Kirigami-inspired wind-steering for ventilation of urban shading structures*

While passive shading solutions—e.g., façades, "streeteries" and cloth canopies protecting street canyons—can regulate temperatures and reduce energy needs in urban settings, existing designs often block air flow, trapping heat and harmful particles. To address the need for simultaneous shading and ventilation, we propose a kirigami-inspired solution. In kirigami, adding cuts to sheets frees sections to buckle and tilt when the sheet is stretched, thus transforming a 2D structure into a porous 3D one. Here, we use Large Eddy Simulation (LES) to examine how such angled features, placed at the top of an otherwise enclosed space, affect ventilation in the presence of oncoming wind. In particular, we study how geometry affects the Air Exchange Rate (ACH) and local air circulation, examining both mean flow (dispersive) and turbulent air exchange. Additionally, our simulation results are complemented by qualitative data from wind tunnel experiments.