Diffusion Approximation and Metamaterial Design of Thermal Radiation

Abstract

AbstractIn recent years, there has been a growing interest in the design and application of metamaterials, especially in achieving unique physical properties.Transformation theory, as a powerful tool, has been actively employed not only in the realm of wave systems, such as electromagnetic waves but also in diffusion systems, including thermal diffusion, mass diffusion, and plasmonic diffusion.This chapter delves into the forefront of metamaterial design, emphasizing the significance of radiative heat transfer in this field and how the clever integration of transformation theory with the Rosseland diffusion approximation opens up innovative avenues for metamaterial design. We will also focus on novel approaches to achieving thermal camouflage, laying a solid foundation for future technological developments. Since the Rosseland diffusion approximation primarily addresses far-field problems, this article will further introduce a range of different types of metamaterials, covering near-field and far-field applications to cater to various domain-specific requirements. Special attention will be given to applications in radiative cooling and thermophotovoltaic systems, exploring how metamaterial design can enhance the performance of these systems. Finally, we will summarize the key findings of this article, encompassing other metamaterial designs relevant to radiative heat transfer and thermal conduction. We will also propose some promising directions for future research, offering a glimpse into the potential impact of metamaterials in the fields of science and engineering.