Bragg Mirrors for Thermal Waves

• Published in: Energies
• Main Authors: Angela Camacho de la Rosa, David Becerril, María Guadalupe Gómez-Farfán, Raúl Esquivel-Sirvent
• Format: Article
• Language: English
• Published: MDPI AG 2021-11-01
• Subjects: Cattaneo-Vernotte; waves; Bragg
• Online Access: https://www.mdpi.com/1996-1073/14/22/7452

We present a numerical calculation of the heat transport in a Bragg mirror configuration made of materials that do not obey Fourier’s law of heat conduction. The Bragg mirror is made of materials that are described by the Cattaneo-Vernotte equation. By analyzing the Cattaneo-Vernotte equation’s solutions, we define the thermal wave surface impedance to design highly reflective thermal Bragg mirrors. Even for mirrors with a few layers, very high reflectance is achieved (>90%). The Bragg mirror configuration is also a system that makes evident the wave-like nature of the solution of the Cattaneo-Vernotte equation by showing frequency pass-bands that are absent if the materials obey the usual Fourier’s law.