NAFEMS International Journal of CFD Case Studies

Volume 13, September 2023

ISSN 1462-236X
ISBN 978-1-83979-059-1

Low Reynolds number pressure-flow analysis across a valve: Comparison between three-point and multipoint gap functions with CFD results

Sacha Jelić, Vishnuvardhan Ranganathan, ThermoAnalytics GmbH, Germany

https://doi.org/10.59972/fek47r5s

Keywords: coupled CFD-Thermal, solar radiation, urban climate

Abstract

During summer, ambient temperatures rise significantly, with solar radiation from the sun playing a major role in intensifying urban heat. This solar energy heats concrete buildings, asphalt roads, and even pedestrians, exacerbating the urban temperature. This study demonstrates how the urban climate can be predicted around buildings or urban environments over long durations with moving sun. A CFD solver that simulates the wind, and convection can be coupled to a thermal radiation/conduction simulation tool. The thermal tool is able to simulate the incoming solar from early mornings to evening, so with a moving sun, without using large simulation time or computational resources. Convection from CFD is imported at given times or linearly interpolated with respect to windspeed and direction, which then allows temperature predictions over days, months or even a year. It will be shown how certain design choices can influence local temperatures. An illustration of this is the application of solar reflective glass windows on buildings, so that the building does not absorb the incoming radiation. Another example is the use of green roofs, which facilitate evaporation through plant transpiration, but also provide an insulation layer for the building. Such design changes lower the temperature in and around buildings, improve the comfort and reduce the energy demand that is required for active cooling systems like air conditioning.

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Cite this paper

S. Jelić, V. Ranganathan. A Coupled Simulation Approach to Urban Climate Temperature Prediction with Moving Sun for Long Transient Durations in London City, NAFEMS International Journal of CFD Case Studies, Volume 13, 2023, Pages 80-101, https://doi.org/10.59972/fek47r5s