Hail production equipment and hail preparation method

Abstract

The invention relates to hail production equipment and a hail preparation method. The hail production equipment comprises a hail solidification device, a cold air supply device, a steam supply device, a driving mechanism and an airflow enhancement mechanism. The hail solidification device comprises a fixed seat and a rotating tank rotatably arranged on the fixed seat, and the rotating tank is provided with an ice making cavity. The cold air supply device is used for introducing cold air into the ice-making cavity, and the steam supply device is used for introducing water steam into the ice-making cavity. The driving mechanism drives the rotating tank to rotate. The airflow increasing mechanism is connected with the hail solidification device and used for introducing lifting airflow from bottom to top into the ice making cavity. According to the hail production equipment provided by the invention, the hail production process is furthest close to the hail generation process in the natural world in the hail production process, the simulated hail which is irregular in shape and extremely close to the real hail in density and hardness can be prepared, and a more reliable test material is provided for an aircraft hail impact resistance test; the method improves the accuracy and reliability of test data, and is of great significance to aircraft structure safety evaluation.

Description

Technical Field

[0001] This invention relates to the field of electromechanical technology, and in particular to a hail production equipment and a hail preparation method. Background Technology

[0002] Thin-walled structures are widely used in the structural design of civil aircraft. Laminated composite materials have been widely used in aircraft due to their excellent mechanical properties. However, composite materials have poor resistance to out-of-plane impacts and are prone to delamination after impact, leading to a decrease in in-plane load-bearing capacity. Commercial aircraft operate in all weather conditions, and hail impact resistance is one of the important driving loads in aircraft fuselage design. Hail impacts on aircraft can be low-speed impacts at ground level and high-speed impacts during cruise. The former is often unavoidable, and aircraft design typically uses post-impact compression allowable values ​​as design inputs. If impact tests are conservative, the aircraft will bear a significant additional weight during operation. In the atmospheric environment, hail conditions are always unpredictable and uncontrollable. Therefore, how to accurately simulate the impact of hail impacts on aircraft structures has always been a focus of mechanical test design. The effectiveness of hail preparation and simulation has a significant impact on the accurate simulation of the impact of hail impacts on aircraft structures in mechanical tests.

[0003] There are roughly three existing methods for preparing hailstones. One method involves injecting water into a spherical mold and freezing it to obtain ice balls. For example, patents such as "201610021326.1 / Ice-making mold and manufacturing method for hailstones used in aircraft engine ice ingestion test", "201810395421.7 / A hail test device and hail test method", and "202210904698.4 / An ice ball unlocking fixture and ice ball making device for hail testing" all involve injecting water into a spherical mold and freezing it. Another method involves mixing carbon dioxide or cotton wool into the water to adjust the volume and density of the hailstones, thus regulating the ice ball formation characteristics. Examples include patents such as "US10119739B2 / HAIL PRODUCING MACHINE" and "ASTM F320 Standard test method for hail impact resistance of aerospace transparent enclosures". The second method for preparing hail involves crushing ice into small pieces, then extruding and solidifying them with water vapor to form spherical hailstones of variable density, as described in the prior art patent "202210904698.4 / An ice ball unlocking fixture and ice ball making device for hail testing". The third method involves mixing water and carbon dioxide, freezing it into ice pops, and then shaping them into spheres in a mold to simulate hail, as described in the prior art patent "US10119739B2 / HAIL PRODUCING MACHINE".

[0004] However, the existing technologies described above all produce regular spherical hailstones. As is well known, hailstones are hard, spherical, conical, or irregularly shaped solids, and they often fall in irregular forms in the atmosphere. The impact of irregular hailstones on aircraft differs significantly in terms of mechanical effects compared to regular hailstones. When regular spherical hailstones impact an aircraft structure, their contact area and stress distribution are relatively uniform. In contrast, irregular hailstones in the real environment, due to their varied shapes, experience localized stress concentration upon impact, leading to more complex damage patterns. Existing technologies cannot accurately reproduce this non-uniform impact characteristic in regular hailstones, resulting in discrepancies between experimental data and actual operating conditions. This makes it difficult for experimental results to meet the accuracy requirements of aircraft impact resistance design, thus affecting the reliability of structural safety assessments.

[0005] In view of the above, this application is hereby submitted. Summary of the Invention

[0006] To address one of the aforementioned technical problems, this application provides a hail production device.

[0007] This application provides the following technical solution: The primary objective of this application is to provide a hail production device, comprising: A hail freezing device, comprising a fixed base and a rotating tank rotatably disposed on the fixed base, the rotating tank having an ice-making chamber; A cold air supply device is connected to the hail solidification device and is used to supply cold air to the ice-making chamber. A steam supply device is connected to the hail solidification device and is used to introduce steam into the ice-making chamber. A drive mechanism, which is in transmission cooperation with the rotating tank, is used to drive the rotating tank to rotate; An airflow enhancement mechanism, connected to the hail solidification device, is used to introduce an upward lifting airflow into the ice-making chamber.

[0008] Optionally, the mounting base includes a top base and a bottom base; The top seat and the bottom seat are arranged vertically at intervals; The rotating tank has a top opening and a bottom opening, with a top seat covering the top opening and a bottom seat covering the bottom opening; The rotating tank is rotatably engaged with the top seat and the bottom seat, respectively; The top seat has a cold air inlet, which is connected to the ice-making chamber; The air supply device is connected to the air inlet.

[0009] Optionally, a steam inlet is provided on the bottom seat, and the steam inlet is connected to the ice-making chamber; The steam supply device is connected to the steam inlet.

[0010] Optionally, an air outlet is provided on the top seat, and an air inlet is provided on the bottom seat; The airflow increasing mechanism includes a circulation pipe and an airflow boosting device. The two ends of the circulation pipe are respectively connected to the air outlet and the air inlet, and the airflow increasing device is disposed on the circulation pipe.

[0011] Optionally, a toothed ring is provided around the outer wall of the rotating tank; The drive mechanism includes a power component and a drive gear, wherein the drive gear meshes with the gear ring. The power unit and the drive gear are coupled to drive the rotating tank to rotate.

[0012] Optionally, the inner wall of the rotating tank is provided with ribs that extend along the rotation axis of the rotating tank and extend circumferentially along the rotating tank.

[0013] Optionally, the inner wall of the rotating tank is covered with a hydrophobic layer.

[0014] Optionally, the hydrophobic layer includes an adhesive layer, a hydrophobic fabric base layer, and a hydrophobic pile layer; The adhesive layer and the hydrophobic fleece layer are respectively disposed on both sides of the hydrophobic fabric base layer along the thickness direction; The adhesive layer is bonded to the inner wall of the rotating tank, and the hydrophobic fluff layer is exposed to the ice-making cavity.

[0015] Optionally, the cold air supply device is a cryogenic liquefied nitrogen storage tank; The steam supply device is a high-temperature and high-pressure steam storage tank.

[0016] A second objective of this application is to provide a method for preparing hail using the hail production equipment described above, comprising: Step S1: Control the steam supply device to introduce cold air into the ice-making chamber; Step S2: Control the drive mechanism to drive the rotating tank to rotate and form a circumferential rotating airflow. Control the airflow pressurization mechanism to introduce high-pressure airflow from the bottom of the rotating tank to form a lifting airflow from bottom to top. Step S3: Control the steam supply device to introduce water vapor into the ice-making chamber. The water vapor suspends and moves in the rotating tank to form hail. After the hail is formed, it falls into the bottom of the hail solidification device.

[0017] By adopting the above technical solution, this application has the following beneficial effects: The hail production equipment provided in this application closely approximates the natural hail formation process during production, overcoming the shortcomings of traditional hail preparation methods that involve solidification from the outside in, resulting in hailstones with regular shapes that do not conform to real conditions. Furthermore, the hailstones are naturally formed at low temperatures, avoiding difficulties in demolding. It can produce simulated hailstones with irregular shapes, densities, and hardness extremely similar to real hailstones, providing more reliable test materials for aircraft hail impact testing, improving the accuracy and reliability of test data, and having significant implications for aircraft structural safety assessment. Attached Figure Description

[0018] The accompanying drawings, which form part of this application, are provided to further illustrate the invention. The illustrative embodiments and descriptions of the invention are used to explain the invention but do not constitute an undue limitation thereof. Clearly, the drawings described below are merely some embodiments, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0019] Figure 1 This diagram shows the connection structure between the various structures of the hail production equipment provided in this embodiment of the present disclosure; Figure 2 This diagram illustrates the meshing structure between the rotating tank and the drive gear in the hail production equipment provided in this embodiment of the present disclosure. Figure 3 A perspective structural schematic diagram of the rotating tank of the hail production equipment provided in this embodiment of the present disclosure is shown; Figure 4 This diagram illustrates the hierarchical structure of the rotating tank wall of a hail production device provided in an embodiment of this disclosure.

[0020] In the attached diagram: Hailstone freezing device 1, fixed base 11, top base 111, cold air inlet 1111, bottom base 112, steam inlet 1121, air inlet 1122, rotating tank 12, toothed ring 121, rib 122, hydrophobic layer 123, adhesive layer 1231, hydrophobic fabric base layer 1232, hydrophobic fleece layer 1233, cold air supply device 2, steam supply device 3, drive gear 4, airflow enhancement mechanism 5, circulation pipe 51, airflow pressurization device 52, water droplet 6. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of the present invention clearer, the technical solutions of the present invention will be described in more detail below with reference to the accompanying drawings of the preferred embodiments. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of the present invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0022] In the description of this embodiment, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this embodiment. Example 1

[0023] like Figure 1 and Figure 4 As shown in the illustration, this application provides a hail production device, including a hail solidification device 1, a cold air supply device 2, a steam supply device 3, a drive mechanism, and an airflow enhancement mechanism 5. The hail solidification device 1 includes a fixed base 11 and a rotating tank 12 rotatably disposed on the fixed base 11, the rotating tank 12 having an ice-making chamber. The cold air supply device 2 is connected to the hail solidification device 1 and is used to supply cold air to the ice-making chamber. The steam supply device 3 is connected to the hail solidification device 1 and is used to supply water vapor to the ice-making chamber. The drive mechanism is driven by the rotating tank 12 and is used to drive the rotating tank 12 to rotate. The airflow enhancement mechanism is connected to the hail solidification device 1 and is used to supply an upward lifting airflow to the ice-making chamber.

[0024] Hail in nature usually forms in strong convective clouds and generally refers to solid, spherical precipitation particles with a diameter greater than 5 millimeters. The formation of hail requires the following three conditions: (1) the presence of updrafts in the atmosphere; (2) the presence of temperature zones with different altitudes in the atmosphere. This temperature difference causes water vapor in the updrafts to cool at higher altitudes, forming water droplets and graupel; (3) the graupel rises and falls continuously under the impetus of the updrafts, constantly combining with snowflakes or small water droplets to grow and solidify, forming hail with alternating layers of transparency and opacity.

[0025] The hail production equipment provided in this application includes a cold air supply device 2 connected to the upper part of a hail solidification device 1, a steam supply device 3 connected to the lower part of the hail solidification device 1, and an airflow enhancement mechanism connected to the lower part of the hail solidification device 1. The steam supply device 3 injects water vapor into the hail solidification device 1, and the airflow enhancement mechanism 5 injects a lifting airflow from below the hail solidification device 1 into it. Under the action of the lifting airflow, the water vapor rises and, upon contact with the cold air supplied by the cold air supply device 2, naturally condenses into small ice nuclei. As the ice nuclei rise, the lifting force gradually decreases, and they fall under the influence of gravity, contacting the water vapor injected by the steam supply device 3. The water vapor condenses on the ice nuclei. As the ice nuclei fall, the lifting force increases, causing them to rise again. Under the action of cold air, the water vapor coating the ice nuclei also freezes. This process repeats continuously with the continuous input of water vapor, causing the ice nuclei to gradually grow, forming layers of transparent or opaque hail. Meanwhile, the rotation of the rotating tank 12 causes water vapor to form a circumferential rotating airflow in the ice-making cavity, further simulating the airflow disturbance that hail experiences during its rise and fall in nature, making the generated hail shapes more irregular and closer to the hail morphology in the real environment.

[0026] The hail production equipment provided in this application closely approximates the natural hail formation process during production, overcoming the shortcomings of traditional hail preparation methods that involve solidification from the outside in, resulting in hailstones with regular shapes that do not conform to real conditions. Furthermore, the hailstones are naturally formed at low temperatures, avoiding difficulties in demolding. It can produce simulated hailstones with irregular shapes, densities, and hardness extremely similar to real hailstones, providing more reliable test materials for aircraft hail impact testing, improving the accuracy and reliability of test data, and having significant implications for aircraft structural safety assessment.

[0027] In some possible implementations, the fixed base 11 includes a top base 111 and a bottom base 112, which are spaced vertically apart. The rotating tank 12 has a top opening and a bottom opening, with the top base 111 covering the top opening and the bottom base 112 covering the bottom opening. The rotating tank 12 is rotatably engaged with the top base 111 and the bottom base 112, respectively. The top base 111 has a cold air inlet 1111, which communicates with the ice-making chamber. The cold air supply device 2 is connected to the cold air inlet 1111. Bearings can be provided between the top opening and the top base 111, and between the bottom opening and the bottom base 112, to achieve smooth rotation of the rotating tank 12 relative to the top base 111 and the bottom base 112, reduce friction during rotation, and improve the operational stability and service life of the equipment. Meanwhile, the cold air inlet 1111 is set on the non-rotating top seat 111, which makes the installation simpler and avoids the problem of connecting pipes getting tangled or damaged due to the rotation of the rotating tank 12, ensuring that the cold air is stably and continuously supplied to the ice-making chamber.

[0028] In some possible implementations, a steam inlet 1121 is provided on the base 112, the steam inlet 1121 communicating with the ice-making chamber, and the steam supply device 3 is connected to the steam inlet 1121. By placing the steam inlet 1121 on the base 112, water vapor can be sprayed upwards from the bottom, allowing the ice nuclei to fully contact the water vapor during their continuous rise and fall. This ensures the efficient and stable production of simulated hail that more closely resembles real hail.

[0029] In some possible implementations, an air outlet is provided on the top seat 111, and an air inlet 1122 is provided on the bottom seat 112. The airflow increasing mechanism includes a circulation pipe 51 and an airflow booster device 52. The two ends of the circulation pipe 51 are connected to the air outlet and the air inlet 1122, respectively, and the airflow booster device is mounted on the circulation pipe 51. This design forms an internal airflow circulation system. Air is drawn in from the air inlet 1122 by the airflow booster device 52, passes through the circulation pipe 51, and is blown out from the air outlet, forming an upward lifting airflow. This provides power for the rise and fall of hailstones within the ice-making chamber, simulating the airflow environment during hail formation in nature. The circulation pipe 51 and the airflow booster device 52 are used to provide a certain vertical support force for the flow field, thereby achieving controllable hailstone size and mass.

[0030] In some possible implementations, a toothed ring 121 is provided around the outer wall of the rotating tank 12. The driving mechanism includes a power component and a drive gear 4. The drive gear 4 meshes with the toothed ring 121, and the power component and drive gear 4 are in a transmission engagement to drive the rotating tank 12 to rotate. Through the meshing transmission of the toothed ring 121 and drive gear 4, the rotation speed and direction of the rotating tank 12 can be precisely controlled, like a washing machine, to agitate the airflow, making the rotating airflow formed by water vapor in the ice-making chamber more stable and uniform, further improving the irregularity of the hailstone shape and the consistency of its quality.

[0031] The power assembly includes a motor and a gear set. The output shaft of the motor is connected to the input gear of the gear set, and the output gear of the gear set is connected to the gear ring 121.

[0032] In some possible implementations, raised ribs 122 are provided on the inner wall of the rotating tank 12. The raised ribs 122 extend along the rotation axis of the rotating tank 12 and extend circumferentially along the rotating tank 12. The raised structure on the inner wall creates a relatively stable vortex airflow within the cavity. This design not only enhances the mixing effect of water vapor within the ice-making cavity but also subjects the generated hailstones to more complex airflow during formation, further simulating the turbulence and vortex effects experienced by hailstones in clouds in nature. This results in hailstones that are closer in shape and structure to hailstones in the real environment.

[0033] In some possible implementations, the inner wall of the rotating tank 12 is covered with a hydrophobic layer 123. The hydrophobic layer 123 can prevent water vapor from excessively condensing on the inner wall of the rotating tank 12 to form water droplets 6, reducing the interference of water droplets 6 on the hail formation process and ensuring the quality and shape of the hail. At the same time, another function is to assist in the formation of small ice particles for further adhesion.

[0034] In some possible implementations, the hydrophobic layer 123 includes an adhesive layer 1231, a hydrophobic fabric base layer 1232, and a hydrophobic flock layer 1233. The adhesive layer 1231 and the hydrophobic flock layer 1233 are respectively disposed on both sides of the hydrophobic fabric base layer 1232 along the thickness direction. The adhesive layer 1231 is bonded to the inner wall of the rotating tank 12, and the hydrophobic flock layer 1233 is exposed to the ice-making cavity. This multi-layered hydrophobic layer 123 has better hydrophobic and abrasion resistance. The adhesive layer 1231 can firmly bond the hydrophobic fabric base layer 1232 to the inner wall of the rotating tank 12. The fabric base layer provides a base for flocking, and the hydrophobic flock layer 1233 can effectively prevent water droplets 6 from condensing on the tank wall, while also reducing the friction between hail and the inner wall of the rotating tank 12, protecting the surface quality of the hail.

[0035] In some possible implementations, the cold air supply device 2 is a cryogenic liquefied nitrogen storage tank, and the steam supply device 3 is a high-temperature, high-pressure steam storage tank. The cryogenic liquefied nitrogen storage tank can provide stable cryogenic cold air, ensuring that the temperature inside the ice-making chamber meets the requirements for hail formation, while the high-temperature, high-pressure steam storage tank can provide sufficient steam to meet the needs of hail growth. The cryogenic liquefied nitrogen storage tank and the high-temperature, high-pressure steam storage tank are respectively used to provide a cryogenic environment and for the mixing of steam and nitrogen to form hail of different densities. Example 2

[0036] like Figure 1 and Figure 2 As shown, this embodiment provides a hail preparation method using the hail production equipment described in Embodiment 1, comprising: Step S1: Control the steam supply device 3 to introduce cold air into the ice-making chamber; Step S2: Control the drive mechanism to drive the rotating tank 12 to rotate and form a circumferential rotating airflow. Control the airflow pressurization mechanism to introduce high airflow from the bottom of the rotating tank 12 to form a lifting airflow from bottom to top. Step S3: Control the steam supply device 3 to introduce water vapor into the ice-making chamber. The water vapor suspends and moves in the rotating tank 12 to form hail. After the hail is formed, it falls into the bottom of the hail solidification device 1.

[0037] The hail preparation method provided in this embodiment first involves drying the air to remove water vapor, then injecting an appropriate amount of cryogenic liquefied nitrogen to create a low-temperature environment. Preferably, the temperature inside the solidification chamber needs to be below -0°C, and cryogenic nitrogen is continuously injected to maintain the ultra-low temperature environment. The drive mechanism and airflow pressurization device 52 are activated, and the airflow pressure distribution and the mass size of the simulated ball that can be withstood are calculated using CFD (computational fluid dynamics). The rotation speed and pressurization intensity are adjusted to preset values. An appropriate amount of water vapor is injected into the ice-making chamber, causing small ice particles to gradually condense into hailstones of a certain size. Once the hailstones reach a certain mass, they fall into the hailstone collection area and no longer participate in the low-temperature airflow movement.

[0038] The hail preparation method provided in this embodiment can produce hailstones of different sizes, densities, and shapes by precisely controlling the operating parameters of each device, such as the temperature and flow rate of the cold air supply device 2, the amount and pressure of water vapor in the steam supply device 3, the rotational speed of the drive mechanism, and the pressurization intensity of the airflow pressurization mechanism. During the preparation process, key parameters such as temperature, humidity, and airflow speed within the ice-making cavity can be monitored in real time, and the operating status of each device can be adjusted promptly based on the monitoring results to ensure the quality and efficiency of hail preparation. Furthermore, this hail preparation method has advantages such as simple operation, safety, reliability, and high repeatability, meeting the needs of different fields for simulated hail and providing strong support for related research and experiments.

[0039] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, are covered within the scope of protection of the present invention.

Claims

1. A hail production device, characterized in that, include: A hail freezing device, comprising a fixed base and a rotating tank rotatably disposed on the fixed base, the rotating tank having an ice-making chamber; A cold air supply device is connected to the hail solidification device and is used to supply cold air to the ice-making chamber. A steam supply device is connected to the hail solidification device and is used to introduce steam into the ice-making chamber. A drive mechanism, which is in transmission cooperation with the rotating tank, is used to drive the rotating tank to rotate; An airflow enhancement mechanism, connected to the hail solidification device, is used to introduce an upward lifting airflow into the ice-making chamber.

2. The hail production equipment according to claim 1, characterized in that, The mounting base includes a top base and a bottom base; The top seat and the bottom seat are arranged vertically at intervals; The rotating tank has a top opening and a bottom opening, with a top seat covering the top opening and a bottom seat covering the bottom opening; The rotating tank is rotatably engaged with the top seat and the bottom seat, respectively; The top seat has a cold air inlet, which is connected to the ice-making chamber; The air supply device is connected to the air inlet.

3. The hail production equipment according to claim 2, characterized in that, A steam inlet is provided on the bottom seat, and the steam inlet is connected to the ice-making chamber; The steam supply device is connected to the steam inlet.

4. The hail production equipment according to claim 2, characterized in that, An air outlet is provided on the top seat, and an air inlet is provided on the bottom seat; The airflow increasing mechanism includes a circulation pipe and an airflow boosting device. The two ends of the circulation pipe are respectively connected to the air outlet and the air inlet, and the airflow increasing device is disposed on the circulation pipe.

5. The hail production equipment according to claim 1, characterized in that, A toothed ring is provided around the outer wall of the rotating tank; The drive mechanism includes a power component and a drive gear, wherein the drive gear meshes with the gear ring. The power unit and the drive gear are coupled to drive the rotating tank to rotate.

6. The hail production equipment according to claim 1, characterized in that, The inner wall of the rotating tank is provided with raised ribs, which extend along the rotation axis of the rotating tank and also extend circumferentially along the rotating tank.

7. The hail production equipment according to claim 1, characterized in that, The inner wall of the rotating tank is covered with a hydrophobic layer.

8. The hail production equipment according to claim 7, characterized in that, The hydrophobic layer includes an adhesive layer, a hydrophobic fabric base layer, and a hydrophobic pile layer; The adhesive layer and the hydrophobic fleece layer are respectively disposed on both sides of the hydrophobic fabric base layer along the thickness direction; The adhesive layer is bonded to the inner wall of the rotating tank, and the hydrophobic fluff layer is exposed to the ice-making cavity.

9. The hail production equipment according to any one of claims 1-8, characterized in that, The cold air supply device is a cryogenic liquefied nitrogen storage tank; The steam supply device is a high-temperature and high-pressure steam storage tank.

10. The hail preparation method of the hail production equipment according to any one of claims 1-9, characterized in that, include: Step S1: Control the steam supply device to introduce cold air into the ice-making chamber; Step S2: Control the drive mechanism to drive the rotating tank to rotate and form a circumferential rotating airflow. Control the airflow pressurization mechanism to introduce high-pressure airflow from the bottom of the rotating tank to form a lifting airflow from bottom to top. Step S3: Control the steam supply device to introduce water vapor into the ice-making chamber. The water vapor suspends and moves in the rotating tank to form hail. After the hail is formed, it falls into the bottom of the hail solidification device.

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