Numerical multiphysics modelling for the assessment of thermo-physical and energy performance of an advanced semi-opaque active façade

The aim of this paper is to study an advanced semi-opaque active façade using a multi-physics modelling approach. The studied façade is to be understood as an integrated energy system as designed with innovative materials and system solutions. It is an envelope building component composed of opaque modules combined with transparent ones, in which multilayer panels are integrated, consisting of nano-structured materials and new-generation photovoltaic systems. The multi-physics approach used for simulations allowed consideration of fluid-dynamics and thermal behaviour of the components, including the phase change material (PCM) occurring in one of the system elements under external microclimatic stress, modifying its heat capacity over time. Numerical modelling based on RANS-turbulence models was implemented to simulate the multi-layer components. In particular, numerical solutions of buoyancy / forced driven flows and temperature fields were developed by means of an energy equation, taking into account the enthalpy variation in the solid/liquid computational domain connected with the phase change process. Simulation results show the airflow and thermal map computed in a chosen constraint configuration of the integrated system façade.