Closing the gap between simulation and reality in phase change material storage: A validated model with shrinkage, air gaps, and realistic thermal boundaries
International Communications in Heat and Mass Transfer, cilt.179, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 179
- Basım Tarihi: 2026
- Doi Numarası: 10.1016/j.icheatmasstransfer.2026.112428
- Dergi Adı: International Communications in Heat and Mass Transfer
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO)
- Anahtar Kelimeler: Enthalpy–porosity method, Experimental validation, Natural convection, Phase change material (PCM), Realistic boundary conditions, Volume of fluid (VOF)
- Kocaeli Üniversitesi Adresli: Evet
Özet
The pervasive use of idealized boundary conditions in numerical models of phase change materials (PCMs) leads to a significant and often unquantified overprediction of performance, undermining the reliable design of latent heat thermal energy storage (LHTES) systems. This study presents an integrated experimental-numerical framework that decisively bridges this simulation-reality gap. Through the melting of paraffin in a bottom-heated cavity, we show that conventional assumptions such as adiabatic walls and constant-temperature heating overpredict the melting rate and stored energy by up to 34.4% and 9.5%, respectively. By progressively incorporating experimentally measured transient heating, convective losses, air-gap effects, and crucially, shrinkage-induced interface deformation, we develop a high-fidelity model. This comprehensive approach reduces the mean prediction error to just 3.5%, achieving strong agreement (R2 = 0.997). Our results establish that the often-ignored volumetric shrinkage, which creates a curved air gap, is not a minor detail but a dominant physical mechanism that retards melting and reshapes the PCM phase front. The progressive reduction in prediction error demonstrates that accurate PCM modeling requires the simultaneous consideration of transient thermal boundaries, air-gap formation, and shrinkage-induced geometric deformation. This work provides a validated modeling paradigm essential for the accurate design and optimization of real-world LHTES units in solar thermal and building applications.