Urban wind flows and city acoustics influence the ecology of the city and the health of people: These topics were on the agenda of the fifth event in the series on the "LIN City" (livable, intelligent and sustainable) by researchers from the iCity network in cooperation with the Stuttgart Region Chamber of Commerce and Industry.
Prof. Dr. Ursula Voß from the Faculty of Surveying, Computer Science and Mathematics and professor of applied mathematics spoke in the first block of the expert panel on the fundamentals of flow simulation and advances in workflows for web-based simulations and visualizations of urban wind flows.
Prof. Dr.-Ing. Berndt Zeitler, deputy director of the Institute for Applied Research (IAF) and professor of technical acoustics and architectural acoustics, presented his team's research on characterization, measurement and prediction of sound propagation in urban areas in the second block.
After the expert panels, the audience of 40 people had the opportunity to ask questions and make suggestions.
Dr. Dirk Pietruschka, Managing Director and himself an active researcher in the iCity network, provided the introduction to the evening. Those present were given a brief overview of the origins and development of the research partnership as well as its central research areas and strategic goals. Dirk Pietruschka focused in particular on the aspects of a city that make it a sustainable and livable place and how iCity is trying to help shape future urban development to this end through smart applications and products.
Prof. Dr. Ursula Voß opened the expert panel with the topic of urban wind flows. She began by illustrating the significance of urban wind flows as an important factor influencing health and ecological issues in the city. Influenced by this are complexes of topics such as the microclimate and, in turn, the perceived comfort in the city or the transport of pollutants through the air. Ursula Voß and her team are working, among other things, in the iCity partnership to make the possibilities of urban wind flow simulations available to a wide range of users. An interactive, browser-based application was developed for this purpose. This enables the visualization of complex flow simulations at the building level in a 3D city model environment. Thanks to clever optimizations of the building geometries and optimized computational processes, the amount of data in the calculations can be reduced, making the application available to many potential users. Due to the possibilities of different visual representations – for example via point clouds or streamlines – the application is furthermore suitable for different use cases.
The audience was able to see for themselves the possibilities and user-friendliness of the interface by means of a live demonstration of the browser application.
When asked after her presentation, Ursula Voß once again emphasized the transferability of her work. The (partially) automated processes could basically be applied wherever users have access to the necessary CityGML data (3D city model). Thus, the question about a possible application in preparatory urban planning could also be answered in the affirmative. When asked about the concrete benefits, the HFT researcher gave an outlook on the future work with their models. After the team had built up and optimized the workflow in previous work steps, they will in future be working on the simulation of concrete pollutant dispersal as well as the simulation of flow conditions for small wind turbines in urban areas. This is another approach that underscores the interdisciplinary character within the iCity research partnership.
The second expert panel of the evening was dedicated to the topic of urban acoustics. In his presentation, Prof. Dr.-Ing. Berndt Zeitler approached the field of research on the basis of the areas of outdoor space, sound insulation and indoor space.
First, Berndt Zeitler characterized the possibilities of recording noise in outdoor areas. In doing so, scientists resort to very different instruments. The lecture showed impressions from the noise mapping of outdoor space, the simulation of sound propagation as well as the different possibilities of measuring noise, for example via sensors of the Open Knowledge Lab. He illustrated another experimental approach using current student work on the perception of noise in the city. These focus on sensitizing local people to the noise in their immediate surroundings, for example through so-called soundwalks. Accompanying surveys try to capture people's perceptions. From this it could be deduced that it is not so much the level but rather the type of noise that is decisive for a disturbing perception of noise. Furthermore, the importance of urban planning on the acoustics of places could be clarified by deriving concrete planning interventions from the preliminary work in order to exert a positive influence on the local soundscape.
The area of sound insulation focused on different fields of application on the building envelope. Passive measures to reduce transmission and sound propagation by adapting materials and the configuration of the building wall, but also by structurally adapting window frames and ventilation units were presented. In this context, the researchers, together with external partners from industry, have already been able to make great progress. For example, the sound level could be reduced by more than ten decibels with (partially) open windows, which corresponds to a reduction of noise perception by half. Further work in the research area will focus on sound level measurement and sound prediction in urban areas using autonomous sensor networks.
Following the lecture, the audience was also able to draw on the contributed knowledge of the representatives of the practice partners who were also present. The organizing team of iCity and the IHK is pleased about the lively participation from research, economy and interested civil society in our seminars.