A comparative study of the CFD modeling of a ventilated active façade including phase change materials

• A CFD model of a ventilated active façade with PCM was developed.
• Results were validated against real-scale experimental data.
• Convection effects within PCM can be neglected in for the façade under study.
• DO radiation model and RNG k–ε showed accurate results for air turbulent flow regime.
• k–ω models showed better accuracy than the RNG k–ε model for transitional air flows.

This article describes the development of a CFD 2D model of a new type of ventilated active façade which includes a PCM (Phase Change Material) in its outer layer. The model was carried out using the software Fluent. The numerical results were compared against experimental data obtained by means of a real-scale PASLINK test facility. Two different approaches were tested to model the PCM. To model the radiation, S2S and DO sub-models were tested. RNG k–ε, Standard k–ω and SST k–ω turbulence models were compared to model the air flow inside the ventilated layer. The results showed that for the geometry under consideration it was suitable to consider the PCM to be a solid material with variable Cp. The DO model accurately reproduced the radiation phenomena. For an air flow rate that resulted in a turbulent regime inside the air chamber, the RNG k–ε model showed good agreement between the experimental data and the simulated results. The developed model can be considered suitable for the simulation and optimization of the façade under turbulent flow conditions. Further research should be conducted to improve the accuracy of the model for low-Reynolds-number turbulence conditions.