Conceptual Design of Freeze‑Cast Porous Structures for Advanced Sustainable Thermal‑Systems

Freeze casting, a well-established processing technique for producing porous structures with directionally aligned pores, provide a unique combination of high surface‑area‑to‑volume, and anisotropic thermal transport, promising a platform for next‑generation sustainable heat‑exchanger components. Recent work on freeze‑cast regenerators demonstrated 10–15% higher heat‑transfer performance than conventional packed‑bed, under passive oscillating‑flow water conditions (ΔT = 10 K, T = 15–30 °C) at matched pressure drop, confirming the feasibility in heat‑exchange [1]. This design approach is informed by recent advances in directional freeze‑casting, which show aligned porous structures can be engineered with predictable transport pathways suitable for energy‑conversion and thermal‑management [2]. While such materials have been studied at microstructural level, their potential in macro-scale heat exchanger design remains insufficiently explored. Unlike prior studies, which focus on microstructure, this work introduces first conceptual, component‑level framework for integrating freeze‑cast structures into general heat‑exchangers. It proposes new integration strategies as: freeze‑cast lamellar plates as replacements for conventional internal fins/passive inserts. A conceptual design framework is presented that examines incorporation of freeze‑cast structures into heat‑exchangers from a macroscopic engineering‑design perspective, focusing on qualitative relationships between pore morphology and expected transport behavior such as flow guidance, and heat‑transfer pathways. The framework emphasizes design‑relevant considerations including component integration, flow alignment, and potential roles as structured inserts or passive enhancement elements. By synthesizing insights from directional freeze‑casting research and established heat‑exchanger design principles, this work outlines novel design routes for future investigations into material‑efficient sustainable thermal systems.

References

[1] J. Liang, C.D. Christiansen, K. Engelbrecht, K.K. Nielsen, R. Bjørk, C.R.H. Bahl, Heat transfer and flow resistance analysis of a novel freeze-cast regenerator, Int. J. Heat Mass Transf. 155 (2020). https://doi.org/10.1016/j.ijheatmasstransfer.2020.119772.

[2] S. Shaik, V. Kumari Jha, G. Bae, D. Kim, Flow-driven directional freeze-casting of graphene aerogels on tubular components for enhanced thermal energy management, Energy Convers. Manag. 325 (2025). https://doi.org/10.1016/j.enconman.2024.119389.