 side of the second propulsion unit 301 have a smaller height H1 at a position on the Y1 side (region 51f shown by the dashed line).

[0074] (Third Modification) Furthermore, in the above embodiment, an example has been shown in which the aircraft 100 is configured to include a first propulsion unit 2 provided under the wing and a second propulsion unit 3 provided at the rear of the fuselage 1, but the present invention is not limited to this. For example, as in the aircraft 400 according to a third modified example shown in FIG. 12 , a plurality of propulsion units 401, for example, twin propulsion units 401, may be provided at the rear (X2 direction side) of the fuselage 1. In this case, the aircraft 400 only needs to include a heat exchanger 402 provided on the inner circumferential surface of each of the two propulsion units 401. Each of the two heat exchangers 402 may be located forward (X1 direction side) of the rotor blades 403 of each of the two propulsion units 401. The two propulsion units 401 are each embedded in the fuselage 1.

[0075] In the third modified example, as shown in FIG. 13, the heat exchanger 402 has a plurality of heat dissipation fins 404. In the propulsion device 401 according to the third modified example, the total pressure is higher at outer and upper positions than at other positions. Therefore, as shown in FIG. 13, the height H1 of the plurality of heat dissipation fins 404 of the heat exchanger 402 provided in the propulsion device 401a on the Y1 direction side of the propulsion device 401 is larger at positions on the Y1 direction side and the Z1 direction side (region 50e shown by the dashed line). Furthermore, the height H1 of the plurality of heat dissipation fins 404 of the heat exchanger 402 provided in the propulsion device 401a on the Y1 direction side of the propulsion device 401 is smaller at positions (regions 51f and 51g shown by the dashed line) other than the position on the Y1 direction side and the Z2 direction side (region 50e shown by the dashed line).

[0076] 13, the heat dissipation fins 404 of the heat exchanger 402 provided in the propulsion device 401b on the Y2 side of the propulsion device 401 have a larger height H1 at a position on the Y2 side and the Z1 side (region 50f shown by the dashed line). The heat dissipation fins 404 of the heat exchanger 402 provided in the propulsion device 401b on the Y2 side of the propulsion device 401 have a smaller height H1 at positions (regions 51h and 51i shown by the dashed line) other than the position on the Y2 side and the Z2 side (region 50g shown by the dashed line).

[0077] (Fourth Modification) Furthermore, in the above embodiment, an example of a configuration in which the aircraft 100 includes a first propulsion unit 2 and a second propulsion unit 3, and the heat exchanger 4 is provided on the inner circumferential surface 3a of the second propulsion unit 3, has been described. However, the present invention is not limited to this. For example, as in the aircraft 500 according to a fourth modified example shown in FIG. 14 , a heat exchanger 502 may be provided on the inner circumferential surface of each of multiple propulsion units 501 of a blended wing body (BWB) aircraft in which the main wings 10 are integrated with the fuselage 1. In this case, too, the heat exchanger 502 only needs to be disposed forward (in the X1 direction) of the rotor blades 503 of each of the multiple propulsion units 501. Furthermore, the aircraft 500 according to the fourth modified example is provided with a second heat exchanger 504 in front of the multiple propulsion units 501. The configuration of the second heat exchanger 504 is similar to that of the second heat exchanger 7 according to the first modified example, and therefore a detailed description thereof will be omitted.

[0078] In each of the multiple propulsion devices 501 according to the fourth modification, the total pressure is higher at the upper position than at other positions. Therefore, as shown in Fig. 15, the multiple heat dissipation fins 505 of the heat exchanger 502 provided in the propulsion device 501a have a larger height H1 at a position on the Z1 direction side (region 50g shown by the dashed line). Furthermore, the multiple heat dissipation fins 505 provided in the heat exchanger 502 of the propulsion device 501a have a smaller height H1 at positions (regions 51j, 51k, and 51l shown by the dashed lines) other than the position on the Z1 direction side (region 50g shown by the dashed line).

[0079] 15, the heat dissipation fins 505 of the heat exchanger 502 provided in the propulsion device 501b have a larger height H1 at a position on the Z1 direction side (region 50h indicated by the dashed line). The heat dissipation fins 505 of the heat exchanger 502 provided in the propulsion device 501b have a smaller height H1 at positions (regions 51m, 51n, and 51o indicated by the dashed line) other than the position on the Z1 direction side (region 50h indicated by the dashed line). Note that, for convenience, the example shown in FIG. 15 shows only the propulsion devices 501a and 501b out of the multiple propulsion devices 501; however, the height H1 of the heat dissipation fins 505 of the heat exchangers 502 provided on the inner circumferential surfaces of the other propulsion devices 501 is similarly changed.

[0080] (Fifth Modification) Furthermore, in the above embodiment, an example of a configuration in which the heat exchanger 4 is provided on the inner circumferential surface 3a of the second propulsion unit 3 has been described, but the present invention is not limited to this. For example, as in an aircraft 600 according to a fifth modified example shown in Fig. 16, the heat exchanger 601 may be provided on the first propulsion unit 2. In this case as well, the heat exchanger 601 only needs to be located forward (on the X1 direction side) of the rotor blades 20 of the multiple first propulsion units 2.

[0081] In each of the multiple first propulsion units 2 according to the fifth modification, the total pressure is higher at the upper position than at other positions. Therefore, as shown in Fig. 17, the multiple heat dissipation fins 602 of the heat exchanger 601 provided in the first propulsion unit 2a have a larger height H1 at a position on the Z1 direction side (region 50i shown by the dashed line). Furthermore, the multiple heat dissipation fins 602 of the heat exchanger 601 provided in the first propulsion unit 2a have a smaller height H1 at positions (regions 51o and 51p shown by the dashed line) other than the position on the Z1 direction side (region 50i shown by the dashed line).

[0082] 17, the heat dissipation fins 602 of the heat exchanger 601 provided in the first propulsion unit 2b have a larger height H1 at a position on the Z1 direction side (region 50j shown by the dashed line).The heat dissipation fins 602 of the heat exchanger 601 provided in the first propulsion unit 2b have a smaller height H1 at positions (regions 51q and 51r shown by the dashed line) other than the position on the Z1 direction side (region 50j shown by the dashed line).

[0083] (Sixth Modification) In the above embodiment, an example of a configuration in which the height H1 of the plurality of heat dissipation fins 41 is changed in accordance with the total pressure distribution 80 has been described, but the present invention is not limited to this. For example, as in a heat exchanger 140 of a sixth modified example shown in Fig. 18, the spacing P1 between the plurality of heat dissipation fins 41 may be changed in accordance with the total pressure distribution 80.

[0084] 18, the spacing between the heat dissipation fins 41 in regions 50k and 50l is changed to spacing P3, which is narrower than spacing P1. With this configuration, it is possible to control aerodynamic losses in regions 50k and 50l by adjusting aerodynamic phenomena by changing the area of ​​the heat dissipation fins 41 and the speed of the airflow acting on the heat dissipation fins 41 in regions 50k and 50l, thereby achieving effects similar to those of the heat exchanger and aircraft according to the above-described embodiment.

[0085] (Seventh Modification) Furthermore, in the above embodiment, an example of a configuration in which the height H1 of the plurality of heat dissipation fins 41 is changed in accordance with the total pressure distribution 80 has been described, but the present invention is not limited to this. For example, as in a heat exchanger 141 of a seventh modified example shown in Fig. 19, the shape of the plurality of heat dissipation fins 41 may be changed in accordance with the total pressure distribution 80. The heat exchanger 141 according to the seventh modified example has a plurality of heat dissipation fins 41 and a plurality of heat dissipation fins 141a with different widths.

[0086] 19, in regions 50m and 50n, a plurality of heat dissipation fins 141a having a width T3 larger than the width T1 of the plurality of heat dissipation fins 41 are arranged. With this configuration, it is possible to adjust the aerodynamic phenomenon by changing the area of ​​the plurality of heat dissipation fins 141a in regions 50m and 50n. Therefore, it is possible to control aerodynamic loss in regions 50m and 50n, thereby achieving the same effects as the heat exchanger and aircraft according to the above embodiment.

[0087] (Eighth Modification) Furthermore, in the above embodiment, when changing the height H1 of the plurality of heat dissipation fins 41 in accordance with the total pressure distribution 80, an example of a configuration in which the heights are changed in both the X1 and X2 directions is described. However, the present invention is not limited to this. For example, when the heat dissipation fins 142a of the heat exchanger 142 of the eighth modification shown in FIG. 20 are disposed in a position where the total pressure is high, the height H3 of the heat dissipation fins 142a on the X2 direction side may be greater than the height H1 of the X1 direction side. With this configuration, as the height H1 of the heat dissipation fins 142a increases to height H3, the area of ​​each heat dissipation fin 142a and the speed of the airflow acting on each heat dissipation fin 142a can be changed to adjust aerodynamic phenomena. Therefore, since it is possible to control aerodynamic losses at positions where the total pressure is high, the same effects as those of the heat exchanger and aircraft according to the above embodiment can be achieved. Furthermore, when the heat dissipation fins 142a are disposed in a position where the total pressure is high, the height H1 of the X1 direction side may be increased and the height H3 of the heat dissipation fins 142a on the X2 direction side may be decreased.

[0088] (Ninth Modification) In addition, in the above embodiment, an example of a configuration in which the height H1 of the plurality of heat dissipation fins 41 is changed in accordance with the total pressure distribution 80 has been described, but the present invention is not limited to this. For example, as in a heat exchanger 143 of a ninth modified example shown in FIG. 21 , the shape of the plurality of heat dissipation fins 41 may be changed in accordance with the total pressure distribution 80.

[0089] In the example shown in FIG. 21, a plurality of heat dissipation fins 143a having a different shape from the plurality of heat dissipation fins 41 are arranged in the regions 50o and 50p. The plurality of heat dissipation fins 143a have a shape in which a width T4 on the base 40 side is greater than a width T1 on the opposite side from the base 40. That is, the plurality of heat dissipation fins 143a have a trapezoidal shape. With this configuration, aerodynamic phenomena can be adjusted by changing the area of ​​each heat dissipation fin 143a in the regions 50o and 50p. Therefore, aerodynamic losses in the regions 50o and 50p can be controlled, thereby achieving the same effects as the heat exchanger and aircraft according to the above-described embodiment.

[0090] (Tenth Modification) In the above embodiment, the height H1 of the heat dissipation fins 41 is changed gradually in accordance with the total pressure distribution 80. However, the present invention is not limited to this. In the present invention, the height H1 of the heat dissipation fins 41 does not have to be changed gradually or in stages when changing the height H1 between positions where the total pressure is high and low. For example, as in a heat exchanger 144 of a tenth modification shown in FIG. 22, a plurality of heat dissipation fins 144a having a height H4 greater than the height H1 of the heat dissipation fins 41 may be arranged in the regions 50q and 50r.

[0091] (Eleventh Modification) In the above embodiment, an example of a configuration in which each of the plurality of heat dissipation fins 41 is formed to extend in a direction perpendicular to the base 40 has been described, but the present invention is not limited to this. For example, as in a heat exchanger 145 of an eleventh modified example shown in Fig. 23, each of the plurality of heat dissipation fins 41 may be formed so that the predetermined angle θ1 with respect to the base 40 is an angle other than a right angle (90 degrees) when viewed from the X direction.

[0092] In this case, as shown in FIG. 23, the height of the heat dissipation fins 41 can be increased in regions where the total pressure of the airflow is high. Specifically, as shown in FIG. 23, multiple heat dissipation fins 145a are arranged in regions 50s and 50t. The multiple heat dissipation fins 145a are formed so that the height H5 of the multiple heat dissipation fins 145a is greater than the height H1 of the multiple heat dissipation fins 41. Even in this manner, aerodynamic phenomena can be adjusted by changing the area of ​​each heat dissipation fin 145a in regions 50s and 50t and by changing the speed of the airflow acting on each heat dissipation fin 145a. Therefore, since it is possible to control aerodynamic losses in regions 50s and 50t, the same effects as those of the heat exchanger and aircraft according to the above embodiment can be obtained.

[0093] (Twelfth Modification) Furthermore, while the above embodiment has shown an example of a configuration in which multiple heat dissipation fins 41 are provided on the base 40 along the X direction, the present invention is not limited to this. For example, as in a heat exchanger 146 of a twelfth modification shown in FIG. 24 , among the multiple heat dissipation fins, a heat dissipation fin 146a that is located at a position where the total pressure of the airflow is high may be formed on the base 40 with the base 40 tilted by a predetermined angle θ2 when viewed from the Z direction. This configuration makes it possible to adjust aerodynamic phenomena by changing the area of ​​each of the multiple heat dissipation fins 146a, thereby controlling aerodynamic loss on the front surface of the rotor blade 30 in the region where the multiple heat dissipation fins 146a are provided. As a result, the same effects as those of the heat exchanger and aircraft in the above embodiment can be obtained.

[0094] (13th Modification) Although the above embodiment illustrates an example in which the lengths L1 of the heat dissipation fins 41 are equal to one another, the present invention is not limited to this. For example, as in the heat exchanger 147 of a thirteenth modification shown in FIG. 25 , the length L3 of the heat dissipation fin 147a, which is located at a position where the total airflow pressure is high, may be longer than the length L1 of the heat dissipation fin 41. Alternatively, the lengths of the heat dissipation fins 41 may be shorter than the length L1, and the length of the heat dissipation fin 147a located at a position where the total airflow pressure is high may be set to the length L1. Note that if the length L3 of the heat dissipation fins 147a is changed to a length different from the length L1 of the heat dissipation fin 41, the shape of the side surface of the heat dissipation fin is changed. In other words, changing the length of the heat dissipation fin is also included in changing the shape of the heat dissipation fin. This configuration makes it possible to adjust aerodynamic phenomena by changing the speed of the airflow acting on each of the heat dissipation fins 147a, thereby controlling aerodynamic loss on the front surface of the rotor blade 30 in the area where the heat dissipation fins 147a are provided. As a result, the same effects as those of the heat exchanger and aircraft in the above-described embodiment can be obtained.

[0095] (14th Modification) Furthermore, in the above embodiment, an example of a configuration in which the heat exchanger 4 has the flow path 42 through which the fluid to be heat exchanged can flow is shown, but the present invention is not limited to this. For example, the heat exchanger does not have to have a flow path. That is, as in a fourteenth modification shown in FIG. 26 , the heat exchanger 148 may be a heat sink that cools an object to be cooled 90 provided on the outer surface. The object to be cooled 90 includes, for example, a semiconductor portion of a power converter, a control circuit, and a pump.

[0096] As shown in FIG. 27 , a heat exchanger 148 according to the fourteenth modification includes a base 148a and a plurality of heat dissipation fins 148b. The plurality of heat dissipation fins 148b are provided on the inner circumferential surface of the base 148a. Furthermore, a plurality of objects to be cooled 90 are provided on the outer surface of the base 148a. As in the above embodiment, the heat dissipation fins 148b according to the fourteenth modification, which are located at positions where the total pressure is high, are configured to be tall. This configuration allows aerodynamic phenomena to be adjusted by changing the area of ​​the tallest heat dissipation fins among the plurality of heat dissipation fins 148b and the speed of the airflow acting on each of the tallest heat dissipation fins among the plurality of heat dissipation fins 148b. Therefore, aerodynamic loss on the front surface of the rotor blade 30 can be controlled in the region where the total pressure is high, where the plurality of heat dissipation fins 148b are provided. As a result, the same effects as those of the heat exchanger and aircraft according to the above embodiment can be achieved while cooling the objects to be cooled 90, such as semiconductor components and control circuits, without circulating fluid through the base 148a.

[0097] (Other variations) In the above embodiment, the height H1 of each of the plurality of heat dissipation fins 41 arranged at a position where the total pressure is high is greater than the height H1 of each of the heat dissipation fins 41 arranged at a position where the total pressure is low, but the present invention is not limited to this. For example, each of the plurality of heat dissipation fins may be arranged so that the height of each of the heat dissipation fins arranged at a position where the total pressure is low is smaller than the height of each of the heat dissipation fins arranged at a position where the total pressure is high.

[0098] In the above embodiment, the heat dissipation fins 41 have one end abutting the base 40 in the height direction and the other end free of any components, but the present invention is not limited to this. For example, the heat dissipation fins may further include a plate-like member abutting the other end in the height direction.

[0099] In the above embodiment, the heat dissipation fins 41 are configured to extend linearly along the X direction, but the present invention is not limited to this. For example, the heat dissipation fins may have an undulating (snake) shape along the width direction.

[0100] Furthermore, the heat dissipation fins 41 may have any combination of height H1, shape, spacing P1, and angle θ2 relative to the base 40 changed depending on the total pressure distribution 80. In this case, the height H1, shape, spacing P1, and angle θ2 may be changed in any combination. Alternatively, all of the height H1, shape, spacing P1, and angle θ2 may be changed.

[0101] In addition, in the above embodiment, an example of a configuration in which the heat exchanger 4 and the base 40 are provided on the inner circumferential surface 3a of the second propulsion unit 3 has been shown, but the present invention is not limited to this. The heat exchanger and the base may be provided at a position other than the inner circumferential surface of the second propulsion unit, as long as they are provided in front of the rotor blades of the second propulsion unit.

[0102] Although the first modification described above illustrates an example in which the second heat exchanger 7 includes multiple second fins 71 with the same shape and spaced apart at intervals P2, the present invention is not limited to this configuration. Similar to the multiple second fins of the first heat exchanger, the multiple second fins of the second heat exchanger may be modified in terms of height, shape, angle relative to the base, and spacing so as to increase aerodynamic loss in areas where the total airflow pressure is high. By adjusting the height of the multiple second fins to change the area of ​​the multiple second fins and the speed of the airflow acting on the multiple second fins, aerodynamic loss can be controlled, thereby reducing airflow distortion. Furthermore, by adjusting the shape of the multiple second fins to change at least one of the area of ​​the multiple second fins and the speed of the airflow acting on the multiple second fins, aerodynamic loss can be controlled, thereby reducing airflow distortion. Furthermore, by adjusting the angle of each of the second fins relative to the base so as to change the speed of the airflow acting on the second fins, aerodynamic phenomena can be adjusted, thereby controlling aerodynamic loss and reducing airflow distortion. Furthermore, by reducing the spacing between the second fins, the area of ​​the second fins and the speed of the airflow acting on the second fins can be changed. Therefore, by adjusting aerodynamic phenomena, aerodynamic loss can be controlled, thereby reducing airflow distortion. Furthermore, because distortion can be reduced, an increase in cyclic load on the rotor blades can be suppressed.

[0103] In the first modified example, the height H2 of the second heat dissipation fins 71 is smaller than the height of the heat dissipation fin 41 arranged at a position where the total pressure is high among the multiple heat dissipation fins 41 according to the embodiment, but the present invention is not limited to this. For example, the height of the second heat dissipation fins may be the same as or greater than the height of the heat dissipation fin arranged at a position where the total pressure is high among the multiple heat dissipation fins according to the embodiment.

[0104] Furthermore, the side shapes of the heat dissipation fins of the first heat exchanger and the second heat dissipation fins of the second heat exchanger that are arranged in areas where the total pressure is high may be any shape as long as it is possible to control aerodynamic losses by adjusting the aerodynamic phenomenon by changing the speed of the airflow acting on the heat dissipation fins.

[0105] Furthermore, in the above embodiment, an example of a configuration in which the aircraft 100 is equipped with a first propulsion device 2 and a second propulsion device 3 has been described, but the present invention is not limited to this. For example, the aircraft does not have to be equipped with a second propulsion device. In this case, a heat exchanger having a configuration similar to that of the above embodiment may be provided on the inner circumferential surface of the first propulsion device. In a configuration in which a heat exchanger is provided on the inner circumferential surface of the first propulsion device, the "first propulsion device" is an example of a "propulsion device" in the claims. [Explanation of symbols]

[0106] 1 aircraft 1a Outer surface (surface of the aircraft) 3, 301, 401, 501, 501a, 501b 2nd propulsion device (propulsion device) 3a Inner surface (inner surface of the propulsion device) 4, 140, 141, 142, 143, 144, 145, 146, 147, 148,303, 403, 503, 601 Heat exchanger (1st heat exchanger) 7, 504 Second heat exchanger 30, 302, 402, 502 rotor blades (rotor blades of the propulsion device) 40, 148a base 41, 140a, 141a, 142a, 143a, 144a, 145a, 146a, 147a, 148b, 304, 404, 505, 602 Multiple heat dissipation fins 42 Flow path (flow path through which the liquid to be heat exchanged can flow) 80 Total pressure distribution 100, 200, 300, 400, 500, 600 aircraft H1, H3, H4, H5 Heat sink height H2 Height of the second heat dissipation fin P1 The distance between multiple heat sinks θ2 Angle relative to the base

Claims

1. A heat exchanger provided in an aircraft having a propulsion device with rotor blades, A base and a plurality of heat dissipation fins provided on the base; the base is disposed forward of the rotor blade in a direction of travel of the aircraft, a heat exchanger in which at least one of the height, shape, angle relative to the base, and spacing of the plurality of heat dissipation fins is changed so that when the plurality of heat dissipation fins are not arranged, the aerodynamic loss increases at positions where the total pressure is higher in the distribution of the total pressure on the front surface of the rotor blade of the airflow flowing into the propulsion device.

2. 2. The heat exchanger according to claim 1, wherein at least one of the height, shape, angle relative to the base, and spacing of the plurality of heat dissipation fins is changed so that aerodynamic loss increases at positions where the total pressure is higher in the distribution of the total pressure of the airflow sucked into the propulsion device, including flow that interferes with the aircraft fuselage.

3. The heat exchanger according to claim 2 , wherein the plurality of heat dissipation fins are configured so that the height of the fins increases as the total pressure increases in the distribution of the total pressure.

4. a flow path through which a fluid to be subjected to heat exchange can flow is formed in the base portion; 2. The heat exchanger according to claim 1, wherein the plurality of heat dissipation fins are used for both heat exchange between the fluid flowing through the flow path and air flowing between the plurality of heat dissipation fins and for rectifying the airflow flowing into the propulsion device.

5. The aircraft and a propulsion device mounted on the airframe and having rotor blades; a first heat exchanger having a first base and a plurality of first heat dissipation fins provided on the first base; the first heat exchanger is provided forward of the rotor blades in a traveling direction of the airframe, an aircraft in which the height, shape, angle relative to the first base, and spacing of the plurality of first heat dissipation fins are modified so that when the plurality of first heat dissipation fins are not arranged, the aerodynamic loss increases at positions where the total pressure is higher in the distribution of total pressure on the front surface of the rotor blade of the airflow flowing into the propulsion device.

6. 6. The aircraft according to claim 5, wherein the plurality of first heat dissipation fins include a flow that interferes with the airframe, and at least one of a height, a shape, an angle relative to the first base, and an interval at which the fins are arranged is changed so that aerodynamic loss increases at positions where the total pressure is higher in the distribution of the total pressure of the airflow sucked into the propulsion device.

7. The aircraft according to claim 6 , wherein the plurality of first heat dissipation fins are configured so that their height increases as the total pressure increases in a position within the total pressure distribution.

8. a flow path through which a fluid to be subjected to heat exchange can flow is formed in the first base portion; 6. The aircraft according to claim 5, wherein the plurality of first heat dissipation fins are used for both heat exchange between the fluid flowing through the flow path and air flowing between the plurality of first heat dissipation fins and rectifying airflow flowing into the propulsion device.

9. a second heat exchanger provided on the fuselage and having a second base and a plurality of second heat dissipation fins provided on the second base; The aircraft according to claim 5 , wherein the second heat exchanger is provided forward of the propulsion device in the direction of travel.

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