Research on insulation properties of high-speed aircraft lightweight heat-resistant materials in high-temperature environment

Lightweight materials are widely used in missiles and other high-speed aircraft for thermal protection. As the lightweight heat-resistant materials differ in density, quality, technology, production batches, and other aspects, their individual discrete thermal conductivities, provided by the manufacturer, are normally quite different from the actual values. In this paper, in order to provide reliable thermal conductivities suitable for accurate numerical simulation, a device was established for measuring high-temperature thermal conductivity of lightweight heat-resistant materials. Moreover, by using the nonlinear relationship between the temperature and thermal conductivity obtained by experimental methods, the heat insulation effect of lightweight high-temperature heat-resistant ceramic materials was simulated numerically by the finite element method. The heat-resistant materials mentioned above were also tested by the transient aerodynamic heating simulation experimental system, and a comparison between the results of the calculation and experiment carried out. This revealed satisfactory agreement between calculation and experiment, which indicates that calculated results with greater accuracy could be obtained by using the nonlinear relationship between temperature and the measured thermal conductivity. The study lays a solid base for the replacement of costly transient aerodynamic heating simulation testing by numerical simulation.