Unravelling the Impact of Urban Morphology on Non-Isothermal Flow Dynamics

Abstract: Urban areas are renowned for their intricate atmospheric dynamics, influenced by diverse building configurations. Understanding the implications of urban morphology on flow patterns, ventilation, and heat dissipation is crucial for urban climate management. However, comprehending the interplay between thermal-driven buoyancy flow and urban morphology remains a challenge. Despite ongoing research efforts, a comprehensive understanding of heat transport and fluid flow in complex urban environments remains elusive. To address this gap, we developed 3D parametric urban models resembling Singapore's urban morphology and accounting for buoyancy effects. Using simultaneous Particle Image Velocimetry (PIV) and Laser-Induced Fluorescence (LIF) measurements in a large closed-circuit water tunnel, we captured high-resolution heat and fluid flow behaviours under various configurations. Our study meticulously documents the development of non-isothermal urban flow, highlighting heat plume generation from the ground, buoyant updraft development, and temperature variations along the flow. Keywords: Urban flow, Water tunnel, Particle image velocimetry, Laser-Induced Fluorescence, Buoyancy-driven flow