Title: Theoretical framework for designing phase change material systems Show Chinese title

Title: 相变材料系统的理论框架

Abstract: Phase change materials (PCMs) hold considerable promise for thermal energy storage applications. However, designing a PCM system to meet specific performance presents a formidable challenge, given the intricate influence of multiple factors on the performance. To address this challenge, we hereby develop a theoretical framework that elucidates the melting process of PCMs. By integrating stability analysis with theoretical modeling, we derive a transition criterion to demarcate different melting regimes, and subsequently formulate the melting curve that uniquely characterizes the performance of an exemplary PCM system. This theoretical melting curve captures the key trends observed in experimental and numerical data across a broad parameter space, establishing a convenient and quantitative relationship between design parameters and system performance. Furthermore, we demonstrate the versatility of the theoretical framework across diverse configurations. Overall, our findings deepen the understanding of thermo-hydrodynamics in melting PCMs, thereby facilitating the evaluation, design, and enhancement of PCM systems. Show Chinese abstract

Abstract: 相变材料（PCMs）在热能存储应用中展现出巨大潜力。然而，由于多种因素对性能的复杂影响，设计满足特定性能要求的PCM系统极具挑战性。为解决这一难题，我们提出了一种理论框架以阐明PCM的熔化过程。通过结合稳定性分析与理论建模，我们推导出一个转变准则来划分不同的熔化区域，并进一步制定出能够唯一表征典型PCM系统性能的熔化曲线。该理论熔化曲线捕捉了实验和数值数据在广泛参数空间内的关键趋势，建立了设计参数与系统性能之间的便捷且定量的关系。此外，我们展示了该理论框架在不同配置中的通用性。总体而言，我们的研究深化了对熔融PCMs热-流体力学的理解，从而促进了PCM系统的评估、设计和优化。