A method for thermal conductivity analysis of airgel insulation layer in monolithic tps

Abstract

The invention discloses a method for analyzing the thermal conductivity of an aerogel thermal insulation layer in a monolithic TPS. The method comprises: measuring thermophysical parameters of an aerogel thermal insulation layer at different temperatures under normal pressure; drawing a relationship curve between the thermal conductivity of the aerogel thermal insulation layer and the temperature,and establishing thermal conductivity and temperature correlations having correction coefficients and used for each segment of the curve; carrying out electric arc tunnel test on a monolithic TPS under different air pressure conditions, surveying and mapping the surface temperature increase curve of the surface temperature of an outer thermal insulation surface plate along with the time change, and surveying and mapping the first temperature increase curve of the back surface of an inner auxiliary surface plate or a metal bearing plate; carrying out simulation calculation according to the test conditions of the electric arc tunnel test, and drawing the second temperature increase curve of the back surface of the metal bearing plate; and comparing the first temperature increase curve drawnsurveyed and mapped according to the electric arc tunnel test to the second temperature increase curve drawn according to the simulation calculation under the same air pressure condition so as to adjust the thermal conductivity of the aerogel thermal insulation layer by adjusting the correction coefficient. With the method of the present invention, the accurate thermal conductivity of the aerogelthermal insulation layer can be obtained.

Description

technical field [0001] The invention relates to the technical field of thermal protection structures. More specifically, it relates to a thermal conductivity analysis method of an airgel thermal insulation layer in a monolithic TPS. Background technique [0002] Hypersonic vehicles fly in the atmosphere at a high Mach number for a long time, and thermal protection design is required. In order to ensure that the design of the thermal protection scheme meets the requirements of the overall indicators, it is necessary to carry out the thickness and weight analysis of the thermal protection layer according to the thermal physical parameters of the thermal protection material. like figure 1 As shown, the integral TPS (thermal protection structure) includes an outer heat-resistant panel 1, an airgel insulation layer 2, an inner auxiliary panel 3, an adhesive layer 4 and a metal carrier plate 5, wherein the airgel insulation layer 2 includes Rigid insulating material 21 and stit...

AI Technical Summary

Problems solved by technology

Since the material of the airgel heat insulation layer 2 is a porous translucent medium, there are multiple heat transfer modes such as transmission, radiation, gas heat conduction, and solid heat conduction, and the heat transfer characteristics are greatly affected by low pressure phenomena. The measurement of the thermal conductivity of thermal layer 2 poses great difficulties

The thermal conductivity of the composite material of the airgel insulation layer 2 is extremely low, about 0.02W / (m.k) at room temperature and about 0.08W / (m.k) at high temperature. The influence of traditional steady-state method / transient method measurement error on thermal conductivity Correspondingly, it brings great difficulties to the design and evaluation of thermal protection structures

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