Thermal energy storage in the phase change materials (PCMs) around a confined heated cylindrical heat source has been investigated numerically. This work aims to explore three major objectives namely; evolution of melting front around the cylindrical heat source, quantification of overall rate of heat transfer and identifying the factors to maximize the energy storage. The enthalpy-porosity formulation is utilized to model melting of PCMs. The flow and energy equations with relevant boundary conditions have been solved using finite element method for range of parameters as Rayleigh number $({10}^2\le Ra\le {10}^6)$, Prandtl number $({10}^2\le Pr\le {10}^3)$, Stefan number $(0.01\le S{t}_e\le 0.5)$ and aspect ratio $(0.1\le AR\le 0.5)$. The evolution of melting front and melt fraction, streamlines, isotherms, Nusselt number and thermal energy storage are reported as a function of Rayleigh number ($Ra$), Prandtl number ($Pr$), Stefan number ($S{t}_e$), and aspect ratio ($AR$). Stefan number and the aspect ratio have shown to be a positive influence on the amount of thermal energy absorbed during the melting of PCMs. At low Rayleigh and Stefan number, melting kinetics is shown to be sluggish. All else being equal, the energy storage exhibits three distinct regimes depending upon the Fourier number namely, the lag phase, the exponential phase and stationary phase. For process design calculations, the gross engineering parameters like Nusselt number and steady-state melt fraction are often required, and therefore a predictive correlation for the value of the average Nusselt number is proposed to facilitate the estimation of average Nusselt number at intermediate values of dimensionless numbers for a given practical application.

已经对受限加热圆柱形热源周围的相变材料 (PCM) 中的热能存储进行了数值研究。这项工作旨在探索三个主要目标：围绕圆柱形热源的熔化前沿的演变，整体传热速率的量化和确定最大化能量存储的因素。焓-孔隙率公式用于模拟 PCM 的熔化。使用有限元方法求解了具有相关边界条件的流动和能量方程，参数范围为瑞利数 $({10}^2\le \mathrm{电阻}\mathrm{一种}\le {10}^6)$, 普朗特数 $({10}^2\le 磷r\le {10}^3)$, 斯蒂芬数 $(0.01\le 秒{吨}_{\mathrm{电子}}\le 0.5)$ 和纵横比 $(0.1\le \mathrm{一种}\mathrm{电阻}\le 0.5)$. 熔融前沿和熔融分数、流线、等温线、努塞尔数和热能储存的演变报告为瑞利数的函数。$\mathrm{电阻}\mathrm{一种}$), 普朗特数 ($磷r$), 斯特凡数 ($秒{吨}_{\mathrm{电子}}$) 和纵横比 ($\mathrm{一种}\mathrm{电阻}$）。Stefan 数和纵横比已表明对 PCM 熔化过程中吸收的热能数量有积极影响。在低瑞利数和斯特凡数下，熔化动力学显示缓慢。在其他条件相同的情况下，能量存储根据傅立叶数表现出三种不同的状态，即滞后阶段、指数阶段和稳定阶段。对于工艺设计计算，通常需要努塞尔数和稳态熔体分数等总体工程参数，因此提出了平均努塞尔数值的预测相关性，以促进无量纲中间值处平均努塞尔数的估计。给定实际应用的数字。