Unconventional permeable microstructures: An engineered porous material

Abstract

Designing energy-efficient facades can have a significant impact on reducing the building's energy consumption while providing comfort for the occupants. While highly-insulated buildings have good thermal insulation and high airtightness, they deal with the risk of overheating issues. Dynamic insulation, a technology consisting of porous materials, is a responsive building element that has been introduced to the built environment to tackle these problems. Due to the current lack of information and available resources on dynamic insulation, and its possible contribution to the built environment, the presented research focuses on the effect of complex geometries as the air channels in dynamic insulation, and as part of the overall building wall. This thesis aims to discover whether and how a designed microstructure (now possible by Additive Manufacturing) in dynamic insulation can offer a solution for controlling the airflow passing through the wall and therefore, improving the performance of the dynamic insulation. The methodology of the thesis started with the literature review and studying different articles and books. Then in a design-through-research approach, various parameters were identified that could affect the airflow rate and pattern. These parameters were categorized in two groups with relation to geometry and texture. The dominant factors were then selected to be further analyzed. Next, different geometries were generated using the 3D sampling method, based on different textures with different properties. The engineered geometries are texture-based metamaterials with cavities. To investigate the behavior of airflow in these geometries, CFD simulations were performed in Ansys Fluent. The results were evaluated based on their correspondence to the research objectives and conclusions were drawn to answer the research questions. Keywords: Texture-based metamaterials with cavities, complex geometries, dynamic insulation, porous materials, airflow behavior, responsive building elements.