Research on the thermal response characteristics of lightweight insulation structure with various shaped lattice units

Abstract

The study of heat transfer characteristics of various lattice structures is necessary for the lightweight design of lattice structures, which are basic units for integrated insulation-bearing structures in the hypersonic aircraft. In this work, the heat transfer characteristics of six representative volume elements based on single-cell are investigated by numerical and experimental methods. Two lightweight insulation structures are designed using the Gibson-Ashby and tetrakaidecahedron simple-cells, which exhibit superior insulation performance. The thermal response characteristics of two structures are comprehensively investigated. The end face area of the lattice unit significantly influences the insulation performance, with a small end face area leads to a good insulation performances. Compared to the tetrakaidecahedron configuration, the Gibson-Ashby configuration demonstrates a superior insulation performance. The inner wall temperature of the structure containing the Gibson-Ashby lattice unit is consistently lower than that of the structure containing the tetrakaidecahedron lattice unit. In the ground experiments, the maximum relative temperature difference between the inner wall surfaces of the tetrakaidecahedron lattice structure and the Gibson-Ashby lattice structure is 7.6 %, while in the flight experiments, it reaches 18 %. Through heat flux inversion, flight conditions were simulated, and the results show that the temperature on the inner wall surface, which is protected by the lightweight insulation structure, remained below 320 K while the outer wall temperature reaches a high value of 423.6 K. These conclusions provide important references for the lightweight design of aircraft insulation structures.