Cloaking a concentrator in thermal conduction via topology optimization

The simultaneous cloaking and concentrating of heat flux is achieved through topology optimization based on a covariance matrix adaptation evolution strategy by formulating the optimization problem of improving two different objective functions. The topology-optimized thermal cloak-concentrator realizes excellent bi-functionality (i.e., cloaking and concentrating) despite having a simple composition, and structural characteristics needed for simultaneous cloaking and concentrating are revealed adopting a level set method with clear structural interfaces. Moreover, a thermal cloak-concentrator that is robust against fluctuations of thermal conductivity is designed by improving a fitness incorporating multiple objective functions under various thermal conductivities. (C) 2020 Elsevier Ltd. All rights reserved.