Recent observation of second sound in graphite at a temperature above 100 K has aroused a great interest in the study of thermal waves in non-metallic solid materials. In this article, based on the Guyer–Krumhansl model, we investigate the second sound and thermal resonance phenomena in phonon hydrodynamics. The occurrence condition for the second sound is derived. It shows that the smaller the relaxation time of N-scattering of the non-metallic solid with a large relaxation time of R-scattering, the more likely the second sound will occur. For the phonon transport in the non-metallic solid excited by an oscillatory heat source with a single frequency, the occurrence condition for thermal resonance and a formula for calculating the external heat source frequency at resonance are also derived. It is found that the low-dimensional materials with small size are prone to the occurrence of second sound and thermal resonance. These phenomena open up new avenues for thermal management and energy conversion.

最近对温度超过100 K的石墨中第二声的观察引起了对非金属固体材料中热波研究的极大兴趣。在本文中，基于Guyer-Krumhansl模型，我们研究了声子流体动力学中的第二声和热共振现象。导出第二声音的发生条件。结果表明，非金属固体的N散射的弛豫时间越短，R散射的弛豫时间越长，第二种声音发生的可能性就越大。对于由单一频率的振荡热源激发的非金属固体中的声子输运，还推导了热共振的发生条件和共振时外部热源频率的计算公式。发现具有小尺寸的低维材料易于发生第二声音和热共振。这些现象为热管理和能量转换开辟了新途径。