🤖 AI Summary
Existing topology optimization methods struggle to accurately model multidirectional mutual radiation effects, limiting performance improvements in radiative heat dissipation devices. This work proposes a density-based topology optimization framework that couples finite element heat conduction analysis with a radiative heat transfer model combining the zonal method and ray tracing. The approach explicitly accounts for mutual radiation during optimization and treats intermediate-density materials as participating media, thereby physically consistent modeling of radiative behavior at implicit boundaries. Notably, this is the first topology optimization method to employ ray tracing for precise modeling of mutual radiation, successfully generating high-performance radiative heat sinks and multilayer insulation structures unattainable by conventional approaches. The results demonstrate the critical influence of the balance between conduction and radiation on optimal configurations, with designs significantly outperforming existing solutions.
📝 Abstract
Thermal management is essential in space systems, where electronic devices must dissipate heat via radiative heat transfer. To achieve efficient designs of radiative cooling devices, structural optimization approaches such as topology optimization are required. While existing topology optimization methods have incorporated radiative heat transfer with certain simplifications, fully accounting for multidirectional mutual radiation remains challenging. To address this issue, this study proposes a density-based topology optimization method for conduction-radiation heat transfer problems that accounts for multidirectional mutual radiation. The proposed method integrates a zonal-method-based radiative heat transfer analysis incorporating a ray-tracing method into the finite element heat conduction analysis, capturing radiation effects during the optimization process. By treating the intermediate material densities that arise during the optimization as participating media, the proposed method enables a physically consistent evaluation of radiative heat transfer on implicitly represented structural boundaries. The analytical design sensitivities are derived using the adjoint method, and the accuracy is confirmed by the comparison with the numerical sensitivities obtained by the finite difference method. Numerical examples demonstrate the optimization of radiative heat sinks and radiation shields. The heat sink examples clarify how the balance between conduction and radiation governs the resulting designs, while the radiation shield examples produce multilayer insulation structures that are not obtained by conventional approaches.