Transient hydrodynamic phonon transport in two-dimensional disk geometry

Chuang Zhang, Lei Wu

Published 2022-03-24Version 1

This paper is a continuation of our work on the transient hydrodynamic phonon transport from three-dimensional to two-dimensional materials. In the previous work [Zhang \textit{et al.}, Int. J. Heat Mass Transfer 181, 121847 (2021)], a transient heat conduction phenomenon proving the existence and uniqueness of hydrodynamic phonon transport in three-dimensional materials was found, namely, using a heating laser pulse to heat the materials under the environment temperature, after the heating laser is removed, the transient temperature could be lower than the environment temperature. Whether this phenomenon could appear in two-dimensional materials needs further study. In this paper, the transient heat conduction in two-dimensional disk geometry is studied based on the phonon Boltzmann transport equation (BTE). Our results show that this phenomenon could appear in two-dimensional disk geometry and only appear in the hydrodynamic regime. In addition, the possibility of this phenomenon observed by experiments is theoretically discussed by using the experimental parameters as the input of the phonon BTE. Results show that this phenomenon could appear in a single-layer suspended graphene disk with diameter $7~\mu$m in the temperature range of $50-150$ K. The present work could provide theoretical guidance for the future experimental proof of hydrodynamic phonon transport in two-dimensional materials.