Heat absorption performance of ultrasonic-assisted phase change thermal management units: A numerical study

The demand for more efficient thermal management increased due to their key impact on safety and reliability, especially in electronic devices. Phase-change-based devices were emerging as effective heat sinks because they could absorb significant heat during phase change. Meanwhile, ultrasonic could be adopt to overcome poor thermal properties of phase change materials (PCM). In present study, ultrasonic-assisted PCMs were proposed, whose numerical model was developed by adding a momentum source and an equivalent thermal conductivity and validated by experiments. The melting performance, thermal response, flow, heat transfer and heat absorbing characteristics of non-ultrasonic and ultrasonic-assisted PCM units were performed. The influence mechanism of ultrasonic power was also investigated. Resulted that ultrasonic led to faster melting in all directions, with a significant effectiveness of solving the difficult bottom melting. The integral-average thermal response rate of ultrasonic-assisted PCM units at 120 W reached a 354.74% enhancement compared with the non-ultrasonic. The ultrasonic-assisted PCM units could achieve a 372.00% enhancement ratio of heat absorption rate per unit mass, maintaining high-efficiency heat absorption performance during the whole phase change process, showing rapid heat absorption, compact size, and lighter weight, exhibiting the attractive potential and wide application prospects, particularly for managing heat in electronic devices requiring precise temperature control within limited spaces. Ultrasonic-assisted PCM shown significantly higher heat flux of heat source walls, enabling electronic devices to handle greater thermal fluctuations while maintaining safe operation at a constant temperature.