Modeling the influence of fountain on urban microclimate

Abstract

Fountains are delightful sceneries and can provide refreshing surrounding atmosphere, because of the cooling and humidifying effect of water droplets. To create more pleasant environment, it is valuable to quantify the thermal effect of fountains. This paper introduces a numerical fountain model based on particle-source-in-cell (PSI-Cell) model coupling the jet breakup process, the heat, mass and momentum transfer between droplets and air, and the CFD model of airflow, in which the influence of fountain is taken as source terms. A field measurement was conducted, where the data of one hour was selected to validate the fountain model. The presented model is proved to have good precision in the comparisons against the measured temperature and humidity. This new model is capable of estimating the trajectories of droplets, as well as the impact of fountains on the wind velocity, temperature and humidity in the ambient area. Both the numerical and experimental results show that the fountain can improve the thermal environment in the leeward area by strong cooling and humidifying effect, while minor changes have been made in the windward and lateral areas.