High-temperature thermal radiation coefficient testing device and method for ablative heat-proof material

Abstract

The invention relates to a high-temperature thermal radiation coefficient testing device and method for an ablative heat-proof material. According to the device and the method, oxygen can be preventedfrom oxidizing the ablative heat-proof material in a test sample heating process, interference of pyrolysis gas for thermal radiation signals on the ablation surface of the material is eliminated, and accurate testing for high-temperature thermal radiation coefficients of the ablative heat-proof material is realized. An inert atmosphere purge system and an oxygen concentration sensor can be controlled online in real time according to air strength, real-time monitoring and control of oxygen concentration in the test sample heating environment are realized, surface state change caused by oxidation reaction of the ablative heat-proof material in a high-temperature environment is avoided, and a high-temperature and oxygen-poor real service environment of the material in a state close to an atmosphere reentry or near-space hypersonic flight can be constructed; real-time online control for the inert atmosphere purge system and a real-time monitoring system for test optical path infrared transmittance can be realized on the basis of the air strength, so that real-time monitoring and control for transmitting optical path transmittance of the thermal radiation signals of the test sample are realized, the absorption of the pyrolysis gas released by the ablative heat-proof material on the thermal radiation signals of the test sample can be effectively inhibited, and accuracy of a testingresult of the thermal radiation coefficients is guaranteed. The effective testing device and method can be provided for disclosing evolvement rules of normal spectral thermal radiation coefficients and normal full-wavelength thermal radiation coefficients of the ablative heat-proof material in the high-temperature service environment.

Description

technical field [0001] The invention relates to the field of thermal radiation coefficient testing of materials, in particular to a high-temperature thermal radiation coefficient testing device and testing method for ablation heat-resistant materials. The temperature range involved is from 200°C to 1000°C. The ablative heat-resistant materials involved refer to a class of solid materials represented by resin-based heat-resistant composite materials that overcome aerodynamic heating during aircraft reentry through complex physical and chemical processes such as pyrolysis carbonization and gas injection under the action of heat flow. . The thermal radiation coefficient involved is the material normal spectral thermal radiation coefficient and the normal full wavelength thermal radiation coefficient. Background technique [0002] The outer heat-resistant structure of atmospheric re-entry vehicles and near-space hypersonic vehicles usually generates high surface temperature du...

AI Technical Summary

Problems solved by technology

Different from conventional materials, this type of material has the following characteristics during the heating process: First, the surface state of the material is strongly affected by the oxygen content in the atmosphere. When the sample is heated in the air atmosphere, the material matrix is ​​completely oxidized, and an ablated carbon layer cannot be formed. The thermal radiation characteristic parameters of the material surface obtained by the test are very different from the thermal radiation characteristic parameters of the real atmospheric re-entry process, which has no reference value; in addition, in a vacuum or inert atmosphere environment, the material matrix undergoes a violent pyrolysis reaction when heated, releasing a large amount of heat. Decomposition gas, its main components are hydrocarbons such as methane, ethane, ethylene, acetylene, benzene, toluene, etc. These gas phase compounds have a strong absorption effect on infrared spectrum signals, which will seriously interfere with the test results of thermal emissivity of materials. Therefore, it is also impossible to test the high-temperature thermal radiation coefficient of ablation heat-resistant materials in a completely closed heating environment.

[0007] From the above analysis, it can be seen that the existing devices and methods for testing the thermal radiation coefficient of materials, especially the devices and methods for achieving high temperature on the surface of the sample, cannot complete the accurate test of the high-temperature thermal radiation coefficient of ablation heat-resistant materials.

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