RESEARCH ON HEAT-SHIELDING PROPERTIES OF SUPERALLOY HONEYCOMB PANEL FOR NON-LINEAR HIGH TEMPERATURE ENVIRONMENT

The heat-shielding characteristics of metallic honeycomb panel structure (MTPS) in high temperature environments are very important parameters for thermal protection design of high-speed aircrafts. Using the self-developed transient aerodynamic heating simulation system designed for high-speed aircrafts, the heat-shielding performance of MTPS in the non-linear high temperature environment up to 800℃ was experimentally investigated. The heat-transfer characteristics of MTPS at transient and steady states, and the heat insulation effects at various temperatures, were obtained. Also, by carefully considering the multiple heat exchange including the radiation among the inside honeycomb walls, the heat transfer of the metal structure and the heat transfer of the air within the honeycomb cavity, a three dimensional finite element model was established to simulate the heat-shielding performance of the honeycomb panels. The numerical simulations agree well with the experimental results, verifying the correctness and effectiveness of the numerical simulation method. The good agreements also confirm the feasibility of substituting expensive air thermal simulation testing using numerical simulation. Some other key issues, such as heat shielding efficiency variation of the MTPS in complex non-linear high temperature environment, the relationship among the heat shielding efficiency, the change speed of front surface temperature and selection of emissivity for the MTPS' surface, were also discussed in this work, which provide important references for the heat-shielding of MTPS to be used in high-speed crafts.