Numerical investigation of the thermal performance of CPCM in T-Slot profile channel for potential compactness in modular energy storage

<p dir="ltr">The encapsulation of advanced solid rigid composite phase change materials (CPCMs), primarily in solid-pellet form, presents significant challenges when applied to complex geometries, especially those with internal fins featuring intricate curved or branched structures. For example, biomimetic-inspired designs can hinder the proper placement of standard-shaped pellets. Additionally, external fins intended to enhance discharging in?crease the overall channel domain, consequently reducing system compactness in modular form. To overcome these limitations, square variants of the T-slot profile are proposed to provide defined spaces for CPCM pellets with a centrally located heat source for uniform symmetrical charging. The curved slots extend the heat transfer pathways, creating a fin-like effect internally that enhances charging performance, while also increasing the external heat transfer area to facilitate effective discharging without the need for additional expansion of the original domain. A comprehensive numerical analysis of the proposed models is conducted to compare the performance against a reference geometry of equal domain and having the same amount of PCM. The numerical scheme is validated against a lab-scale experimental prototype, not relying on previously published models for validation. The T-slot variants showed up to 27.9 % faster charging, with 9.69–14.7 % time savings for G2 and G3. Charging heat transfer coefficients improved to 60.8–73.9 W/m² ⋅K vs. 56.7 for the reference. During dis?charging, heat extraction increased with coefficients up to 74.90 W/m²⋅K, demonstrating significantly enhanced thermal performance across all T-slot geometries. Overall, other performance parameters in the study further highlight the power and cost-effectiveness potential of the proposed designs.</p>