Air Flow Visualisation Towards the Design of Breathing Skins

Abstract

How can the geometric modification of surfaces affect airflow and enhance the thermal performance of ventilated facades? This study is an initial investigation into how surface articulation can affect air movement in a plenum between the shaped surface and the building, as a step toward the design of climate-specific ventilated facades, termed “Breathing Skins”. The research method describes how physical and digital procedures can play complementary roles in the understanding of complex environmental phenomena for architectural applications. Initial wind-tunnel tests measured the pressure change from the inbound side to the outbound side of a cavity with a variable shaped surface on one face. They allowed comparison of the frictional properties of a variety of folded surface forms, that could be used for façade siding or screens. Subsequently, the patterns were simulated with Computational Fluid Dynamics (CFD). Results show that a solid sheet with concertina folds parallel to the wind revealed a greater loss in pressure and a Miura-Ori pattern a smaller loss in pressure than a flat sheet. These findings are shaping further research into the phenomenon by indicating useful avenues for the development of climate-modulating outer building skins.