Unmanned aerial vehicle and air inlet channel anti-icing grating system thereof

Abstract

The invention discloses an unmanned aerial vehicle and an air inlet channel anti-icing grating system thereof, and relates to the technical field of aircrafts, the air inlet channel anti-icing grating system comprises a grating body arranged along an air inlet channel, the two ends of the grating body are connected with the air inlet channel in a sealed mode, and the periphery of the grating body is provided with a heat preservation channel used for maintaining the surface temperature of the grating. A plurality of grilles are arranged in the grille body, air entraining channels communicated with the heat preservation channels are arranged in the grilles so that the heat preservation channels and the air entraining channels can form heat medium flowing channels, an air inlet is formed in one end of each heat medium flowing channel, and an exhaust port is formed in the other end of each heat medium flowing channel. The anti-icing grating is arranged on the air inlet channel along the way, so that anti-icing on the surface of the grating and ice melting on the main flow of the air inlet channel are realized, the particle size and the mass of ice particles are effectively reduced, and the ice particles separated from the lip of the air inlet channel are prevented from impacting and damaging blades of an engine.

Description

Technical Field

[0001] This invention relates to the field of aircraft technology, and more specifically, to an air intake anti-icing grid system. Furthermore, this invention also provides a drone including the aforementioned air intake anti-icing grid system. Background Technology

[0002] Under complex weather conditions, drones face serious safety risks when conducting cloud precipitation detection and catalysis operations. When the cloud contains a large number of supercooled water droplets with a temperature below 0°C, the windward surface of the drone, especially the air intake lip, wing surface and sensor probe, is prone to water condensation and ice formation.

[0003] As a core aerodynamic component of the engine, the air intake duct becomes a critical component. When ice forms on the intake lip, it covers the surface of the lip, disrupting the airflow boundary layer, prematurely inducing airflow separation, creating vortices and turbulence, and increasing compressor surface distortion. Simultaneously, the ice reduces the inlet area, decreases the intake air mass and flow rate, leading to a decrease in engine thrust. If icing worsens, further reduction in intake airflow may cause compressor surge, and in severe cases, engine shutdown.

[0004] Currently, air intake anti-icing mainly focuses on hot air anti-icing and electric heating anti-icing at the lip, without considering that ice particles falling off the lip can be sucked into the core components of the engine. High-speed impacting ice particles may damage engine blades, leading to a decrease in engine aerodynamic performance or even blade breakage, directly affecting the flight safety of UAVs.

[0005] In summary, how to prevent ice particles falling from the intake lip from damaging engine blades is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide an air intake anti-icing grille system, which provides an anti-icing grille along the air intake, thereby achieving anti-icing of the grille surface and melting of the main flow of the air intake, effectively reducing the particle size and mass of ice particles, and preventing ice particles detaching from the air intake lip from impacting and damaging the engine blades.

[0007] The present invention also provides a drone including the above-mentioned air intake anti-icing grid system, which is suitable for operation in icing environments, especially in cold and humid environments.

[0008] To achieve the above objectives, the present invention provides the following technical solution:

[0009] An air intake anti-icing grille system includes a grille body disposed along the air intake, with both ends of the grille body being sealed to the air intake. The outer periphery of the grille body is provided with a heat-insulating channel for maintaining the surface temperature of the grille. The grille body contains a plurality of grilles, and the grilles contain an air-drawing channel communicating with the heat-insulating channel, so that the heat-insulating channel and the air-drawing channel constitute a heat medium flow channel. One end of the heat medium flow channel is provided with an air inlet, and the other end of the heat medium flow channel is provided with an exhaust port.

[0010] Preferably, the heat insulation channel is arranged around the outer periphery of the grille body, and the heat insulation channel has an axial extension of the grille body;

[0011] The heat preservation channel includes an air intake area and an air exhaust area, which are separated by a partition. The air intake area is connected to the air inlet and the inlet of the air intake channel, and the air exhaust area is connected to the outlet of the air intake channel and the exhaust port.

[0012] Preferably, the grille extends axially along the mainstream airflow direction of the air intake duct, and the grille is vertically arranged at equal intervals along the cross-section of the grille body.

[0013] Preferably, the two ends of the heat medium flow channel are respectively provided with an air inlet chamber and an air outlet chamber, the air inlet is located at the end of the air inlet chamber that is relatively far away from the air intake channel, and the air outlet is located at the end of the air outlet chamber that is relatively far away from the air intake channel.

[0014] Preferably, the two ends of the grille body are detachably provided with connecting clamps for connecting with the air intake, and a sealing ring is provided between the grille connecting end of the connecting clamp and the end face of the grille body.

[0015] Preferably, the outer periphery of the grid body is provided with a plurality of protruding connecting parts, the connecting parts are provided with mounting holes for installing fastening bolts, the mounting holes are not connected to the insulation channel, and the fastening bolt passes through the connecting hole of the connecting clamp, the sealing ring, the mounting hole, the sealing ring at the other end and the connecting hole of the connecting clamp at the other end in sequence before being connected to the fastening nut.

[0016] Preferably, it also includes a lock nut, which is provided on the side of the fastening nut that is relatively away from the connecting clamp, and the lock nut is threadedly connected to the fastening bolt.

[0017] Preferably, the windward surface of the grille body is perpendicular to the direction of the mainstream airflow in the air intake, so as to reduce the impact aerodynamic loss of the mainstream.

[0018] Preferably, the flow area of ​​the heat preservation channel and the flow area of ​​the air intake channel are both smaller than the cross-sectional area of ​​the air inlet.

[0019] An unmanned aerial vehicle (UAV) includes the air intake anti-icing grille system described in any of the preceding claims.

[0020] The intake duct anti-icing grille system provided by this invention features an anti-icing grille along the intake duct. The grille inside the main body can break detached ice particles into smaller ice particles, reducing the impact damage to the engine blades. At the same time, a high-pressure air source flows in the insulation channel and the bleed air channel to heat the main flow of the intake duct, achieving anti-icing on the grille surface and melting of the main flow. This further reduces the particle size and mass of the ice particles, preventing ice particles from detaching from the intake duct lip and impacting and damaging the engine blades. It is suitable for engine operation in icing environments, especially in cold and humid environments.

[0021] In addition, the present invention also provides a drone including the above-described air intake anti-icing grille system. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 This is an assembly diagram of the air intake anti-icing grille system provided by the present invention.

[0024] Figure 2 This is a schematic diagram showing the installation position of the grille body along the air intake duct.

[0025] Figure 3 An exploded schematic diagram of an air intake anti-icing grille system;

[0026] Figure 4 A cross-sectional view of an anti-icing grille;

[0027] Figure 5 This is a side view of an anti-icing grille.

[0028] Figures 1-5 middle:

[0029] 10-Intake duct; 101-Lip; 20-Anti-icing grille; 1-Grill body; 11-Intake chamber; 111-Intake port; 12-Insulation channel; 121-Partition; 13-Grill; 131-Air duct; 14-Exhaust chamber; 141-Exhaust port; 15-Connecting flange; 151-Mounting hole; 16-Connecting part; 2-Sealing ring; 3-Connecting clamp. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] The core of this invention is to provide an air intake anti-icing grille system, in which an anti-icing grille is provided along the air intake, achieving anti-icing of the grille surface and melting of the main flow of the air intake, effectively reducing the particle size and mass of ice particles, and preventing ice particles detaching from the air intake lip from impacting and damaging the engine blades.

[0032] The present invention also provides a drone including the above-mentioned air intake anti-icing grid system, which is suitable for operation in icing environments, especially in cold and humid environments.

[0033] The air intake anti-icing grille system provided by the present invention includes a grille body 1 disposed along the air intake 10. The two ends of the grille body 1 are respectively sealed and connected to the air intake 10. The outer periphery of the grille body 1 is provided with a heat insulation channel 12 for maintaining the surface temperature of the grille. The grille body 1 is provided with a plurality of grilles 13 inside. The grilles 13 are provided with an air intake channel 131 communicating with the heat insulation channel 12, so that the heat insulation channel 12 and the air intake channel 131 constitute a hot medium flow channel. One end of the hot medium flow channel is provided with an air inlet 111, and the other end of the hot medium flow channel is provided with an exhaust port 141.

[0034] Please refer to Figure 1 The two ends of the grille body 1 are respectively sealed to the air intake 10. The grille body 1 can be sealed to the air intake 10 by welding or by detachable means such as flange connection, so as to facilitate the maintenance and replacement of the grille body 1.

[0035] The main body of the grille 1 is located along the air intake 10 to prevent ice particles falling off the lip 101 from being sucked in and impacting and damaging the engine blades. Therefore, the main body of the grille 1 is located downstream of the lip 101 along the mainstream airflow direction of the air intake 10. The specific position of the main body of the grille 1 along the air intake 10 and the tilt angle of the main body of the grille 1 need to be determined by actual tests or numerical simulations based on the design status of the aircraft and the velocity vector distribution inside the air intake 10, so as to meet the anti-icing and de-icing requirements while minimizing the aerodynamic losses caused by the grille 13.

[0036] The grille body 1 is typically located at the rear section of the air intake duct 10. The grille body 1 extends approximately 70%-80% of the way along the centerline of the air intake duct from the inlet to the installation position, and the angle between the grille body 1 and the tangent to the centerline of the air intake duct is controlled to be 88°-92°. Figure 2 As shown, this is to simultaneously meet the anti-icing requirements as well as engine performance requirements such as total pressure recovery coefficient and circumferential total pressure distortion index.

[0037] For preferred options, please refer to [the following]. Figure 2 The windward side of the grille body 1 is perpendicular to the mainstream airflow direction of the intake duct 10 to reduce the impact aerodynamic loss of the mainstream airflow. In addition, the mainstream airflow can also be used to assist in anti-icing.

[0038] The outer periphery of the grille body 1 is provided with a heat insulation channel 12, which is connected to the air intake channel 131 of the grille 13 so that the heat medium flows through the heat insulation channel 12 to heat the inner and outer surfaces of the grille body 1. On the one hand, it can maintain the surface temperature of the anti-icing grille 20 above 0°C and prevent supercooled water droplets from condensing and freezing on the grille surface. On the other hand, the heat insulation channel 12 can transfer heat to the inner cavity of the grille through the inner wall, and work with the air intake channel 131 of the grille 13 to quickly and fully exchange heat with the main flow of the air intake, thereby melting the ice particles carried in the main flow of the air intake, reducing the particle size of the ice particles or even melting them completely.

[0039] Preferably, the heat insulation channel 12 can be arranged around the outer periphery of the grille body 1. Therefore, the heat insulation channel 12 is an annular channel, which is simple in structure and easy to process compared to several non-connected arc-shaped channels. The heat insulation channel 12 extends axially from the grille body 1, which helps to improve the uniformity of the grille surface temperature in the axial direction.

[0040] At this time, the heat medium can form two different flow paths: "inlet 111-insulation channel 12-exhaust channel 131-insulation channel 12-exhaust port 141" and "inlet 111-insulation channel 131-exhaust port 141", so that the heat medium can fully exchange heat with the mainstream of the intake channel.

[0041] Preferably, the heat insulation channel 12 can be provided with an air intake area and an exhaust area, which are separated by a partition 121. The air intake area is connected to the air inlet 111 and the inlet of the air intake channel 131, and the exhaust area is connected to the outlet of the air intake channel 131 and the exhaust port 141. The partition 121 can prevent the hot medium from flowing out directly through the heat insulation channel 12 without flowing through the air intake channel 131, and ensure that the hot medium in the air intake channel 131 can fully exchange heat with the main flow of the air intake channel in the center of the inner cavity.

[0042] The main body of the grille 1 has several grilles 13 inside. The grilles 13 can break ice particles into smaller ice particles through collision, thereby reducing the impact of ice particles on the engine blades by reducing the particle size. In order to ensure that the grilles 13 can withstand the impact of high-speed, large-diameter ice particles and avoid impact damage to the grilles 13, the main body of the grille 1 needs to be processed and manufactured using high-strength materials, such as high-strength titanium alloys like TC4-ELI material (Ti-6Al-4V EL, ultra-low gap element α+β type titanium alloy), ultra-high-strength aluminum alloys, and fiber-reinforced composite materials.

[0043] The number, configuration, and distribution of grilles 13 not only determine the effect of grilles 13 on ice particles, but also affect the contact area between grilles 13 and the main flow of the intake, thus affecting the aerodynamic performance of the main flow of the intake. If the spacing of grilles 13 is too large, it will not be able to effectively block ice particles with smaller diameters. If the spacing of grilles 13 is too small, it will increase the aerodynamic loss of the main flow of the intake and block the airflow.

[0044] The spacing of the grille 13 must ensure that ice particles of typical diameter under the aircraft's operating conditions, such as ice particles with a diameter of 40mm, can be broken by collision. The specific spacing of the grille 13 needs to be determined by design calculations based on the range of ice particle size under the aircraft's operating conditions and the aerodynamic performance requirements of the engine, and then iteratively optimized through numerical simulation and other methods.

[0045] To reduce flow loss caused by the grille 13, preferably, the grille 13 can be arranged to extend axially along the mainstream airflow direction of the intake duct 10, and the grille 13 can be arranged vertically at equal intervals along the cross-section of the grille body 1, such as... Figure 3 As shown.

[0046] The grille 13 is provided with an air intake channel 131, which is used to heat the grille cavity separated by the grille 13. By increasing the surface temperature of the grille 13, the mainstream of the intake duct is heated and melted. The flow area of ​​the air intake channel 131 will affect the flow rate of the heat medium, thereby affecting the heat exchange efficiency between the grille 13 and the mainstream of the intake duct. In addition, it will also affect the structural strength and impact resistance of the grille 13.

[0047] Therefore, the dimensions of the air intake channel 131 inside the grille 13 need to take into account both structural strength and the design flow requirements of the heat medium. The spacing of the grille 13 and the dimensions of the air intake channel 131 are used as design variables for iterative optimization in order to determine the configuration of the grille body 1.

[0048] For example, in one specific embodiment, the porosity of the grid body 1 is 0.8-0.9 in order to optimize the airflow uniformity at the outlet section of the grid body 1 and reduce the risk of boundary layer separation.

[0049] The heat insulation channel 12 and the air intake channel 131 constitute the heat medium flow channel of the grille body 1. It should be noted that the heat medium here is usually the high temperature and high pressure gas from the engine outlet. Compared with the high temperature circulating water of the heat dissipation system, the gas source temperature of the high temperature and high pressure gas can reach 170-220℃ and the gas source pressure can reach 0.2-0.3MPa. It has higher heat transfer efficiency and energy density, and its heat exchange capacity is significantly better than that of high temperature circulating water.

[0050] One end of the heat medium flow channel is provided with an air inlet 111, which is connected to the heat medium source through an air intake pipe. For example, the air inlet 111 is connected to the engine, which is a high-pressure air source. The other end of the heat medium flow channel is provided with an exhaust port 141, which is connected to the external environment through an exhaust pipe. The air inlet 111 and the air intake pipe, and the exhaust port 141 and the exhaust pipe can be connected by detachable connection methods such as threaded connection or quick-release coupling connection, so as to facilitate the inspection, maintenance and replacement of the grille body 1.

[0051] The aforementioned air inlet 111 and exhaust outlet 141 can be connected to the outer periphery of the grille body 1 by a detachable connection, or they can be welded to the outer periphery of the grille body 1, or the air inlet and exhaust outlet can be integrated with the grille body 1.

[0052] In this embodiment, an anti-icing grille 20 is provided along the intake duct 10. The grille 13 inside the grille body 1 can break the falling ice particles into small ice particles, reducing the impact damage to the engine blades. At the same time, the high-pressure air source flows in the insulation channel 12 and the bleed air channel 131 to heat the main flow of the intake duct, realizing anti-icing of the grille surface and melting of the main flow, further reducing the particle size and mass of the ice particles, and preventing the lip 101 of the intake duct 10 from detaching from the ice particles and damaging the engine blades. It is suitable for the engine to operate in icing environments, especially in cold and humid environments.

[0053] Preferably, the flow area of ​​the heat insulation channel 12 and the flow area of ​​the air intake channel 131 can be set to be smaller than the cross-sectional area of ​​the air inlet 111, so as to increase the flow velocity of the heat medium by reducing the flow area, thereby improving the wetted area of ​​the heat medium and the heat exchange efficiency.

[0054] Please refer to Figure 4 and Figure 5 The two ends of the hot medium flow channel are respectively provided with an air inlet chamber 11 and an exhaust chamber 14. The air inlet 111 is located at the end of the air inlet chamber 11 that is relatively far away from the air intake channel 131, and the exhaust port 141 is located at the end of the exhaust chamber 14 that is relatively far away from the air intake channel 131.

[0055] Compared to the direct connection between the inlet and outlet ports and the external insulation channel 12, the arrangement of the inlet and outlet ports not only facilitates the processing of the inlet and outlet ports, but also makes it easier to set the flow channel area of ​​the insulation channel 12 and the flow channel area of ​​the air intake channel 131 to be smaller than the cross-sectional area of ​​the air inlet 111.

[0056] Based on the above embodiments, the connection method between the grille body 1 and the air intake 10 is defined. Both ends of the grille body 1 are detachably provided with connecting clamps 3 for connecting with the air intake 10. A sealing ring 2 is provided between the grille connection end of the connecting clamp 3 and the end face of the grille body 1.

[0057] The connecting clamp 3 and the air intake duct 10 are detachably connected, and the two can be connected using common connecting parts such as fastening bolts and connecting pins; please refer to [reference needed]. Figure 3 The connecting clamp 3 is fixed to the air intake 10, and the grille connecting end is bolted to the connecting flange 15 of the grille body 1.

[0058] To prevent leakage of the hot medium from the gap between the connecting clamp 3 and the connecting flange 15, a sealing ring 2 is provided between the connecting clamp 3 and the connecting flange 15. Considering that the sealing ring 2 may come into contact with the hot medium, the sealing ring 2 should have good high-temperature performance to ensure the sealing performance of the sealing ring 2 and extend its service life.

[0059] In this embodiment, the grille body 1 is detachably connected to the air intake 10 via a connecting clamp 3, and a sealing ring 2 is provided between the two, which ensures both the sealed connection between the grille body 1 and the air intake 10 and the maintainability of the grille body 1.

[0060] Preferably, in order to better support the connecting flanges 15 at both ends of the grille body 1, the outer periphery of the grille body 1 is provided with several protruding connecting parts 16. The connecting parts 16 are provided with mounting holes for installing fastening bolts. The mounting holes are not connected to the insulation channel 12. The fastening bolts pass through the connecting hole of the connecting clamp 3, the sealing ring 2, the mounting hole, the sealing ring 2 at the other end, and the connecting hole of the connecting clamp 3 at the other end in sequence, and are then connected to the fastening nut. The connection structure is simple and has strong connection strength and reliability.

[0061] To prevent the fastening bolts connecting the grille body 1 and the air intake 10 from loosening, the above-mentioned threaded connection structure is provided with an anti-loosening structure. This can be achieved by providing an anti-loosening nut, with the anti-loosening nut located on the side of the fastening nut that is relatively far from the connecting clamp 3. The anti-loosening nut is threadedly connected to the fastening bolt. The anti-loosening nut can be set as a regular nut, a slotted nut, or a mechanical anti-loosening nut, etc. Alternatively, the fastening nut can be directly set as a slotted nut or a mechanical anti-loosening nut.

[0062] In addition to the aforementioned air intake anti-icing grille system, the present invention also provides a drone that includes the air intake anti-icing grille system disclosed in the above embodiments. The structure of other parts of the drone can be referred to the prior art, and will not be described in detail here.

[0063] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0064] The above provides a detailed description of the UAV and its air intake anti-icing grille system provided by this invention. Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the embodiments above are merely for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make various improvements and modifications to this invention without departing from its principles, and these improvements and modifications also fall within the protection scope of the claims of this invention.

Claims

1. An air intake anti-icing grid system, comprising: The application relates to an air inlet channel anti-icing grille system, which comprises a grille body (1) arranged along an air inlet channel (10), the two ends of the grille body (1) are in sealing connection with the air inlet channel (10), the outer peripheral part of the grille body (1) is provided with a heat preservation channel (12) for maintaining the temperature of the grille surface, a plurality of grilles (13) are arranged in the grille body (1), the grilles (13) are internally provided with air guide channels (131) in communication with the heat preservation channel (12), so that the heat preservation channel (12) and the air guide channel (131) form a heat medium flow channel, one end of the heat medium flow channel is provided with an air inlet (111), and the other end of the heat medium flow channel is provided with an air outlet (141).

2. The air intake anti-icing grid system of claim 1, wherein, The heat preservation channel (12) is arranged around the outer peripheral part of the grille body (1), and the heat preservation channel (12) has an axial extension of the grille body (1); The heat preservation channel (12) comprises an air inlet area and an air outlet area, the air inlet area and the air outlet area are separated by a partition (121), the air inlet area is in communication with the air inlet (111) and the inlet of the air guide channel (131), and the air outlet area is in communication with the outlet of the air guide channel (131) and the air outlet (141).

3. The inlet duct ice protection grid system of claim 1, wherein, The grilles (13) are arranged in an axial extension along the main airflow direction of the air inlet channel (10), and the grilles (13) are vertically arranged at equal intervals along the cross section of the grille body (1).

4. The inlet duct ice protection grid system of claim 1, wherein, The two ends of the heat medium flow channel are respectively provided with an air inlet cavity (11) and an air outlet cavity (14), the air inlet (111) is arranged at one end of the air inlet cavity (11) which is relatively far away from the air guide channel (131), and the air outlet (141) is arranged at one end of the air outlet cavity (14) which is relatively far away from the air guide channel (131).

5. The inlet duct ice protection grid system of claim 1, wherein, The two ends of the grille body (1) are detachably provided with connecting clamps (3) for connecting with the air inlet channel (10), and a sealing ring (2) is arranged between the grille connecting end of the connecting clamp (3) and the end face of the grille body (1).

6. The air intake anti-icing grid system of claim 5, wherein, The outer peripheral part of the grille body (1) is provided with a plurality of protruding connecting parts (16), the connecting parts (16) are provided with mounting holes (151) for mounting fastening bolts, the mounting holes (151) are not in communication with the heat preservation channel (12), the fastening bolts pass through the connecting holes of the connecting clamps (3), the sealing rings (2), the mounting holes (151), the sealing rings (2) at the other ends and the connecting holes of the connecting clamps (3) at the other ends in sequence and are connected with fastening nuts.

7. The air intake anti-icing grid system of claim 6, wherein, The fastening nuts are provided with anti-loosening nuts on the sides which are relatively far away from the connecting clamps (3), and the anti-loosening nuts are in threaded connection with the fastening bolts.

8. The air intake anti-icing grid system of any one of claims 1-7, wherein, The windward face of the grille body (1) is perpendicular to the main airflow direction of the air inlet channel (10), so as to reduce the impact aerodynamic loss of the main flow.

9. The air intake anti-icing grid system of any one of claims 1-7, wherein, The flow channel area of the heat preservation channel (12) and the flow channel area of the air guide channel (131) are both smaller than the sectional area of the air inlet (111).

10. A drone, characterized in that, The application further relates to an air inlet channel anti-icing grille system according to any one of claims 1-9.

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