Ejecting type low-temperature rain and snow environment icing wind tunnel simulation test device

Abstract

The invention provides an injection type low-temperature rain and snow environment icing wind tunnel simulation test device, and the device is characterized in that an open type main air duct is arranged in a thermal insulation maintenance structure, and the open type main air duct comprises an air duct regulation and control section, an air duct gradual contraction section, an air duct test section, an air duct transition section, an air duct injection section and an air duct diffusion section which are connected in sequence; an exhaust fan is arranged at an exhaust hole in the rear end of the heat-preservation maintenance structure; a temperature sensor and a cold air diffuser are arranged in the heat preservation maintenance structure, and the cold air diffuser is connected with an external refrigeration turbine; an atomizing nozzle is arranged in the air duct regulation and control section and is connected with a spraying system; an ejector is arranged in the air duct ejection section; a test piece is placed in the air duct test section; the refrigerating turbine and the ejector are respectively connected with the refrigerating unit; the cold source control valve, the injection main flow valve, the spraying system and the temperature sensor are all in signal connection with the measurement and control system. The simulation environment can be optimized and adjusted, and high efficiency and energy saving of a wind tunnel test system are achieved while ground low-temperature rain and snow environment simulation is met.

Description

Technical Field

[0001] The invention relates to the field of aircraft anti-icing / de-icing, and in particular to an ejection type low-temperature rain and snow environment ice wind tunnel simulation test device. Background Art

[0002] When an aircraft flies under icing weather conditions or is parked in the open air, ice is easily accumulated on the surfaces of key components such as the leading edge slats, tail fins, and engine air inlets. Excessive ice accumulation will lead to a decrease in the aircraft's aerodynamic performance and handling performance, threatening flight safety, so anti-icing measures need to be taken for these components. At present, the main anti-icing technologies used on aircraft are thermal anti-icing technologies, including engine hot air anti-icing and electric heating anti-icing. Thermal anti-icing technology mainly heats the surfaces of components such as the leading edge slats, tail fins, and engine air inlets to make the surface temperature higher than 0°C and prevent ice accumulation (in some cases, it is necessary to heat to a higher surface temperature to evaporate all the water on the protective surface to prevent overflow from the protective area to form ice ridges). With the introduction of the new aircraft design concept of more electric / all-electric aircraft, the electric anti-icing system came into being. Compared with the hot air anti-icing system, when using electrical energy as the energy source of the wing leading edge anti-icing system, the energy consumed is greatly reduced under the same anti-icing effect conditions. At the same time, the electric heating method can periodically and accurately control the heating power, which can further reduce the energy consumption of the anti-icing system. With the emergence of new materials, various passive anti-icing systems based on hydrophobic materials have also emerged.

[0003] In order to effectively verify the effectiveness of the aircraft anti-icing system, a natural icing flight test can be used. Although the natural icing flight test is conducted in a real environment and the verification effect is the most reliable, it is costly, dangerous, and has a long period. The ice wind tunnel test avoids the above problems on the basis of simulating the real icing meteorological conditions as much as possible, but due to the limitations of the test conditions, it is necessary to scale down the test environment and the test object. Ruff proposed a similarity theory for ice wind tunnel tests, which mainly includes similar droplet trajectories, similar collected water volume, similar thermodynamic parameters, etc., and designed an icing test for verification. The results showed that the similarity theory is feasible, but has certain limitations. Bilanin then modified the original similarity theory based on experimental observation results and added considerations for the similarity of water film and water droplet motion. Later, this correction was also considered to take into account the Weber number of different characteristic sizes. Kind et al. conducted a study on the water film flow test on the open ice surface under the ice wind tunnel based on the similarity of the Weber number. The test showed that under the same ambient temperature, the scaled-down test effect is better when the Weber number is similar. In recent years, researchers have also conducted experimental studies on thermal anti-icing systems operating under incomplete evaporation on wet surfaces, based on the principle that the evaporation rates of water at sea level and at different altitudes are similar, starting from the perspective of environmental height similarity.

[0004] Icing wind tunnel verification can effectively save flight test costs, but the current maintenance and operation costs of icing wind tunnels are still relatively high, and the energy consumption for driving gas flow is huge. In order to effectively reduce the energy consumption of icing wind tunnel tests, the present invention adopts an ejection-type structural design. Under the premise of meeting the flow characteristics of wind tunnel tests, the energy consumption of icing wind tunnels can be effectively reduced. In addition, the position of multiple nozzles can be adjusted to achieve simulation of different icing environments. This is particularly suitable for small-scale verification tests and provides a new idea for simulating low-temperature rain and snow environments. Summary of the invention

[0005] In order to realize low-cost low-temperature rain and snow environment simulation, the present invention provides an ejection-type low-temperature rain and snow environment ice wind tunnel simulation test device, which can realize low-temperature freezing rain, wet snow, dry snow and other environmental simulations under different temperature environments.

[0006] In order to achieve the above-mentioned purpose, the technical solution provided by the present invention is: an ejection-type low-temperature rain and snow environment ice wind tunnel simulation test device, comprising: a thermal insulation maintenance structure; an open main air duct is arranged in the thermal insulation maintenance structure, and the open main air duct includes a duct control section, a duct tapering section, an duct test section, a duct transition section, a duct ejection section, and a duct expansion section connected in sequence from front to back; an exhaust fan is arranged at the exhaust hole at the rear end of the thermal insulation maintenance structure; a cold air diffuser is arranged at the top of the thermal insulation maintenance structure, and the cold air diffuser is connected to an external refrigeration turbine; a temperature sensor is also arranged in the thermal insulation maintenance structure; an atomizing nozzle is arranged in the air duct control section, and the atomizing nozzle is connected to an external spray system; an ejector is arranged in the air duct ejection section; a test piece is placed in the air duct test section; the refrigeration turbine and the ejector are connected to the refrigeration unit through a cold source control valve and an ejection mainstream valve respectively; the cold source control valve, the ejection mainstream valve, the spray system and the temperature sensor are all connected to the measurement and control system signal.

[0007] Preferably, the atomizing nozzle is an adjustable array nozzle assembly.

[0008] Furthermore, the array of atomizing nozzles is placed on a bracket, and the bracket is placed on a slide rail.

[0009] The spray system includes a small air compressor and a deionized water storage tank. The small air compressor is connected to the atomizing nozzle and the deionized water storage tank through an air circuit valve and a water circuit valve respectively, and the atomizing nozzle is also connected to the deionized water storage tank.

[0010] The invention provides an ejection type low temperature rain and snow environment ice wind tunnel simulation test device which can be optimized and adjusted according to different required simulation environments, thereby simulating different low temperature rain and snow environments from conventional low temperature icing to freezing drizzle or freezing rain, and can achieve high efficiency and energy saving of the wind tunnel test system while meeting the ground low temperature rain and snow environment simulation. The invention can be applied to the fields of aircraft anti-icing, ground freezing rain and other environmental simulations.

[0011] The beneficial effects of the present invention compared to the prior art are: the injection-type structural design is adopted to effectively reduce the energy consumption of the icing wind tunnel while meeting the flow characteristics of the wind tunnel test. In addition, the simulation of different low-temperature rain and snow environments can be achieved through the adjustment of multiple nozzle positions and the control and matching of temperature and wind speed. It is particularly suitable for small-scale verification tests and reduces the simulation cost of low-temperature rain and snow environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 The schematic diagram of the principle of the ejection type low temperature rain and snow environment ice wind tunnel simulation test device provided by the present invention;

[0013] Figure 2 Schematic diagram of the installation of the array nozzle provided by the present invention;

[0014] Figure 3 A schematic diagram of the arrangement of the diffuser provided by the present invention;

[0015] Figure 4 A schematic diagram of the spray system principle provided by the present invention.

[0016] In the figure, 1-compressed air, 2-refrigeration unit, 3-cold source control valve, 4-refrigeration turbine, 5-cold air diffuser, 6-atomizing nozzle, 7-test piece, 8-injector, 9-spray system, 10-injection mainstream valve, 11-air duct control section, 12-air duct tapering section, 13-air duct test section, 14-air duct transition section, 15-air duct injection section, 16-air duct expansion section, 17-exhaust fan, 18 thermal insulation maintenance structure, 19-temperature sensor, 20-measurement and control system. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0018] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0019] Reference Figure 1 The present embodiment provides an ejection-type low-temperature rain and snow environment ice wind tunnel simulation test device, comprising: a heat preservation maintenance structure 18; an open main air duct is arranged in the heat preservation maintenance structure 18, and the open main air duct comprises, from front to back, an air duct control section 11, an air duct tapering section 12, an air duct test section 13, an air duct transition section 14, an air duct ejection section 15, and an air duct pressure expansion section 16 connected in sequence;

[0020] An exhaust fan 17 is provided at the exhaust hole at the rear end of the thermal insulation maintenance structure 18; a cold air diffuser 5 is provided at the top of the thermal insulation maintenance structure 18, and the cold air diffuser 5 is connected to an external refrigeration turbine 4; a temperature sensor 19 is also provided in the thermal insulation maintenance structure 18;

[0021] An atomizing nozzle 6 is provided in the air duct control section 11, and the atomizing nozzle 6 is connected to an external spray system 9;

[0022] An ejector 8 is provided in the air duct ejection section 15; the test piece 7 is placed in the air duct test section 13;

[0023] The refrigeration turbine 4 and the ejector 8 are connected to the refrigeration unit 2 through the cold source control valve 3 and the ejector main flow valve 10 respectively;

[0024] The cold source control valve 3 , the injection main flow valve 10 , the spray system 9 and the temperature sensor 19 are all connected to the measurement and control system 20 by signal.

[0025] The open main air duct and the ejector 8 form an ejector assembly, which can adjust the ejection flow rate as needed, thereby expanding the wind tunnel simulation wind speed range. The open main air duct is provided with a non-uniform grid to achieve relative uniformity of the air duct flow field. The ejector 8 can achieve an ejection ratio in the range of 1:1-1:4.

[0026] The atomizing nozzle 6 is an adjustable array nozzle assembly. By replacing the nozzle and adjusting the array parameters, spray adjustment with different particle sizes and liquid water contents can be achieved, thereby achieving simulation of different environments.

[0027] The refrigeration unit 2 distributes the compressed air 1 through the cold source control valve 3 and the injection main flow valve 10, and adjusts the nozzle parameters to simulate different low temperature conditions such as freezing rain and ice. The refrigeration unit 2 includes a steam compression refrigerator, which can achieve two-stage refrigeration at -10℃ or -20℃. The refrigeration turbine 4 is arranged at the outlet of the refrigeration unit 2 to provide a low-temperature cold air source with a limit of -80℃.

[0028] The following is a detailed introduction to the ejection-type low-temperature rain and snow environment ice wind tunnel simulation test device.

[0029] Reference Figure 1 The open main air duct is placed in the thermal insulation maintenance structure 18, and the main environmental control needs to be achieved through temperature control and flow control, and the simulation of different low-temperature rain and snow environments such as low-temperature freezing rain, wet snow, and dry snow can be achieved through the control of the spray system 9.

[0030] Figure 1 The open main air duct in the test section is composed of multiple pipe sections to ensure uniform flow in the test section. By adjusting the mainstream pressure flow parameters in the air duct injection section 15, the flow velocity in the open main air duct can be adjusted within a range of 0-70 m / s. Figure 1 The cold source control valve 3 in the refrigeration turbine 4 regulates the flow pressure to adjust the temperature flow of the cold air source to control the temperature in the thermal insulation maintenance structure 18 to be stable at an allowable value.

[0031] Reference Figure 2 The array of atomizing nozzles 6 shown is placed on a bracket 61. The adjustable array nozzle assembly can adjust the spacing between nozzles in the horizontal and vertical directions within a range of 5-40 cm, and the bracket 61 is placed on a slide rail 62 to adjust the distance between the nozzle and the test section to match the ambient temperature and wind tunnel wind speed, thereby simulating different low-temperature rain and snow environments such as freezing rain, wet snow, and dry snow.

[0032] Reference Figure 3 The cold air diffuser 5 achieves uniform blowing of cold air in the thermal insulation protection structure 18 by diffusing the cold air, so as to ensure uniform cooling in the thermal insulation protection structure 18.

[0033] As an optional embodiment, the cold air diffuser 5 can use the opposite side air intake, control the cold air source to -20℃, the wind speed to 10m / s, the cold air array spray port 51 is more than 50cm away from the test section, and after the temperature stabilizes, the spray system is turned on and maintained at 1g / m 3 The liquid water content can realize the environmental simulation conditions of dry snow in the test section.

[0034] Reference Figure 4 The spray system 9 includes a small air compressor 91 and a deionized water storage tank 92. The small air compressor 91 is connected to the atomizing nozzle 6 and the deionized water storage tank 92 through an air circuit valve 93 and a water circuit valve 94, respectively. The atomizing nozzle 6 is also connected to the deionized water storage tank 92. The small air compressor 91 provides high-pressure gas, the water circuit valve 94 controls the water circuit pressure in the deionized water storage tank 92, and the air circuit valve 93 directly enters the atomizing nozzle 6. Through different pressure ratios of the water circuit and the air circuit, the control of different atomized particle sizes and liquid water contents is achieved to simulate different working conditions.

[0035] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An ejection type low temperature rain and snow environment ice wind tunnel simulation test device, characterized in that: include: The heat preservation and maintenance structure (18) is provided with an open main air duct, and the open main air duct includes an air duct control section (11), an air duct tapering section (12), an air duct test section (13), an air duct transition section (14), an air duct ejection section (15), and an air duct pressure expansion section (16) which are connected in sequence from front to back; An exhaust fan (17) is provided at the exhaust hole at the rear end of the thermal insulation protection structure (18); A cold air diffuser (5) is provided on the top of the heat preservation protection structure (18), and the cold air diffuser (5) is connected to an external refrigeration turbine (4); A temperature sensor (19) is also provided in the heat preservation and maintenance structure (18); An atomizing nozzle (6) is provided in the air duct control section (11), and the atomizing nozzle (6) is connected to an external spray system (9); An ejector (8) is provided in the air duct ejection section (15); a test piece (7) is placed in the air duct test section (13); The refrigeration turbine (4) and the ejector (8) are connected to the refrigeration unit (2) via the cold source control valve (3) and the ejector main flow valve (10) respectively; The cold source control valve (3), the injection main flow valve (10), the spray system (9) and the temperature sensor (19) are all connected to the measurement and control system (20) via signals.

2. The device for simulating ice wind tunnel test in low-temperature rain and snow environment according to claim 1 is characterized in that: The atomizing nozzle (6) is an adjustable array nozzle assembly.

3. The device for simulating ice wind tunnel test in low-temperature rain and snow environment according to claim 2 is characterized in that: The array of atomizing nozzles (6) is placed on a bracket (61), and the bracket (61) is placed on a slide rail (62).

4. The device for simulating ice wind tunnel test in low-temperature rain and snow environment according to claim 1 is characterized in that: The spray system (9) comprises a small air compressor (91) and a deionized water storage tank (92). The small air compressor (91) is connected to the atomizing nozzle (6) and the deionized water storage tank (92) through an air circuit valve (93) and a water circuit valve (94) respectively. The atomizing nozzle (6) is also connected to the deionized water storage tank (92).

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