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Abstract
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This study numerically investigates the thermal enhancement of a finned-tube phase change
material (PCM) heat exchanger integrated with open-cell metal foams for building HVAC
(Heating, ventilation and air conditioning) applications. The novelty of the work lies in a systematic
transient CFD-based parametric analysis of metal foam–PCM synergy, considering foam
material, porosity, airflow velocity, and fin number simultaneously under realistic HVAC operating
conditions. Copper tubes filled with PCM-A27 and equipped with aluminum fins are
analyzed, while aluminum and copper metal foams with different porosities are embedded inside
the PCM to overcome its inherently low thermal conductivity. The transient simulations are
performed using the enthalpy-porosity technique to evaluate melting, liquid fraction formation,
temperature variation in PCM, and the outlet air temperature. The findings obtained demonstrate
that for copper foam with porosity ε = 0.905, the melting time of PCM can be shortened by 73 %
at an air velocity of 3 m/s and 78 % at 5 m/s compared to the melting time in pure PCM.
Moreover, the outlet air reaches near inlet temperature after 248 s at 3 m/s and 213 s at 5 m/s,
corresponding to reductions of 65 % and 71.8 % in thermal equilibrium time, respectively. A fin
number of 90 combined with Cu foam (ε = 0.905) yields the most uniform liquid fraction distribution
and the highest outlet air temperature. The findings confirm the strong potential of
metal foam–enhanced PCM heat exchangers to significantly improve thermal response and energy
efficiency in modern HVAC systems.
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