Helium-based modelling approach for studying thermal-induced airflows in street canyon

Non-isothermal phenomena in urban environment encounter considerable challenges, particularly in sub-scale implementations. When scaling down a realistic urban neighbourhood to a physical model in an appropriate size that is applicable for laboratory tests, achieving representative thermal boundary conditions often necessitates unrealistically high temperatures. To address this, a helium-based modelling approach is proposed as a cost-effective and safer alternative to traditional heating methods in wind tunnel experiments. By simulating buoyancy effects using helium, this method replicates thermal airflows, enabling the study of buoyancy-driven flow characteristics and heat distribution in urban spaces. A single street canyon model was employed to validate the similarity between hot air and helium within this framework. Preliminary results demonstrate the approach’s effectiveness and underscore its potential to advance urban environment research.