To combat health induced effects related to air pollution, high air temperatures, wind and noise in the built environment in a sustainable way, environmental studies for complex situations do often need sophisticated techniques to numerically predict atmospheric boundary layer (ABL) wind flow and acoustic fields. Moreover, as sound propagation related to distant environmental noise sources (road, rail and ariplane traffic, wind turbines) is heavily influenced by the fluid dynamics of the lower part of the ABL, a combined solution of the wind flow and acoustic fields is needed. Whereas both these physical phenomena are governed by the same equations, they need to be solved separately from a numerical point of view. This has partly caused that acoustic propagation techniques and techniques to model the ABL wind flow have evolved in parallel, with separate specialists. This interdisciplinary project brings together specialists of both fields to bring forward the state-of-art numerical techniques for large (urban) areas. In this project, research will be conducted to increase the modelling accuracy for different kinds of ABL flow (neutral, stable and unstable) for the most commonly used computational fluid dynamics (CFD) methods, i.e. RANS (Reynolds-averaged Navier-Stokes) and LES (Large Eddy Simulation). Simultaneously, the recently developed open-source 3D efficient acoustic propagation method, openPSTD, will be further developed to accurately and efficiently predict atmospheric sound propagation from distant noise sources (up to several kilometers) including wind fields and atmospheric turbulence. As a result of both efforts, the sensitivity of the modelled ABL on sound propagation will be investigated for the four defined project configurations, i.e. a configuration of a flat terrain and a profiled terrain, a flat terrain with a noise barrier, and finally an urban topology formed by building blocks.
Moreover, an experimental campaign will be launched to collect validation data for the numerical models by simultaneous measurements of sound propagation and the wind field in two of the project configurations. This will be done using both a controlled setup, with an artificial sound source, and in a setup using a long term monitoring method relying on real-life noise sources.