Optimal design of a bilayer for the highest thermal resistance: A lesson learned from the shells of snails from hydrothermal extreme environment

TL;DR

This paper theoretically analyzes how the stacking sequence and layer thicknesses in a bilayer structure influence its thermal resistance, inspired by snail shells from extreme environments, providing design insights for thermal barriers.

Contribution

It introduces a semi-analytical model to optimize bilayer design for maximum thermal resistance based on biological inspiration.

Findings

Stacking sequence significantly affects thermal resistance.

Optimal layer thickness ratios enhance thermal performance.

Biological structures inform engineering thermal barrier design.

Abstract

Inspired by the unique design of the shells of snails inhabiting the deep-sea hydrothermal environment, here we theoretically study the temperature response of a bilayer to an external thermal impulse. A semi-analytical solution to the temperature field in the bilayer is obtained, allowing us to assess the peak temperature that occurs on the inner wall as a quantitative indicator of the thermal resistance of the bilayer. The structural determining factors of the thermal resistance of a bilayer are then investigated by examining the effects of the stacking sequence and volume fractions of the constitutive layers on the peak temperature on the inner wall. Our results indicate that the stacking sequence of the two layers in a bilayer, as well as their volume fractions, play important roles in determining the thermal resistance. For two layers with given materials, there exists an optimal stacking sequence and thickness ratio giving rise to the best thermal resistance. The results of our work not only account for the unique laminated design of the snail shells from hydrothermal environments but also provide practical guidelines for the design of multilayer thermal barriers in engineering.