Intake system for an auxiliary power unit and auxiliary power unit

Abstract

The application relates to an air intake system of an auxiliary power unit, comprising: an air intake door, which is attached to the fuselage of an aircraft and can rotate between an open position and a closed position; an air intake passage, which is arranged downstream of the air intake door to guide air entering through the air intake door to an air intake component of the auxiliary power unit; a partition passage, which is arranged in front of the air intake door along the fuselage of the aircraft and can move between an open position and a closed position; a cooling pipe, which is arranged downstream of the partition passage to guide air entering through the partition passage to a cooling component of the auxiliary power unit; and an actuating device, which is attached to the air intake door and the partition passage to control the opening and closing of the air intake door and the partition passage. By arranging the partition passage, the influence of the boundary layer of the airflow on the air intake system can be effectively isolated, so that the air intake quality is improved, and the working efficiency of the auxiliary power unit is further improved. In addition, the application also relates to an auxiliary power unit.

Description

Technical Field

[0001] This invention belongs to the field of air intake and ventilation cooling for aircraft auxiliary power units, and relates to an air intake system for an auxiliary power unit, particularly an air intake system for an auxiliary power unit with a diverter. Furthermore, this invention also relates to an auxiliary power unit including such an air intake system. Background Technology

[0002] For example, the auxiliary power unit (APU) on commercial aircraft is mainly used to start the main engine, supply air to the aircraft's environmental control system in the air and on the ground, and power various onboard equipment. The APU's intake system and ventilation and cooling system both require airflow from the external environment. The intake system bleeds air to enable the normal operation of the APU's turbine unit, while the ventilation and cooling system bleeds air to cool the APU compartment and its accessories.

[0003] Currently, the typical APU (Air Processing Unit) intake system layout on commercial aircraft can be divided into two types: a separate layout, where the intake is separate from the ventilation and cooling system inlet, and an integrated layout, where the intake is integrated with the ventilation and cooling system inlet. In the separate layout, the opening of the APU intake system on the fuselage is far from the inlet of the ventilation and cooling system, allowing for independent air intake without interference. A typical schematic diagram of a separate intake and ventilation / cooling system inlet layout is shown below. Figure 1 As shown in the figure, in order to ensure the air intake and other needs of the ventilation and cooling system, additional openings, stamped fairings, and protective nets need to be added to the surface of the fuselage, which increases the complexity of the system and also increases the aircraft's flight drag.

[0004] In integrated layouts, the intake system and ventilation / cooling system share a single ram-type damper to capture the airflow, which is then distributed within a duct or air collection chamber. For example, a typical layout structure for an integrated arrangement is disclosed in US20100068036A1, filed by Hamilton Sundstrand Corp on September 15, 2008, entitled "Auxiliary power unit inlet duct with acoustic silencing." Figure 2 As shown in the figure, this arrangement is relatively simple in structure, but it is prone to uneven flow distribution and mutual interference between the air intakes of the two systems.

[0005] Furthermore, regardless of the arrangement described above, the air intake system is always located in the rear fuselage section of aircraft such as airplanes. At this location, the wall boundary layer is relatively thick, and the air intake ram air captures most of the low- to medium-energy fluid within the boundary layer, resulting in relatively poor work capacity and further affecting the APU's operating envelope.

[0006] Therefore, there is an urgent need to provide an improved intake system for an auxiliary power unit that can overcome one or more of the disadvantages of the prior art. Summary of the Invention

[0007] The purpose of this invention is to provide an air intake system for the intake and cooling of an auxiliary power unit. The air intake system is equipped with a baffle. On the one hand, the baffle can reduce the impact of the incoming boundary layer on the intake quality. On the other hand, by setting a baffle between the ram air intake and the surface of the aircraft body, the impact of the boundary layer on the intake quality can be reduced without increasing the external drag of the aircraft excessively.

[0008] According to one aspect of the present invention, an intake system for an auxiliary power unit is provided, the intake system of which may include:

[0009] Air intake flaps can be attached to the fuselage of an aircraft and can rotate between the open and closed positions;

[0010] The air intake duct can be located below the air intake damper to guide the air entering through the air intake damper to the air intake components of the auxiliary power unit.

[0011] A diverter can be installed along the fuselage of an aircraft in front of the air intake door, and can move between the open and closed positions of the diverter.

[0012] Cooling pipes, which can be installed below the partition, guide air entering through the partition to the cooling components of the auxiliary power unit; and

[0013] An actuating device may be attached to the intake damper and the duct to control the opening and closing of the intake damper and the duct.

[0014] This air intake system for the auxiliary power unit (APU) is an integrated arrangement that combines the intake system and the ventilation and cooling system inlet, and incorporates a baffle within the intake system. By using a baffle, the influence of the incoming boundary layer on the intake system can be effectively isolated, thereby improving intake quality and further enhancing APU efficiency. Furthermore, the baffle allows for sufficient cooling airflow to the ventilation and cooling system through its ramming effect, without interaction between the cooling airflow and the intake airflow of the intake device or system. Moreover, since the airflow rammed through the baffle flows into the ventilation and cooling duct, the airflow does not accumulate further upstream of the baffle, effectively reducing the impact of this arrangement on the aircraft's external drag.

[0015] According to the above aspects of the present invention, preferably, the diverter may include a first section, a second section at an angle to the first section, and a third section connecting the first and second sections, wherein, in the diverter closed position, the first section cooperates with the fuselage of the aircraft to form an aerodynamic surface, and in the diverter open position, an air intake gap is formed between the first section and the fuselage of the aircraft. Thus, in the diverter open position, boundary layer isolation and ram air intake for the ventilation and cooling system are achieved, while in the diverter closed position, the aircraft's drag can be reduced more effectively.

[0016] According to the above aspects of the invention, preferably, the diverter may further include a fourth section, which may have a wedge-shaped structure, wherein the diverter angle between the side of the wedge-shaped structure and the axis of symmetry of the diverter may be between 5 degrees and 30 degrees. With this arrangement, the incoming flow boundary layer can be diverted and pressurized to both sides of the wedge-shaped structure, thereby achieving the capture of the incoming flow by the ventilation and cooling system while ensuring intake air quality.

[0017] According to the above aspects of the invention, preferably, the fourth section divides the partition into a first guide passage and a second guide passage arranged side by side, and the cooling pipe includes a first cooling pipe and a second cooling pipe, wherein the first guide passage is in fluid communication with the first cooling pipe, and the second guide passage is in fluid communication with the second cooling pipe.

[0018] By setting up this fourth section, the incoming flow boundary layer is split to both sides and pressurized, thereby ensuring the intake air quality while enabling the ventilation and cooling system to capture the incoming flow.

[0019] According to the above aspects of the present invention, preferably, in order to further improve the intake quality, the cross-sectional area of ​​the first guide passage and the second guide passage can be gradually reduced from upstream to downstream along the flow path of the airflow.

[0020] According to the above aspects of the present invention, preferably, a smooth transition connection section can be formed between the fourth section and the second section, and the portion of the cooling pipe that mates with the diverter forms a fan-shaped structure. The diverter, constrained by its mating surface with the cooling pipe, can only reciprocate along a fixed direction. This arrangement allows for a sufficiently smooth airflow path while restricting the diverter's vertical movement to only up-and-down motion (i.e., movement approximately perpendicular to the fuselage surface), without any other degrees of freedom for relative motion.

[0021] According to the above aspects of the present invention, preferably, the intake damper can pivot between a damper open position and a damper closed position, while the diverter can linearly move between a diverter open position and a diverter closed position.

[0022] According to the above aspects of the present invention, preferably, the actuating device can be arranged such that the intake damper and the duct open or close synchronously, and the distance of linear movement of the duct corresponds to the angle of pivot movement of the intake damper. Thus, when the intake damper is in the open position and the closed position, the duct is correspondingly in the open position and the closed position, respectively. By synchronously opening or closing the intake damper and the duct, ram air intake of the ventilation and cooling system is achieved while isolating the influence of the incoming flow boundary layer.

[0023] According to the above aspects of the invention, preferably, the air intake damper and the diverter can be arranged adjacent to each other at the same opening on the aircraft fuselage, such that the air intake damper and the diverter completely close the opening in both the damper closed position and the diverter closed position. This integrated arrangement eliminates the need for additional openings, ram-furniture fairings, or protective nets on the fuselage surface, reducing system complexity and aircraft drag.

[0024] According to the above aspects of the present invention, preferably, the actuation device may include an actuator pivotally fixed to the fuselage of the aircraft and a push rod attached to the actuator, wherein the push rod is attached to the air intake damper at a first attachment portion and to the diverter at a second attachment portion.

[0025] The intake damper and the duct are synchronized by a push rod, which is highly efficient and reliable, and easy to install and maintain.

[0026] According to the above aspects of the invention, preferably, the duct may be provided with a through opening that allows a push rod to pass through so that the push rod is attached to the intake damper. Furthermore, a guide groove is provided in the through opening, and the second attachment portion is formed as a guide boss that engages with the guide groove to drive the push rod to move the duct. This arrangement achieves a stable and reliable guiding structure, enabling simultaneous control of the movement of the intake damper and the duct via the same push rod, while also resisting the ramming force of ram air together with associated components.

[0027] According to another aspect of the present invention, an auxiliary power device is proposed that includes an intake system comprising an auxiliary power device according to the above invention.

[0028] Therefore, the air intake system of the auxiliary power unit of the present invention can meet the usage requirements, overcome the shortcomings of the prior art, and achieve the intended purpose. Attached Figure Description

[0029] To further describe the intake system of the auxiliary power unit according to the present invention clearly, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, in which:

[0030] Figure 1 This is a schematic diagram showing the separate arrangement of the air intake system and the ventilation and cooling system inlet according to existing technology;

[0031] Figure 2 This is a schematic diagram of the integrated arrangement of the air intake system and ventilation and cooling system inlet according to existing technology;

[0032] Figure 3 This is a schematic diagram of the intake system of an auxiliary power unit according to a non-limiting embodiment of the present invention;

[0033] Figure 4 yes Figure 3 A schematic diagram of a portion of the intake system of the auxiliary power unit shown;

[0034] Figure 5 yes Figure 3 A schematic diagram of the intake system duct of the auxiliary power unit shown;

[0035] Figure 6 It is along Figure 5 A horizontal sectional view of the diaphragm taken from section AA in the diagram;

[0036] Figure 7 It is along Figure 5 The longitudinal sectional view of the duct taken from section BB in the middle;

[0037] Figure 8 yes Figure 3 A schematic diagram of the cooling pipes of the intake system of the auxiliary power unit shown;

[0038] Figure 9 yes Figure 3 A schematic diagram of the push rod of the actuation device of the intake system of the auxiliary power unit shown; and

[0039] Figure 10 This is a schematic diagram of the mechanism movement of the intake system of the auxiliary power unit according to a non-limiting embodiment of the present invention.

[0040] The above figures are for illustrative purposes only and are not drawn to scale.

[0041] The reference numerals in the figures are listed in the figures and embodiments:

[0042] 100 - The intake system of the auxiliary power unit includes:

[0043] 10 - Intake damper;

[0044] 20 - Air intake;

[0045] 30-Separation channel, including:

[0046] 30A - Part One;

[0047] 30B - Part Two;

[0048] 30C - Third Section;

[0049] 30D - Part 4;

[0050] 30E - Transition Connection Section;

[0051] 31 - First guiding pathway;

[0052] 32-Second guiding pathway;

[0053] 33 - Through opening, including:

[0054] 33A - Guide groove;

[0055] 40 - Cooling pipe, including:

[0056] 40A - Sector-shaped structure;

[0057] 41-First cooling pipe;

[0058] 42 - Second cooling pipe;

[0059] 50 - Actuating device, including:

[0060] 51-Actuator;

[0061] 52-Pushstick, including:

[0062] 52A - First Auxiliary Company;

[0063] 52B - Second Attached Unit;

[0064] A - Axis of symmetry;

[0065] α - Diverter angle. Detailed Implementation

[0066] It should be understood that, unless explicitly stated otherwise, the invention may employ various alternative orientations and sequences of steps. It should also be understood that the specific apparatus shown in the drawings and described in the specification are merely exemplary embodiments of the inventive concept disclosed and defined herein. Therefore, unless expressly stated otherwise, the specific orientations, directions, or other physical features involved in the various disclosed embodiments should not be considered limiting.

[0067] An auxiliary power unit (APU) is a small auxiliary power unit on an aircraft or flight vehicle that can independently output compressed air or electricity, in addition to the main propulsion system (engine). An APU may include an engine (such as a small gas turbine engine) and may include a power output shaft, compressed air extraction devices, and automatic control devices. Before takeoff, the APU provides compressed air to the aircraft, which can be used to supply air to the aircraft's air conditioning system or to provide an air source for starting the main engine's starter. It can also output electricity to the aircraft's electrical system before the main engine starts, reducing the aircraft's dependence on airport equipment. During flight, when the main engine or its power generation device fails, the APU can provide emergency energy to the aircraft, improving flight safety. During landing, the APU can provide energy to the aircraft. Currently, APUs are installed on large and medium-sized aircraft and large helicopters.

[0068] Typically, the Auxiliary Power Unit (APU) is housed within the tail cone at the rear of the aircraft fuselage. An air intake is located near the vertical stabilizer above the fuselage, and exhaust is discharged directly from the exhaust port at the rear of the tail cone. Both the APU's intake and cooling systems require airflow from the external environment. The intake system draws air to power the APU's gas turbine engine or turbine unit, while the cooling system draws air to cool the APU bay and its accessories.

[0069] Since the air intake of the air intake system is always located in the rear fuselage section of the aircraft, the boundary layer of the wall is relatively thick at this location. The air intake damper captures mostly low- to medium-energy fluids within the boundary layer, resulting in relatively poor work capacity and further affecting the APU's working envelope.

[0070] The present invention provides an air intake system for an auxiliary power device with a baffle. The air intake system uses a damper for ram air intake and a baffle that rises synchronously with the damper is set in front of the air intake. While isolating the influence of the incoming flow boundary layer, it realizes ram air intake for the ventilation and cooling system.

[0071] Figure 3 This is a schematic diagram of an air intake system 100 for an auxiliary power unit according to a non-limiting embodiment of the present invention, showing the state of the air intake system 100 when operating in the air, and illustrating the intake flow capture and flow process within each duct.

[0072] As shown in the figure and according to a non-limiting embodiment, the air intake system 100 of the auxiliary power unit may mainly include components such as an air intake damper 10, an air intake duct 20, a baffle 30, a cooling pipe 40, and an actuating device 50.

[0073] The air intake vent 10 can be attached to the fuselage 200 of the aircraft and can rotate between the vent open position and the vent closed position, for example, by pivoting via a mechanism such as a pivot hinge.

[0074] The intake duct 20 may be located below the intake damper 10, for example downstream of the intake airflow path, to guide the air entering through the intake damper 10 to the intake components of the auxiliary power unit 100, for example, to guide ram air to the turbine unit of the auxiliary power unit.

[0075] The structure of the air intake damper 10 and the air intake duct 20 themselves, and their attachment to the fuselage 200, are known in the art, and therefore will not be described in detail in this invention.

[0076] The diverter 30 can be positioned along the fuselage 200 in front of the air intake 10 (i.e., in front of the aircraft's flight direction or in the nose direction), and the diverter 30 is retractable, thus being able to move between the diverter open position and the diverter closed position, for example, linearly, particularly in a direction approximately perpendicular to the surface of the fuselage.

[0077] Figure 4 yes Figure 3 A schematic diagram of a portion of the intake system 100 of the auxiliary power unit shown; and Figure 5 yes Figure 3 A schematic diagram of the intake system 100 of the auxiliary power unit shown.

[0078] As shown in the figure, the diverter 30 may include a first section 30A, a second section 30B at an angle (e.g., approximately 90 degrees) to the first section 30A, and a third section 30C connecting the first section 30A and the second section 30B. The first section 30A and the second section 30B may be straight sections, while the third section 30C may be a curved section, thereby facilitating a smooth airflow transition from the upper surface of the diverter 30 to the intake duct 20.

[0079] In the closed position of the diverter 30, the first section 30A of the diverter 30 engages with the fuselage 200 of the aircraft to form an aerodynamic surface, such as a smooth and complete aerodynamic surface. Figure 3 As shown, the damper 10 and the baffle 30 are disposed adjacent to each other at the same opening 201 on the fuselage 200, so that in the damper closed position and the baffle closed position, the damper 10 and the baffle 30 can be engaged together to completely close the opening 201.

[0080] For example, when the front end (free end) of the damper 10 is closed, it presses against the rear end of the first section 30A or the front end of the third section 30C of the partition 30, so that the damper 10 and the partition 30 completely cover the opening 201, and the fuselage 200 has a smooth and complete aerodynamic surface at this point.

[0081] In the open position, an air intake gap is formed between the first section 30A of the diverter 30 and the fuselage 200 of the aircraft. By setting the diverter 30 between the ram air intake and the surface of the aircraft fuselage, the impact of the boundary layer on the air intake quality can be reduced without increasing the external drag of the aircraft excessively.

[0082] The terms “front,” “rear,” “front end,” and “rear end” used in this article are relative to the flight direction of the aircraft. That is, the direction of the aircraft’s nose or flight direction is “front” or “front end,” while the direction of the aircraft’s tail or the direction away from the flight direction is “rear” or “rear end.”

[0083] like Figure 4 and 5 As shown, the partition 30 may further include a fourth segment 30D, which serves as a spacer segment to divide the partition 30 into a first guide passage 31 and a second guide passage 32 arranged side by side. Preferably, the first guide passage 31 and the second guide passage 32 may be symmetrically shaped and arranged with respect to the fourth segment 30D.

[0084] Figure 6 It is along Figure 5 The horizontal sectional view of the diaphragm 30 cut by section AA; and Figure 7 It is along Figure 5 The longitudinal sectional view of the diaphragm 30 taken from section BB in the figure.

[0085] Combination Figure 4-6 As shown, the fourth segment 30D can be wedge-shaped, such that the cross-sectional area of ​​the first guide passage 31 and the second guide passage 32 can gradually decrease from upstream to downstream along the airflow path, for example... Figure 6 The curve decreases as shown in the diagram.

[0086] For example, a wedge structure with a certain angle is provided in the lower part of the diverter 30 (e.g., at the position of the fourth section 30D). The wedge structure includes two wedges arranged opposite each other and can split and pressurize the incoming flow boundary layer to both sides, thereby achieving the capture of the incoming flow by the ventilation and cooling system while ensuring the quality of the intake air.

[0087] like Figure 6 As shown, the side of the wedge structure (e.g., attached) Figure 6The angle α between the lower wedge surface shown in the diagram and the axis of symmetry A of the partition 30 (as shown by dashed lines) can be between 2 degrees and 50 degrees, preferably between 3 and 40 degrees, and even more preferably between 5 degrees and 30 degrees. Furthermore, preferably, the two wedge surfaces of the partition 30 can be arranged symmetrically, such that the two wedge surfaces (or the two sides, for example...) form a partition angle between the two wedge surfaces (or the two sides, for example...). Figure 6 The angle formed between the upper and lower sides shown in the figure is twice the channel angle α.

[0088] As a non-limiting example, a fan-shaped transition section 30E is formed between the fourth section 30D and the second section 30B. In this way, the upper surface of the diverter 30 transitions from a straight line to an arc shape along the incoming flow direction, thus smoothly transitioning with the inlet surface of the air intake.

[0089] like Figure 5 and 6 As shown in detail, the diverter 30 may be provided with a through opening 33, which may, for example, extend vertically through the outer surface of the fuselage 200 of the aircraft. The through opening 33 may be generally oblong, with its longitudinal axis extending in the flight direction, that is, in the front-to-back direction, for example, extending from the first segment 30A to the third segment 30C in the figure.

[0090] The through opening 33 allows the push rod 52 of the actuating device 50 to pass through so that the push rod 52 can be attached to the intake damper 10. The structure of the push rod 52 will be described in further detail below.

[0091] Figure 8 yes Figure 3 A schematic diagram of the cooling pipe 40 of the intake system 100 of the auxiliary power unit shown.

[0092] Combination Figure 3 , 4 As can be seen from Figures 8 and 9, the cooling pipe 40 can be positioned below the partition 30, for example, downstream of the cooling airflow path, to guide the air entering through the partition 30 to the cooling components of the auxiliary power unit 100, such as the cooling system that guides ram air to the APU.

[0093] It should be understood that the term "below" in this invention is used to describe an exemplary relative position between components, such as below or downstream along the air intake path, rather than to limit the absolute position between components. For example, depending on the aircraft's positioning and the arrangement of the air intake flaps and diverters on the aircraft fuselage, "below" may also be used to refer to "above" without departing from the scope of this invention.

[0094] As a non-limiting example, the cooling pipe 40 may include a first cooling pipe 41 and a second cooling pipe 42, which may be arranged symmetrically about the fourth segment 30D.

[0095] As shown in the figure, the first guide passage 31 of the partition 30 can be in fluid communication with the first cooling pipe 41, while the second guide passage 32 of the partition 30 can be in fluid communication with the second cooling pipe 42.

[0096] Preferably, the portion of the cooling pipe 40 that mates with the partition 30 also forms a fan-shaped structure 40A, so that the cooling pipe 40 can only move back and forth along the transition connection section 30E, i.e., a vertical movement, such as a vertical movement approximately perpendicular to the outer surface of the fuselage 200 of the aircraft.

[0097] The actuating device 50 can be simultaneously attached to the intake damper 10 and the duct 30 to control the opening and closing of the intake damper 10 and the duct 30.

[0098] In the embodiments disclosed herein, the actuation device 50 may include an actuator 51 and a push rod 52. The actuator 51 may be pivotally fixed to the fuselage 200 of the aircraft, and the actuator 51 may be any type of actuator or actuator known in the art, such as hydraulic or pneumatic actuator cylinders or actuators, as well as various electric actuators, etc.

[0099] The push rod 52 can be attached to the actuator 51 and actuated by the actuator 51 to extend or retract.

[0100] Figure 9 yes Figure 3 A schematic diagram of the push rod 52 of the actuation device 50 of the air intake system 100 of the auxiliary power unit shown.

[0101] As shown in the figure, the push rod 52 can be a straight bar-shaped structure, including a first attachment part 52A and a second attachment part 52B. The first attachment part 52A can be located at the end opposite to the actuator 51, while the second attachment part 52B can be arranged at approximately the middle position of the push rod 52.

[0102] The push rod 52 can be made of any metal or non-metal composite material, but preferably, the push rod 52 has sufficient rigidity to withstand the corresponding pivoting force and the force of the ram air without significant bending or deformation.

[0103] like Figure 3 As shown, push rod 52 can be attached to intake damper 10 at first attachment portion 52A, and push rod 52 can be attached to diverter 30 at second attachment portion 52B. This arrangement allows the opening angle of intake damper 10 to be greater than the opening angle of diverter 30 during the movement of the same push rod 52.

[0104] The through opening 33 of the duct 30 allows the push rod 52 to pass through, so that the push rod 52 can be attached to the intake damper 10. Additionally, as... Figure 7 As shown in detail, a guide groove 33A is provided in the through opening 33. The guide groove 33A can be a straight groove and can be arranged laterally on the side wall of the through opening 33. Correspondingly, the second attachment part 52B can be formed as a guide boss, which can be cylindrical, so as to cooperate with the guide groove 33A to drive the push rod 52 to move the partition 30, thereby realizing the lifting control of the partition 30.

[0105] The actuating device 50 can be arranged so that the intake damper 10 and the duct 30 open or close synchronously. Thus, when the intake damper 10 is in the open position and the closed position, the duct 30 is correspondingly in the open position and the closed position, respectively. In this way, the upward opening height of the duct 30 can correspond to the pivoting angle of the intake damper 10, thereby ensuring sufficient incoming airflow through the duct 30 into the cooling pipe 40.

[0106] Figure 10 This is a schematic diagram of the mechanism movement of the air intake system 100 of the auxiliary power unit according to a non-limiting embodiment of the present invention.

[0107] Figure 10 The various components of the intake system 100 have been simplified to illustrate their movement. As shown, the intake damper 10 is simplified to a horizontal bar, and the actuator 51 is simplified to a slider, both of which can rotate around a fixed hinge. Additionally, the cooling pipe 40 is simplified to a fixed slider. The lifting baffle 30 can move up and down relative to the cooling pipe 40 while simultaneously guiding the cylindrical boss (i.e., the second attachment 52B) on the push rod 52 to move linearly via the guide groove 33A. Therefore, the baffle 30 can be simplified to a straight rod and a square slide groove fixedly connected together (as shown in the figure). The guide groove 33A can be used to constrain the boss on the push rod 2 (the solid black circle in the figure), while the straight rod moves up and down along the fixed slider (cooling pipe 40).

[0108] In the diagram, solid lines indicate that the intake damper 10 is in the closed position (or closed state), while dashed lines indicate that the intake damper 10 is in the open position (or open state). The movement from the closed position to the open position can be described, for example, as follows: under the action of actuator 51, push rod 52 gradually extends, causing intake damper 10 to rotate around the hinge. At the same time, the second attachment part 52B (in the form of a boss) also rises with push rod 52, thereby causing the lifting partition 30 to move upward. During this process, the second attachment part 52B slides to the left relative to the guide groove 33A (or slide groove) of lifting partition 30, thereby opening intake damper 10 and partition 30. The reverse of the above process is the movement path of intake damper 10 and partition 30 closing.

[0109] It can be seen that the intake system of the present invention can simultaneously achieve the corresponding rise of the duct 30 when the intake damper 10 is opened, thereby optimizing the intake quality and achieving ram capture of the cooling airflow.

[0110] The terms “front,” “upstream,” and “downstream,” etc., used herein to indicate orientation or direction, and the terms “first,” “second,” etc., used to indicate sequence, are merely to enable those skilled in the art to better understand the concept of the invention as illustrated in preferred embodiments, and are not intended to limit the invention. Unless otherwise stated, all sequences, orientations, or directions are used only to distinguish one element / component / structure from another, and unless otherwise stated, do not indicate any particular order, sequence of operations, direction, or orientation. For example, in an alternative embodiment, “first cooling pipe” may be “second cooling pipe,” and “first guide passage” may alternatively refer to “second guide passage.”

[0111] In summary, the air intake system 100 of the auxiliary power unit according to the embodiments of the present invention overcomes the shortcomings of the prior art and achieves the intended purpose of the invention.

[0112] While the intake system of the auxiliary power unit of the present invention has been described above with reference to preferred embodiments, those skilled in the art should recognize that the above examples are merely illustrative and should not be construed as limiting the invention. Therefore, various modifications and variations can be made to the invention within the spirit and scope of the claims, and all such modifications and variations will fall within the scope claimed by the claims.

Claims

1. An air intake system (100) for an auxiliary power unit, characterized in that, The intake system includes: Air intake flap (10), which is attached to the fuselage (200) of the aircraft and is rotatable between an open position and a closed position; An air intake duct (20) is provided below the air intake damper (10) to guide air entering through the air intake damper (10) to the air intake component of the auxiliary power unit; A diverter (30) is provided along the fuselage (200) of the aircraft in front of the air intake door (10) and is movable between an open position and a closed position; A cooling pipe (40) disposed below the partition (30) to guide air entering via the partition (30) to the cooling components of the auxiliary power unit; and An actuating device (50) is attached to the intake damper (10) and the partition (30) to control the opening and closing of the intake damper (10) and the partition (30). The partition (30) includes a first section (30A), a second section (30B) at an angle to the first section (30A), and a third section (30C) connecting the first section (30A) and the second section (30B). In the closed position of the partition, the first section (30A) cooperates with the fuselage (200) of the aircraft to form an aerodynamic surface, while in the open position of the partition, an air intake gap is formed between the first section (30A) and the fuselage (200) of the aircraft.

2. The intake system (100) of the auxiliary power unit according to claim 1, characterized in that, The partition (30) also includes a fourth section (30D) having a wedge-shaped structure, wherein the partition angle (α) between the side of the wedge-shaped structure and the axis of symmetry (A) of the partition (30) is between 5 degrees and 30 degrees.

3. The intake system (100) of the auxiliary power unit according to claim 2, characterized in that, The fourth section (30D) divides the partition (30) into a first guide passage (31) and a second guide passage (32) arranged symmetrically side by side, and the cooling pipe (40) includes a first cooling pipe (41) and a second cooling pipe (42), wherein the first guide passage (31) is in fluid communication with the first cooling pipe (41), and the second guide passage (32) is in fluid communication with the second cooling pipe (42).

4. The intake system (100) of the auxiliary power unit according to claim 3, characterized in that, The cross-sectional areas of the first guide passage (31) and the second guide passage (32) gradually decrease from upstream to downstream along the flow path of the airflow.

5. The intake system (100) of the auxiliary power unit according to claim 4, characterized in that, A smooth transition connection section (30E) is formed between the fourth section (30D) and the second section (30B), and the part of the cooling pipe (40) that mates with the partition (30) forms a fan-shaped structure (40A). The partition (30) is constrained by the mating surface between the partition and the cooling pipe (40) and can only reciprocate in a fixed direction.

6. The intake system (100) of the auxiliary power unit according to any one of claims 1-5, characterized in that, The air intake damper (10) pivots between the damper open position and the damper closed position.

7. The intake system (100) of the auxiliary power unit according to claim 6, characterized in that, The partition (30) moves linearly between the partition open position and the partition closed position.

8. The intake system (100) of the auxiliary power unit according to claim 7, characterized in that, The actuating device (50) is arranged such that the air intake damper (10) and the partition (30) open or close synchronously, and the distance of linear movement of the partition (30) corresponds to the angle of pivot movement of the air intake damper (10).

9. The intake system (100) of the auxiliary power unit according to claim 8, characterized in that, The actuation device (50) includes an actuator (51) pivotally fixed to the fuselage of the aircraft and a push rod (52) attached to the actuator (51), wherein the push rod (52) is attached to the air intake vent (10) at a first attachment (52A) and the push rod (52) is attached to the diverter (30) at a second attachment (52B).

10. The intake system (100) of the auxiliary power unit according to claim 9, characterized in that, The partition (30) is provided with a through opening (33) through which the push rod (52) passes to attach the push rod (52) to the air intake damper (10). A guide groove (33A) is provided in the through opening (33), and the second attachment part (52B) is formed as a guide boss. The guide boss cooperates with the guide groove (33A) to drive the partition (30) to move.

11. An auxiliary power unit comprising an intake system (100) of an auxiliary power unit according to any one of claims 1-10.

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