Double-skin façade simulation with computational fluid dynamics: A review of simulation trends, validation methods and research gaps

Dynamic simulation of a double-skin façade (DSF) with computational fluid dynamics (CFD) can be challenging due to the lack of validated models and benchmarking datasets. Furthermore, there is a lack of consensus in the scientific community on what constitutes a successfully validated DSF model. The present review study identifies simulation trends and research gaps for DSFs simulated with CFD. Additionally, this article presents a series of CFD simulations in which key aspects of the DSF modelling are varied: 2D or 3D modelling approaches, turbulence viscosity models (TVMs), radiation models, and wall function. These simulation results are compared to the empirical data (both temperature and velocity fields) of a benchmark test with laboratory-controlled boundary conditions. This analysis shows that using the k-ε RNG model with enhanced wall treatment and surface-to-surface (S2S) radiation model yields the best results for the 2D case of natural convection flow. Moreover, it is shown that accounting for the velocity field in the validation process is essential to ensure the suitability of a model. Finally, the authors advocate for the use of selected dimensionless numbers to improve the comparability of the different DSF scientific studies. This would also help to identify relevant experimental datasets for validation and suitable CFD simulation settings for specific DSF cases.