Effective Thermal Conductivity and Heat Transfer Characteristics for a Series of Lightweight Lattice Core Sandwich Panels

The body-centered cubic lattice sandwich panels have superior mechanical performance, and current works only focus on their mechanical performance. The effective thermal conductivity and heat transfer characteristics for a series of body-centered cubic lattice sandwich panel were explored by theoretical analysis and numerical modeling. It is revealed that through the rational design of the geometry, the relative density is modulated to be within 5%, suggesting the excellent lightweight character is obtainable. The numerical simulation agrees well with the theoretical predictions, indicating the theoretical expressions can well predict the effective thermal conductivity with the consideration of the heat conduction and cavity radiation. The effective thermal conductivity is within 3.5 W/(m.degrees C) which is much lower than that of the constituent, indicating the design of the lattice core sandwich panel reduces the effective thermal conductivity as well as gives the lightweight design. It is revealed that the sandwich panel PY always presents the low relative density and high insulation efficiency. The results obtained in this work provide a basic reference to the parameter selection of the body-centered cubic lattice core sandwich panels for the potential applications in hot structures.