Effect of Non-Isothermal Conditions on Wind Patterns Near Isolated High-Rise Buildings

Abstract Variations in temperature stratification conditions can change the pattern of airflow and the distribution of pollutants in urban environments. The present study explores the intricate dynamics of wind patterns within urban settings, focusing on their crucial role in evaluating wind power potential, managing air pollution, reducing urban heat island effects, ensuring urban air mobility safety, and improving pedestrian thermal comfort. It addresses the gap in understanding airflow, thermal conditions, and turbulence around buildings, emphasizing the impact of urban designs on wind behavior and temperature layers. Extending our previous research on airflow around high-rise structures, this work explores non-isothermal conditions using data and geometry from Tokyo Polytechnic University’s (TPU) wind tunnel facility. Utilizing advanced computational fluid dynamics (CFD) models, such as Unsteady Reynolds-averaged Navier-Stokes (URANS) in OpenFoam, this study predicts wind velocity, turbulence, and temperature distribution around a single isolated building. It further analyzes the effects of thermal stratification through spectral and proper orthogonal decomposition (POD), uncovering the significant influence of thermal state changes on turbulence kinetic energy. The findings indicate the complex interactions between thermal layers, urban airflow, and architectural configurations, providing valuable insights for urban planning and design. This knowledge is essential for better understanding air pollution distribution, enhancing distributed energy systems’ efficiency, and building energy performance in densely populated areas, offering a pathway to optimize microclimatic control and contribute to sustainable urban development.