Urban air mobility in the built environment: A review of aerodynamic interactions, thermal effects, and simulation challenges

Urban Air Mobility (UAM) is poised to transform urban transportation, yet its integration into dense metropolis introduces significant aerodynamic and thermal challenges. This review analyzes over 150 publications to assess how urban environments influence urban air mobility (UAM) safety and stability. It shows that the urban wind complexity driven by building density, height, shape, and layout, generates turbulence, wake vortices, and wind shear that threaten UAM safety during takeoff, landing, and hovering. Urban heat islands and surface heterogeneity further intensify buoyancy-driven turbulence, increasing risks for low-altitude flight paths. The paper also highlights the critical but underexplored interaction between urban turbulence and aircraft downwash, which significantly affects flight performance but lacks sufficient quantitative research. In addition, achieving computationally efficient and accurate urban airflow simulations remains a major challenge. Although hybrid modeling approaches and real-time data assimilation are proposed to enhance flight path planning and dynamic risk assessment, current research efforts are not yet adequate to fully support safe and scalable UAM deployment in complex urban environments. Overall, there is an urgent need for more targeted and interdisciplinary studies to address the unique operational risks. Advancing the understanding of urban environmental dynamics and their impact on UAM operations is essential for establishing a robust, data-driven foundation for safe and efficient urban air traffic management and the sustainable development of UAM technologies.