Dual air volume driving eight energy unit control device for high and low temperature test of aircraft canopy

Abstract

The present application belongs to the technical field of aircraft thermal intensity test, and relates to a double-air-volume driving eight-energy-unit control device for high and low temperature test of aircraft canopy cover, comprising an air inlet, a short tee, a cold path valve, a hot path valve, a long tee, a liquid nitrogen evaporator, an electric furnace, an inclined square tube, a rectifier section, a partition, a test section, an air flow regulating valve, an air return and a control system; two air inlets are respectively connected with two groups of air outlet of air fans to form a double-air-volume driving structure; each air inlet is divided into an upper hot path and a lower cold path through a short tee, the hot path is controlled by a hot path valve, and the cold path is controlled by a cold path valve; each group of hot path and cold path is divided into two groups of branches through a long tee, the hot path branch is provided with an electric furnace, and the cold path branch is provided with a liquid nitrogen evaporator, so that four groups of electric furnaces and four groups of liquid nitrogen evaporators are formed to form eight energy units; the spread temperature and the heading temperature of circulating air flow are synchronously and jointly controlled, and then the spread temperature field uniformity and the heading temperature gradient of the canopy cover are precisely adjusted, so that the ground test conditions are closer to the actual flight conditions.

Description

Technical Field

[0001] This invention belongs to the field of aircraft thermal strength testing technology, specifically relating to a dual-airflow driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopies. Background Technology

[0002] High and low temperature tests on aircraft canopies are indispensable ground-based assessment tests in the aircraft development process. Their core purpose is to verify whether the static strength and stiffness of the canopy structure under combined high and low temperature load conditions meet the design requirements, and to provide key test data support for the strength analysis of the canopy structure.

[0003] Currently, all such tests are conducted using a high and low temperature test bench for the canopy. During the test, the canopy is installed in the test section of the test bench. A fan drives the gas flow in the pipeline, and a liquid nitrogen evaporator is used to cool the airflow, while an electric furnace is used to heat the airflow, forming a high and low temperature circulating airflow. The high and low temperature loading is completed through convective heat exchange between the airflow and the surface of the canopy.

[0004] To ensure consistency between ground test conditions and actual flight conditions, the tests imposed stringent requirements on the spanwise temperature field uniformity and directional temperature gradient of the canopy surface. In existing technologies, canopy high and low temperature test rigs generally employ a single-airflow-driven dual-energy-unit control method. This method only includes one set of liquid nitrogen evaporators and one set of electric furnaces, making it impossible to precisely adjust the spanwise temperature distribution of the airflow, resulting in poor spanwise temperature field uniformity of the canopy during testing. Furthermore, this control method makes it difficult to flexibly adjust the directional temperature gradient of the airflow, causing significant differences between ground test conditions and actual flight environments, thus affecting the accuracy and reliability of the test data. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a dual-airflow-driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopies. This device enables simultaneous joint control of the spanwise and yaw temperatures of the circulating airflow, thereby precisely adjusting the uniformity of the spanwise temperature field and the yaw temperature gradient of the cockpit canopy, making the ground test conditions closer to actual flight conditions.

[0006] To achieve the aforementioned objectives, this invention provides a dual-airflow-driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopies. The device includes an air inlet, a short tee, a cold path valve, a hot path valve, a long tee, a liquid nitrogen evaporator, an electric furnace, a rhomboid tube, a rectifier section, a partition, a test section, an airflow regulating valve, a return air inlet, and a control system. The two air inlets are respectively connected to the air outlets of two sets of fans, forming a dual-airflow-driven structure. Each air inlet is split into an upper hot path and a lower cold path via a short tee. The hot path is controlled by a hot path valve, and the cold path is controlled by a cold path valve. Each set of hot and cold paths is split into... The system comprises two sets of branches: a hot branch equipped with an electric furnace and a cold branch equipped with a liquid nitrogen evaporator, forming a total of four sets of electric furnaces and four sets of liquid nitrogen evaporators, constituting eight energy units. The rectifying section is divided into four flow channels by partitions, with each of the four energy unit sets corresponding to one of the four flow channels. After temperature regulation by the energy units, the airflow is introduced into the rectifying section through a rhomboid tube, which is nested within the rectifying section and can freely extend and retract. The rectifying section connects to the test section, with a return air inlet at the rear end of the test section, where an airflow regulating valve is installed. The control system, by controlling the energy units and the airflow regulating valve, achieves joint regulation of the spanwise and heading temperatures of the circulating airflow.

[0007] Furthermore, the hot circuit valve and the cold circuit valve are open-close control valves. Under heating conditions, the cold circuit valve is closed and the hot circuit valve is open. Under cooling conditions, the cold circuit valve is open and the hot circuit valve is closed.

[0008] Furthermore, the four sets of liquid nitrogen evaporators and the four sets of electric furnaces are arranged side by side along the longitudinal direction, and the liquid nitrogen evaporators and electric furnaces facing each other vertically constitute a group of energy units, corresponding to one flow channel of the rectifier section.

[0009] Furthermore, the rectifying section is a square tube structure with three baffles welded in parallel along the longitudinal direction inside, dividing the flow channel inside the rectifying section into four independent flow channels, and each flow channel is equipped with a measuring tube (15) above it.

[0010] Furthermore, one end of the rhomboid tube is nested within the rectifying section and can freely expand and contract along the axial direction of the rectifying section to compensate for the thermal expansion and contraction deformation of the flow channel.

[0011] Furthermore, the valve plate of the airflow regulating valve is arranged along the longitudinal direction, and the valve plate can rotate vertically up and down around the valve plate axis. The adjustment range is ±45 degrees, where +45 degrees corresponds to the valve plate being completely closed downwards and -45 degrees corresponds to the valve plate being completely closed upwards.

[0012] Furthermore, the control system is configured with a set of PID controllers for the liquid nitrogen evaporator valve position and electric furnace power corresponding to each flow channel, so as to realize independent decoupled control of the temperature of the four flow channels.

[0013] Furthermore, two airflow regulating valves are arranged side by side along the span direction. The left airflow regulating valve regulates the heading temperature gradient of canopy zones 1 and 2, while the right airflow regulating valve regulates the heading temperature gradient of canopy zones 3 and 4.

[0014] Furthermore, the control system achieves synchronous control of the spanwise temperature field uniformity and the directional temperature gradient of the cockpit canopy through the coordinated operation of independent temperature control of four flow channels and zoned adjustment of dual airflow regulating valves.

[0015] This invention achieves synchronous joint control of the spanwise and azimuth temperatures of the circulating airflow through a synergistic design of dual airflow drive and eight energy units, combined with the flow channel separation structure of the rectifier section and the precise adjustment function of the airflow regulating valve. This significantly improves the uniformity of the spanwise temperature field of the canopy and the adjustment accuracy of the azimuth temperature gradient. The independent control design of the eight energy units ensures that the temperature regulation of each flow channel does not interfere with each other. With the help of the PID control algorithm, precise closed-loop temperature control is achieved. The expansion and contraction compensation structure of the rhomboid tube effectively solves the structural deformation problem caused by thermal expansion and contraction of the flow channel under high and low temperature environments, improving the stability and service life of the device. The overall device structure is reasonably designed and the control logic is clear, making the ground test conditions closer to the actual flight conditions and providing more reliable test data support for the structural strength analysis of the canopy. Attached Figure Description

[0016] 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. The drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 Schematic diagram of the high and low temperature test rig for the cockpit canopy; Figure 2 Schematic diagram of a dual-airflow-driven eight-energy-unit control device; Figure 3 Design drawing of a dual-airflow-driven eight-energy-unit control device; Figure 4 Design drawing for the rectifier section; Figure 5 A schematic diagram showing a rhomboid tube nested within a rectifying section; Figure 6 Design drawing for an airflow regulating valve; Figure 7 A schematic diagram illustrating the principle of cockpit canopy temperature control. Figure 8 A schematic diagram of the cockpit canopy's directional temperature gradient adjustment principle (valve plate in the center); Figure 9A schematic diagram of the cockpit canopy's directional temperature gradient adjustment principle (valve plate rotates upwards); Figure 10 A schematic diagram of the cockpit canopy's directional temperature gradient adjustment principle (valve plate rotates downwards). In the diagram: 1-Air inlet, 2-Short tee, 3-Cold circuit valve, 4-Hot circuit valve, 5-Long tee, 6-Liquid nitrogen evaporator, 7-Electric furnace, 8-Rhomboid tube, 9-Rectifying section, 10-Baffle plate, 11-Test section, 12-Airflow regulating valve, 13-Return air outlet, 14-Bend, 15-Measuring tube, 16-Bracket A, 17-Matching flange, 18-Bracket B, 19-Bracket C, 20-Round flange, 21-Fan adapter section, 22-Valve plate, 23-Valve plate shaft, 24-Cockpit cover, 25-Flow channel 1, 26-Flow channel 2, 27-Flow channel 3, 28-Flow channel 4, 29-Section 1, 30-Section 2, 31-Section 3, 32-Section 4, 33-Guide shroud. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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, 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.

[0019] The features and illustrative embodiments of various aspects of the present invention will now be described in detail. Numerous specific details are set forth in the following detailed description to provide a thorough understanding of the invention. However, it will be apparent to those skilled in the art that the invention may be practiced without requiring some of these specific details. The following description of embodiments is merely intended to provide a better understanding of the invention by illustrating examples of the invention. The invention is by no means limited to any specific setups and methods set forth below, but covers any improvements, substitutions, and modifications to structures, methods, and devices without departing from the spirit of the invention. Well-known structures and techniques are not shown in the drawings and the following description to avoid unnecessarily obscuring the invention.

[0020] In the description of this invention, it should be noted that the directions or positional relationships indicated by terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing and simplifying the invention, and should not be construed as limiting the invention. Furthermore, the use of ordinal numbers (e.g., "first and second," etc.) is for distinguishing objects and is not limited to this order, and should not be construed as indicating or implying relative importance.

[0021] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly, encompassing both direct connection and indirect connection via an intermediate medium. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0022] It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other, and the various embodiments can be referenced and cited in each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0023] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0024] This invention relates to a dual-airflow-driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopies. The device includes an air inlet, a short tee, a cold path valve, a hot path valve, a long tee, a liquid nitrogen evaporator, an electric furnace, a rhomboid tube, a rectifier section, a partition, a test section, an airflow regulating valve, a return air inlet, a measuring tube, and a control system. The two air inlets are respectively connected to the outlets of two sets of fans, forming a dual-airflow-driven structure. Airflow is driven by the fans to enter the device through the air inlets. Each air inlet is split into an upper hot path and a lower cold path via a short tee. The hot path is controlled by a hot path valve, and the cold path is controlled by a cold path valve. During heating, the cold path valve is closed. The hot circuit valve is closed and open; during cooling, the cold circuit valve is open and the hot circuit valve is closed. Each group of hot and cold circuits is divided into two branches via a long tee. Each branch of the hot circuit is equipped with an electric furnace, and each branch of the cold circuit is equipped with a liquid nitrogen evaporator, forming a total of 4 electric furnaces and 4 liquid nitrogen evaporators, constituting eight energy units, which are arranged side by side along the longitudinal direction. The rectifying section is a square tube structure, with 3 baffles evenly welded side by side along the longitudinal direction inside, dividing the flow channel inside the rectifying section into 4 independent flow channels. The liquid nitrogen evaporators and electric furnaces facing each other vertically form one energy unit group, and the 4 energy unit groups are sequentially connected to the 4 channels of the rectifying section along the longitudinal direction. The flow channels are one-to-one; each airflow path, after being conditioned by the corresponding liquid nitrogen evaporator or electric furnace, is introduced into the rectifying section through a rhomboid tube for rectification; one end of the rhomboid tube is nested inside the rectifying section and can freely expand and contract along the axial direction of the rectifying section to compensate for the thermal expansion and contraction deformation of the flow channels caused by the high and low temperature circulating airflow; the output end of the rectifying section is connected to the test section, and the canopy is installed inside the test section. The rectified airflow enters the test section and undergoes convective heat exchange with the surface of the canopy to achieve high and low temperature loading; two return air inlets are provided at the rear end of the test section, and each return air inlet is equipped with an airflow regulating valve; the valve plate of the airflow regulating valve is arranged along the spanwise direction, and the valve plate can rotate around... The valve plate shaft rotates vertically up and down, with an adjustment range of ±45 degrees. +45 degrees corresponds to the valve plate being completely closed downwards, and -45 degrees corresponds to the valve plate being completely closed upwards. The measuring tubes are welded above the corresponding pipes at the air inlet, rectifier section, and return air inlet, respectively, for real-time measurement of airflow velocity and temperature parameters. The control system is used to achieve coordinated control of the energy unit and the airflow regulating valve: by independently controlling the liquid nitrogen evaporator valve positions and electric furnace power corresponding to the four sets of flow channels, the spanwise temperature of the circulating airflow is adjusted; by adjusting the deflection angle of the airflow regulating valve, the airflow velocity is changed, thereby adjusting the axial temperature of the circulating airflow.

[0025] like Figure 3As shown, the assembly relationship of the components of the device specifically designed in this invention is as follows: the air inlets 1 of the two fan transition sections 21 are bolted to the air outlets of the two fans through flanges; a measuring tube 15 is welded on the top of the fan transition section 21 to measure the flow rate and temperature of the airflow at the air inlet 1; the other end of the fan transition section 21 is bolted to the short tee 2 through a round flange 20; the short tee 2 divides the pipeline into an upper hot circuit and a lower cold circuit; the short tee 2 is bolted to the cold circuit valve 3 and the hot circuit valve 4 through round flanges 20 respectively; the other end of the cold circuit valve 3 and the hot circuit valve 4 is bolted to the long tee 5 through round flanges 20.

[0026] The upper hot circuit's long tee 5 is divided into 4 branches, each branch connecting to one end of the electric furnace 7 and the rhomboid tube 8 in sequence. The long tee 5 is connected to the electric furnace 7, and the electric furnace 7 is connected to the rhomboid tube 8 via round flange 20 bolts. Similarly, the lower cold circuit's long tee 5 is divided into 4 branches, each branch connecting to one end of the liquid nitrogen evaporator 6 and the rhomboid tube 8 in sequence. The long tee 5 is connected to the liquid nitrogen evaporator 6, and the liquid nitrogen evaporator 6 is connected to the rhomboid tube 8 via round flange 20 bolts.

[0027] In the specific implementation process, the other end of the 8-way rhomboid tube 8 is nested inside the rectifier section 9. Three baffles 10 are welded inside the rectifier section 9 to form four flow channels. Measuring tubes 15 are welded above each flow channel. In order to ensure the stability of the entire device, the fitting point between the rhomboid tube 8 and the rectifier section 9 is supported by a bracket B18. The height of the bracket B18 can be adjusted by rotating it with a thread. The liquid nitrogen evaporator 6 and the electric furnace 7 are supported by a bracket C19. The height of the bracket C19 can be adjusted by rotating it with a thread.

[0028] The output end of the rectifier section 9 is fixed to the front end of the test section by fitting flange 17 bolts. The rear end of the test section is connected to two return air inlets 13 by round flange 20 bolts. The airflow regulating valve 12 at each return air inlet 13 is supported by bracket A16. The height of bracket A16 can be adjusted by rotating the thread. The rear end of the airflow regulating valve 12 is connected to the bend 14 by round flange 20 bolts. The other end of the bend 14 is connected to the return air pipeline of the test bench. The measuring tube 15 is welded on the top of the bend 14 to measure the airflow parameters at the return air inlet 13.

[0029] The specific control procedure during the experiment is as follows: Dual airflow drive control: Two sets of fans correspond to two flow channels respectively, independently driving the gas flow in the corresponding flow channel to ensure that the airflow velocity meets the requirements and avoids the mixing of airflows on the canopy surface, laying the foundation for spanwise temperature regulation. Transverse temperature regulation: The control system employs independent decoupled control of the valve positions of the liquid nitrogen evaporator 6 and the power of the electric furnace 7 corresponding to the four flow channels, with each channel equipped with a set of PID controllers. During heating, if the temperature of a certain zone is higher than that of other zones, the power of the electric furnace 7 in the corresponding flow channel is reduced; if the temperature of a certain zone is lower than that of other zones, the power of the electric furnace 7 in the corresponding flow channel is increased. During cooling, if the temperature of a certain zone is higher than that of other zones, the opening of the valve position of the liquid nitrogen evaporator 6 in the corresponding flow channel is increased; if the temperature of a certain zone is lower than that of other zones, the opening of the valve position of the liquid nitrogen evaporator 6 in the corresponding flow channel is decreased, ensuring the uniformity of the transverse temperature field. Forward temperature gradient adjustment: Two airflow regulating valves 12 are arranged side by side along the spanwise direction. The left airflow regulating valve adjusts the forward temperature gradient of canopy zones 1 and 2, and the right airflow regulating valve adjusts the forward temperature gradient of canopy zones 3 and 4. If the forward temperature gradient meets the requirements, the valve plate 22 remains centered. When heating, if the front temperature is higher than the rear temperature, the valve plate rotates upward; if the front temperature is lower than the rear temperature, the valve plate rotates downward. When cooling, if the front temperature is lower than the rear temperature, the valve plate rotates upward; if the front temperature is higher than the rear temperature, the valve plate rotates downward. The rotation angle is adjusted in real time according to the temperature difference between the front and rear ends. Joint control: Through the coordinated operation of four-channel independent temperature control and dual airflow regulating valve zone regulation, the uniformity of the spanwise temperature field and the directional temperature gradient of the canopy surface are simultaneously satisfied.

[0030] Example 1, see appendix for further details. Figure 3 ,like Figure 3As shown, in this implementation case, the air inlets 1 of the two fan transition sections 21 are bolted to the air outlets of the two sets of fans via flanges. Measuring tubes 15 are welded to the top of each fan transition section 21 to measure parameters such as airflow velocity and temperature at the air inlets 1. The other end of the fan transition section 21 is bolted to a short tee 2 via a round flange 20. The short tee 2 divides the pipeline into upper and lower layers. The short tee 2 is bolted to the cold circuit valve 3 and the hot circuit valve 4, and the cold circuit valve 3 and the hot circuit valve 4 are bolted to the long tee 5 via round flanges 20. The upper and lower layers each branch out into four paths via a long tee joint 5. The upper four paths are sequentially connected to one end of the electric furnace 7 and the rhomboid tube 8, respectively. The long tee joint 5 is bolted to the electric furnace 7 via a round flange 20, and the electric furnace 7 is bolted to the rhomboid tube 8. The lower four paths are sequentially connected to one end of the liquid nitrogen evaporator 6 and the rhomboid tube 8, respectively. The long tee joint 5 is bolted to the liquid nitrogen evaporator 6, and the liquid nitrogen evaporator 6 is bolted to the rhomboid tube 8 via a round flange 20. The other end of the eight rhomboid tubes 8 is nested within the rectifying section 9. When the high and low temperature circulating airflow causes thermal expansion and contraction in the pipeline, the rhomboid tubes 8 can freely expand and contract within the rectifying section 9 to achieve compensation. Three baffles 10 are welded side by side within the rectifying section 9, forming four flow channels. A measuring tube 15 is welded above each flow channel to measure parameters such as the flow velocity and temperature of each flow channel. The rhomboid tube 8 and the rectifying section 9 are joined by a bracket B18, the height of which can be adjusted by rotating the screw thread. The liquid nitrogen evaporator 6 and the electric furnace 7 are supported by a bracket C19, the height of which can be adjusted by rotating the screw thread. The other end of the rectifying section 9 is connected to the front end of the test section and fixed with bolts via a fitting flange 17. Two return air inlets 13 are each equipped with an airflow regulating valve 12, which is bolted to the rear end of the test section via a round flange 20. The airflow regulating valve 12 is supported by a bracket A16, the height of which can be adjusted by rotating the screw thread. The rear end of the airflow regulating valve 12 is connected to a bend 14, which is bolted to the round flange 20. The other end of the bend 14 is connected to the return air duct of the test bench. Measuring tubes 15 are welded to the top of the bend 14 to measure parameters such as airflow velocity and temperature at the return air inlet 13.

[0031] like Figure 2 , Figure 3 As shown, the specific control method during the experiment is as follows: a) Each of the two sets of fans corresponds to two flow channels. Each set of fans independently drives the gas flow in the corresponding flow channel to ensure that the gas in the flow channel has a sufficiently high flow velocity, and further ensures that the airflow in each flow channel does not mix when it flows over the surface of the canopy, thereby achieving temperature field regulation along the span of the canopy. b) Independently decouple the airflow temperature in the four flow channels, and set a separate PID control for the liquid nitrogen evaporator 6 valve position and electric furnace 7 power corresponding to each flow channel to realize independent control and adjustment of the temperature of each zone along the canopy. c) When the canopy needs to be heated, the control system controls the cold circuit valve 3 to close and the hot circuit valve 4 to open. According to the temperature load control given curve, the system compares the temperature measurement feedback value and the given value in real time. Through PID control, the system automatically adjusts the output power of the electric furnace 7 to heat the airflow, which flows over the surface of the canopy to heat it. When the canopy needs to be cooled, the control system controls the cold circuit valve 3 to open and the hot circuit valve 4 to close. According to the temperature load control given curve, the system compares the temperature measurement feedback value and the given value in real time. Through PID control, the system automatically adjusts the valve opening of the liquid nitrogen evaporator 6 to cool the airflow, which flows over the surface of the canopy to cool it. d) such as Figure 7 As shown, in the rectifier section 9, the airflow in channels 1 (25), 2 (26), 3 (27), and 4 (28) flows from end A to end B, and then flows to end C through sections 1 (29), 2 (30), 3 (31), and 4 (32) on the surface of the canopy 24, respectively. Spanning temperature field regulation includes the following four typical cases: Scenario 1: When heating the canopy, the airflow is hot. If the temperature of a certain zone is higher than that of other zones, without loss of generality, assuming that the temperature of zone 2 (30) is higher than that of zone 1 (29), zone 3 (31), and zone 4 (32), the output power of the electric furnace 7 corresponding to flow channel 26 is reduced by adjusting the control system. This reduces the airflow temperature in flow channel 26, thereby reducing the heating rate of zone 2 (30) and making its temperature consistent with that of other zones, thus ensuring the uniformity of the spanwise temperature field.

[0032] Scenario 2: When heating the canopy, the airflow is hot air. If the temperature of a certain zone is lower than that of other zones, without loss of generality, assuming that the temperature of zone 2 30 is lower than that of zone 1 29, zone 3 31, and zone 4 32, the output power of the electric furnace 7 corresponding to flow channel 26 is increased by adjusting the control system, thereby increasing the airflow temperature in flow channel 26, and thus increasing the heating rate of zone 2 30, so that its temperature is consistent with the temperature of other zones, ensuring the uniformity of the spanwise temperature field.

[0033] Scenario 3: To cool the canopy, the airflow is cold air. If the temperature of a certain zone is higher than that of other zones, without loss of generality, assuming that the temperature of zone 2 (30) is higher than that of zone 1 (29), zone 3 (31), and zone 4 (32), the control system adjusts and increases the valve opening of the liquid nitrogen evaporator 6 corresponding to flow channel 26, thereby reducing the airflow temperature in flow channel 26 and increasing the cooling rate of zone 2 (30) to make its temperature consistent with that of other zones, thus ensuring the uniformity of the spanwise temperature field.

[0034] Scenario 4: To cool the canopy, the airflow is cold air. If the temperature of a certain zone is lower than that of other zones, without loss of generality, assuming that the temperature of zone 2 (30) is lower than that of zone 1 (29), zone 3 (31), and zone 4 (32), the control system adjusts and reduces the valve opening of the liquid nitrogen evaporator 6 corresponding to flow channel 26, thereby increasing the airflow temperature in flow channel 26, and thus reducing the cooling rate of zone 2 (30) to make its temperature consistent with that of other zones, ensuring the uniformity of the spanwise temperature field.

[0035] e) such as Figures 8-10 As shown, the airflow enters from end A of the rectifier section 9, flows from end B (front end) to end C (rear end) through the flow channel formed by the canopy 24 and the deflector 33, and exchanges heat with the outer surface of the canopy 24 via convection. Then, it flows to the rear return air duct after being regulated by the airflow regulating valve 12. The directional temperature gradient regulation includes the following 5 typical cases: Scenario 1: If the heading temperature gradient meets the requirements, then valve plate 22 will be centered. Figure 8 As shown.

[0036] Scenario 2: Heating the cockpit canopy generates hot airflow. If, compared to the required directional temperature gradient, the temperature at end B (front) is higher and the temperature at end C (rear) is lower, then... Figure 9 As shown, the control system adjusts the valve plate 22 to rotate upward around the valve plate shaft 23, increasing the airflow near end C, thereby increasing the airflow velocity at end C, which in turn increases the convective heat exchange between the airflow and end C, improving the temperature rise rate at end C, and ensuring that the directional temperature gradient meets the requirements. The rotation angle θ1 is adjusted in real time according to the temperature conditions at ends B and C.

[0037] Scenario 3: Heating the cockpit canopy generates hot airflow. If, compared to the required directional temperature gradient, the temperature at end B (front) is lower and the temperature at end C (rear) is higher, then... Figure 10 As shown, the control system adjusts the valve plate 22 to rotate downwards around the valve plate shaft 23, reducing the airflow near end C, thereby reducing the airflow velocity at end C, which in turn reduces the convective heat exchange between the airflow and end C, lowers the temperature rise rate at end C, and ensures that the directional temperature gradient meets the requirements. The rotation angle θ2 is adjusted in real time according to the temperature conditions at ends B and C.

[0038] Scenario 4: To cool the cockpit canopy, the airflow is cold. If, compared to the required directional temperature gradient, the temperature at end B (front) is lower and the temperature at end C (rear) is higher, then... Figure 9As shown, the control system adjusts the valve plate 22 to rotate upward around the valve plate shaft 23, increasing the airflow near end C, thereby increasing the airflow velocity at end C, which in turn increases the convective heat exchange between the airflow and end C, improving the cooling rate at end C and ensuring that the directional temperature gradient meets the requirements. The rotation angle θ1 is adjusted in real time according to the temperature conditions at ends B and C.

[0039] Scenario 5: To cool the cockpit canopy, the airflow is cold. If, compared to the required directional temperature gradient, the temperature at end B (front) is higher and the temperature at end C (rear) is lower, then... Figure 10 As shown, the control system adjusts the valve plate 22 to rotate downwards around the valve plate shaft 23, reducing the airflow near end C, thereby reducing the airflow velocity at end C, which in turn reduces the convective heat exchange between the airflow and end C, lowers the cooling rate at end C, and ensures that the directional temperature gradient meets the requirements. The rotation angle θ2 is adjusted in real time according to the temperature conditions at ends B and C.

[0040] f) such as Figure 7 As shown, two airflow regulating valves 12 are arranged side-by-side along the spanwise direction. The airflow regulating valve 12 on the left spanwise direction regulates the directional temperature gradient of section 1 29 and section 2 30 of the canopy 24 (according to actual measurements, the directional temperature gradients of section 1 29 and section 2 30 are basically similar and change synchronously, therefore the directional temperature gradients of section 1 29 and section 2 30 are regulated by the same airflow regulating valve 12); the airflow regulating valve 12 on the right spanwise direction regulates the directional temperature gradient of section 3 31 and section 4 32 of the canopy 24 (according to actual measurements, the directional temperature gradients of section 3 31 and section 4 32 are basically similar and change synchronously, therefore the directional temperature gradients of section 3 31 and section 4 32 are regulated by the same airflow regulating valve 12).

[0041] g) such as Figure 7 As shown, based on the independent decoupling control of the four-channel airflow temperature and the joint control of the dual airflow regulating valve 12 driven by the corresponding dual air volume, the spanwise and yaw-wise distribution of the surface temperature field of the canopy 24 can be coordinated and controlled, while meeting the requirements of spanwise temperature field uniformity and yaw-wise temperature gradient.

[0042] Without loss of generality, the following typical cases are selected to illustrate the joint control and regulation process of the temperature field of the canopy 24: Typical case: The cockpit canopy was heated, and the temperature in zone 2 (30°C) was higher than in other zones. Compared with the required heading temperature gradient, the temperature at point B was lower and the temperature at point C was higher.

[0043] Joint control and regulation process: a) By adjusting the control system to reduce the output power of the electric furnace 7 corresponding to the No. 2 flow channel 26, the airflow temperature in the No. 2 flow channel 26 is reduced, thereby reducing the heating rate of the No. 2 partition 30 and making its temperature consistent with the temperature of other partitions, thus ensuring the uniformity of the spanwise temperature field. b) By adjusting the valve plate 22 of the airflow regulating valve 12 corresponding to the 2nd partition 30 through the control system, rotate the valve plate 22 downward around the valve plate pivot 23 (the valve plate 22 of the other airflow regulating valve 12 remains stationary), reduce the airflow near the C end, thereby reducing the airflow velocity at the C end, and thus reducing the convective heat exchange between the airflow and the C end, reducing the temperature rise rate at the C end, and ensuring that the heading temperature gradient meets the requirements. The rotation angle θ2 is controlled and adjusted in real time according to the temperature conditions at the B end and the C end.

[0044] The above detailed embodiments are a description of the present invention. It should not be considered that the specific embodiments of the present invention are limited to these descriptions. For those skilled in the art, several simple deductions and substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the protection scope of the present invention.

Claims

1. A dual-airflow driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopies, characterized in that, It includes an air inlet (1), a short tee (2), a cold circuit valve (3), a hot circuit valve (4), a long tee (5), a liquid nitrogen evaporator (6), an electric furnace (7), a rhomboid tube (8), a rectifier section (9), a baffle plate (10), a test section (11), an airflow regulating valve (12), a return air inlet (13), and a control system; the two air inlets (1) are respectively connected to the air outlets of two sets of fans to form a dual airflow drive structure; each air inlet (1) is divided into an upper hot circuit and a lower cold circuit through a short tee (2), the hot circuit is controlled by the hot circuit valve (4), and the cold circuit is controlled by the cold circuit valve (3); Each group of hot and cold paths is divided into two branches by a long three-way valve (5). The hot path branch is equipped with an electric furnace (7), and the cold path branch is equipped with a liquid nitrogen evaporator (6), forming a total of 4 electric furnaces (7) and 4 liquid nitrogen evaporators (6), constituting eight energy units. The rectifier section (9) is divided into 4 flow channels by a partition (10), and the 4 energy units correspond one-to-one with the 4 flow channels. After the airflow is regulated by the energy unit temperature, it is introduced into the rectifier section (9) through a rhomboid tube (8). The rhomboid tube (8) is nested in the rectifier section (9) and can extend and retract freely. The rectifier section (9) is connected to the test section (11). The test section (11) has a return air port (13) at the rear end, and an airflow regulating valve (12) is configured at the return air port (13). The control system controls the energy units and the airflow regulating valve (12) to achieve joint regulation of the spanwise temperature and heading temperature of the circulating airflow.

2. The dual-airflow driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopy according to claim 1, characterized in that, The four sets of liquid nitrogen evaporators (6) and the four sets of electric furnaces (7) are arranged side by side along the longitudinal direction, and the liquid nitrogen evaporators (6) and the electric furnaces (7) facing each other vertically constitute a group of energy units, corresponding to one flow channel of the rectifier section (9).

3. The aircraft cockpit canopy high and low temperature test dual-airflow driven eight-energy-unit control device according to claim 2, characterized in that, The rectifying section (9) is a square tube structure with three partitions (10) welded in parallel along the longitudinal direction inside, which divide the flow channel inside the rectifying section (9) into four independent flow channels. Each flow channel is equipped with a measuring tube (15) above it.

4. The aircraft cockpit canopy high and low temperature test dual-airflow driven eight-energy unit control device according to claim 1, characterized in that, One end of the rhomboid tube (8) is nested inside the rectifying section (9) and can freely expand and contract along the axial direction of the rectifying section (9) to compensate for the thermal expansion and contraction deformation of the flow channel.

5. The dual-airflow driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopy according to claim 1, characterized in that, The valve plate of the airflow regulating valve (12) is arranged along the longitudinal direction with the valve plate (23) rotating around the valve plate (23) vertically. The adjustment range is ±45 degrees. +45 degrees corresponds to the valve plate (22) being completely closed downwards, and -45 degrees corresponds to the valve plate (22) being completely closed upwards.

6. The dual-airflow driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopy according to claim 1, characterized in that, The control system configures a set of PID controllers for the valve position of the liquid nitrogen evaporator (6) and the power of the electric furnace (7) corresponding to each flow channel, so as to realize independent decoupled control of the temperature of the four flow channels.

7. The aircraft cockpit canopy high and low temperature test dual-airflow driven eight-energy unit control device according to claim 1, characterized in that, Two airflow regulating valves (12) are arranged side by side along the span direction. The left airflow regulating valve (12) regulates the heading temperature gradient of the canopy (24) in section 1 (29) and section 2 (30), and the right airflow regulating valve (12) regulates the heading temperature gradient of section 3 (31) and section 4 (32).

8. The dual-airflow driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopy according to claim 1, characterized in that, The control system achieves synchronous control of the spanwise temperature field uniformity and the heading temperature gradient of the canopy (24) through the coordinated cooperation of independent temperature control of four flow channels and zoned adjustment of dual airflow regulating valves (12).

9. The dual-airflow driven eight-energy-unit control device for high and low temperature testing of aircraft cockpit canopy according to claim 1, characterized in that, The hot circuit valve (4) and the cold circuit valve (3) are open-close control valves. Under heating conditions, the cold circuit valve (3) is closed and the hot circuit valve (4) is open. Under cooling conditions, the cold circuit valve (3) is open and the hot circuit valve (4) is closed.

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