A device and method for testing a nose-tip ablative shape with an attack angle

Abstract

The application discloses a device and a method for testing a model with an attack angle and ablation shape, and the device comprises an arc heater, a mixing chamber, a supersonic nozzle, a test model, a variable attack angle device, a camera temperature measuring device and a support; the arc heater, the mixing chamber and the supersonic nozzle are sequentially connected; the variable attack angle device is installed on the support; the test model is installed on the variable attack angle device and located at the outlet end of the supersonic nozzle; and the camera temperature measuring device is arranged at a position for shooting the test model. The application aims to meet the simulation requirement of the test of the model with the attack angle and the ablation shape.

Description

Technical Field

[0001] This invention belongs to the field of ground-based simulated aerodynamic thermal testing technology for aircraft, and particularly relates to a test device and test method for ablation profile with angle of attack end. Background Technology

[0002] During the reentry of hypersonic vehicles, the thermal environment at the vehicle's nose is extremely harsh, and the nose's shape undergoes drastic changes due to ablation, significantly impacting the vehicle's aerodynamic and motion control characteristics. Traditional inertial ballistic reentry vehicles often employ spin-stabilized control methods, typically using low angles of attack during ballistic flight, and the ablation morphology on the vehicle's surface is relatively uniform under spin. Newer vehicles are diversifying their reentry trajectories, employing high angle-of-attack maneuvers, gliding, and cruise trajectories, which are more advantageous for penetrating defenses.

[0003] The most significant characteristic of the trajectory of the new hypersonic vehicle is its long-duration, angle-of-attack self-controlled flight. During this flight, the vehicle itself does not spin, and the asynchrony between the ablation shape changes of its windward and leeward sides severely affects the aerodynamic characteristics and control performance of the vehicle, and even threatens the safety and stability of the entire vehicle.

[0004] Boundary layer transition significantly affects the ablation profile and final shape of an aircraft, influenced by more than ten potential factors, including model angle of attack, wall temperature, wall roughness, boundary layer outer edge Mach number, incoming flow unit Reynolds number, velocity gradient, and pressure gradient. The constantly changing shape of the aircraft makes the boundary layer transition problem extremely complex, thus a complete theoretical framework has yet to be established, particularly regarding the impact of angle of attack on the ablation profile of the nose section.

[0005] As the main equipment for ground simulation test research on aerodynamic thermal protection, there is relatively little research on ablation shape test with angle of attack and boundary layer transition in the arc-heated flow field. Therefore, how to fully reproduce the thermal environment experienced by the end face with angle of attack during ground test, and further understand the difference in thermal environment between the windward and leeward sides, and provide ablation shape test data of the windward and leeward sides for end face thermal protection design, is of great significance for the precise thermal protection design of aircraft. Summary of the Invention

[0006] The technical problem solved by the present invention is to overcome the shortcomings of the prior art and provide a test device and test method for ablation profile with angle of attack end, which can meet the simulation requirements of ablation profile test with angle of attack.

[0007] To solve the above-mentioned technical problems, the present invention discloses a test device for ablation profile with angle of attack end, comprising: an arc heater, a mixing chamber, a supersonic nozzle, a test model, a variable angle of attack device, a camera temperature measuring device, and a support.

[0008] The electric arc heater, mixing chamber, and supersonic nozzle are connected in sequence;

[0009] The variable angle of attack device is mounted on the bracket;

[0010] The test model was mounted on the variable angle of attack device and located at the exit end of the supersonic nozzle.

[0011] The camera temperature measurement device is set at the location where the test model is captured.

[0012] In the above-mentioned ablation profile test device with angle of attack end, the variable angle of attack device includes: a water-cooled model device, a model support and fixing device, and a pneumatic angle of attack feeding device; wherein, the pneumatic angle of attack feeding device includes: a controller, a stepper motor, a universal joint, a cylinder, and a push rod.

[0013] The test model is connected to the water-cooled model device via threads;

[0014] One end of the water-cooled model device has an arc-shaped protrusion, and the model support and fixing device has an arc-shaped groove. The water-cooled model device is installed on the model support and fixing device, and the arc-shaped protrusion of the water-cooled model device is located in the arc-shaped groove of the model support and fixing device. A universal joint is provided between the arc-shaped protrusion and the arc-shaped groove to form a rotating pair.

[0015] The model support and fixing device is fixed to the ground by a bracket;

[0016] The controller is connected to the stepper motor, the stepper motor is connected to the cylinder, and the cylinder is connected to the push rod. During the test, the controller controls the stepper motor to work, which drives the cylinder to do work and push the push rod to move. The push rod pushes the water-cooled model device to rotate around the model support fixing device, thereby realizing the adjustment of the angle of attack of the test model, so that the test model can meet the simulation requirements of ablation shape test at different angles of attack. When the angle of attack of the test model is adjusted to the correct position, the universal joint is locked to support the water-cooled model device and the test model, ensuring the stability of the entire device throughout the entire test heating process.

[0017] In the above-mentioned test device for ablation of the end with angle of attack, the water-cooled model device uses high-pressure water cooling to protect the test model.

[0018] In the aforementioned test device for ablation of the test model with an angle of attack, the variable angle of attack device adjusts the angle of attack of the test model according to the test requirements. The high-temperature and high-pressure air heated by the arc heater is accelerated by the supersonic nozzle and ablation occurs with the test model. Combined with the supersonic free jet test, the thermal environment during the flight of the aircraft tip is simulated.

[0019] In the above-mentioned ablation shape test device with angle of attack end, the camera temperature measurement device is used to capture and measure the deformation and temperature of the test model during the experiment, and obtain the deformation, temperature and time change curves.

[0020] Accordingly, this invention discloses a test method based on an ablation profile test device with an angle-of-attack end, comprising:

[0021] Based on the test conditions and test model dimensions, determine the dimensions of the supersonic nozzle and estimate the operating parameters of the arc heater.

[0022] The ablation flow field was debugged, the pressure distribution and heat flow distribution on the windward and leeward sides of the test model were measured, and the final operating parameters of the electric arc heater were determined based on the measurement results.

[0023] Install the test model and adjust the angle of attack of the test model to the required test state using the variable angle of attack device;

[0024] A variable angle of attack ablation shape test was conducted, and the deformation and temperature changes of the test model during the experiment were measured and recorded by a camera temperature measuring device to obtain the deformation, temperature and time change curves.

[0025] The present invention has the following advantages:

[0026] This invention discloses a test device for ablation profile with angle of attack. During the test, the angle of attack of the test model can be adjusted by a variable angle of attack device according to the test requirements to meet the simulation requirements of ablation profile with angle of attack. At the same time, after the angle of attack is adjusted to the correct position, the variable angle of attack device supports the test model to ensure the stability of the entire device during the entire test heating process. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of a test device for ablation of an end with an angle of attack in an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram of a variable angle of attack device according to an embodiment of the present invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments disclosed in the present invention will be described in further detail below with reference to the accompanying drawings.

[0030] One of the core ideas of this invention is: relying on an electric arc heater and closely combining the requirements of end-point ablation shape test with angle of attack, innovatively developing an end-point ablation shape test device with angle of attack, and conducting end-point ablation shape test research based on ground equipment (electric arc heater, supersonic nozzle, etc.), which has many advantages such as short test preparation cycle, high equipment precision, and real adjustable test components, and can be widely used in end-point heat protection material anti-ablation test research.

[0031] like Figure 1 In this embodiment, the ablation profile testing device with angle of attack end includes: an arc heater 1, a mixing chamber 2, a supersonic nozzle 3, a test model 4, a variable angle of attack device 5, a camera temperature measuring device 6, and a support 10. The arc heater 1, mixing chamber 2, and supersonic nozzle 3 are connected sequentially; the variable angle of attack device 5 is mounted on the support 10; the test model 4 is mounted on the variable angle of attack device 5 and located at the outlet end of the supersonic nozzle 3; the camera temperature measuring device 6 is positioned at the location where the test model 4 is captured.

[0032] In this embodiment, as Figure 2 The variable angle of attack device 5 specifically includes: a water-cooled model device 7, a model support and fixing device 8, and a pneumatic angle of attack feeding device 9; the pneumatic angle of attack feeding device 9 includes: a controller, a stepper motor, a universal joint, a cylinder 11, and a push rod 12. The test model 4 is connected to the water-cooled model device 7 via threads. One end of the water-cooled model device 7 has an arc-shaped protrusion, and the model support and fixing device 8 has an arc-shaped groove. The water-cooled model device 7 is mounted on the model support and fixing device 8, with the arc-shaped protrusion of the water-cooled model device 7 located within the arc-shaped groove of the model support and fixing device 8. A universal joint is provided between the arc-shaped protrusion and the arc-shaped groove, forming a rotating pair. The model support and fixing device 8 is fixed to the ground by a bracket 10. The controller is connected to the stepper motor, the stepper motor is connected to the cylinder 11, and the cylinder 11 is connected to the push rod 12. During the test, the controller controls the stepper motor to work, which drives the cylinder 11 to do work and push the push rod 12 to move. The push rod 12 pushes the water-cooled model device 7 to rotate around the model support fixing device 8, thereby realizing the adjustment of the angle of attack of the test model 4, so that the test model 4 meets the simulation requirements of ablation shape test at different angles of attack. When the angle of attack of the test model 4 is adjusted to the correct position, the universal joint is locked to support the water-cooled model device 7 and the test model 4, ensuring the stability of the entire device during the entire test heating process.

[0033] Preferably, the water-cooled model device 7 uses high-pressure water cooling to protect the test model 4.

[0034] Preferably, the variable angle of attack device 5 adjusts the angle of attack of the test model 4 according to the test requirements. The high-temperature and high-pressure air heated by the arc heater 1 is accelerated by the supersonic nozzle 3 and undergoes ablation with the test model 4. Combined with the supersonic free jet test, the thermal environment during the flight process of the aircraft tip is simulated.

[0035] Preferably, the camera temperature measuring device 6 is used to capture the deformation and temperature of the test model 4 during the measurement experiment, and obtain the deformation and temperature and time change curves.

[0036] Preferably, test model 4 can specifically refer to the end ablation shape model.

[0037] In summary, this invention discloses a test device for ablation profiles at an angle of attack. High-temperature air generated by an arc heater is used to propel an ablation profile model at a specific angle of attack into a high-temperature flow field via a variable angle-of-attack device. The ablation profile model is then tested, and its thermal resistance performance is analyzed. This invention innovatively develops a test technology for ablation profiles at an angle of attack using supersonic free-jet testing technology on a ground-based arc heating device and a high-precision variable angle-of-attack device. The test results for ablation profiles at an angle of attack are obtained, providing experimental data for ablation profile thermal protection design. The solution described in this invention can conduct ground-based testing and evaluation of the nose section of an aircraft, meeting the requirements for ground simulation of the thermal environment at the nose of an aircraft with an angle of attack, and providing experimental data for ablation profile thermal protection design.

[0038] Based on the above embodiments, the present invention also discloses a test method based on the above-mentioned ablation profile test device with angle of attack end, comprising: determining the size of the supersonic nozzle 3 according to the test state requirements and the size of the test model 4, and estimating the operating parameters of the arc heater 1; performing ablation flow field adjustment, measuring the pressure distribution and heat flow distribution on the windward and leeward sides of the test model 4, and determining the final operating parameters of the arc heater 1 based on the measurement results; installing the test model 4, and adjusting the angle of attack of the test model 4 to the test state requirements through the variable angle of attack device 5; conducting a variable angle of attack end ablation profile test, and measuring and recording the deformation and temperature change of the test model 4 during the experiment through the camera temperature measuring device 6, and obtaining the deformation versus temperature and time change curves.

[0039] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

[0040] The contents not described in detail in this specification are common knowledge to those skilled in the art.

Claims

1. A test device for ablation profile with an angle of attack end, characterized in that, include: Arc heater (1), mixing chamber (2), supersonic nozzle (3), test model (4), variable angle of attack device (5), camera temperature measuring device (6) and support (10); The electric arc heater (1), the mixing chamber (2), and the supersonic nozzle (3) are connected in sequence; The variable angle of attack device (5) is mounted on the bracket (10); The test model (4) is installed on the variable angle of attack device (5) and located at the outlet end of the supersonic nozzle (3); The camera temperature measuring device (6) is set at the location where the test model (4) is photographed; The experimental model (4) specifically refers to the ablation shape model of the end; The variable angle of attack device (5) includes: a water-cooled model device (7), a model support and fixing device (8), and a pneumatic angle of attack feeding device (9); wherein, the pneumatic angle of attack feeding device (9) includes: a controller, a stepper motor, a universal joint, a cylinder (11), and a push rod (12); wherein, the test model (4) is connected to the water-cooled model device (7) by a thread; one end of the water-cooled model device (7) is an arc-shaped protrusion, and an arc-shaped groove is provided on the model support and fixing device (8); the water-cooled model device (7) is installed on the model support and fixing device (8), the arc-shaped protrusion of the water-cooled model device (7) is located in the arc-shaped groove of the model support and fixing device (8), and a universal joint is provided between the arc-shaped protrusion and the arc-shaped groove to form a rotating pair; The model support and fixing device (8) is fixed on the ground by the bracket (10); the controller is connected to the stepper motor, the stepper motor is connected to the cylinder (11), and the cylinder (11) is connected to the push rod (12); during the test, the controller controls the stepper motor to work, drives the cylinder (11) to do work, pushes the push rod (12) to move, and the push rod (12) pushes the water-cooled model device (7) to rotate around the model support and fixing device (8), thereby realizing the adjustment of the angle of attack of the test model (4), so that the test model (4) meets the requirements of ablation shape test simulation of different angles of attack; when the angle of attack of the test model (4) is adjusted to the position, the universal joint is locked to support the water-cooled model device (7) and the test model (4), ensuring the stability of the entire device during the entire test heating process.

2. The ablation profile testing device with angle of attack end according to claim 1, characterized in that, The water-cooled model device (7) is cooled by high-pressure water, which serves to cool and protect the test model (4).

3. The ablation profile testing device with angle of attack end according to claim 1, characterized in that, The variable angle of attack device (5) adjusts the angle of attack of the test model (4) according to the test requirements. The high temperature and high pressure air heated by the arc heater (1) is accelerated by the supersonic nozzle (3) and ablation occurs with the test model (4). Combined with the supersonic free jet test, the thermal environment during the flight process of the aircraft tip is simulated.

4. The ablation profile testing device with angle of attack end according to claim 3, characterized in that, The camera temperature measuring device (6) is used to photograph the deformation and temperature of the test model (4) during the measurement experiment, and obtain the curves of deformation, temperature and time.

5. A test method based on the ablation profile test device with angle of attack end as described in claim 1, characterized in that, include: Based on the test conditions and the dimensions of the test model (4), the dimensions of the supersonic nozzle (3) are determined, and the operating parameters of the arc heater (1) are estimated. The ablation flow field was adjusted, the pressure distribution and heat flow distribution on the windward and leeward sides of the test model (4) were measured, and the final operating parameters of the electric arc heater (1) were determined based on the measurement results. Install the test model (4) and adjust the angle of attack of the test model (4) to the test state requirements through the variable angle of attack device (5); A variable angle of attack end ablation shape test was conducted, and the deformation and temperature change of the test model (4) during the experiment were measured and recorded by a camera temperature measuring device (6) to obtain the deformation and temperature and time change curves.

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