A. Kubilay

Computational fluid dynamics simulations of wind-driven rain on a mid-rise residential building with various types of facade details

Numerical studies of wind-driven rain (WDR), reporting detailed analysis of rain exposure on building facades, focus mainly on simplified building facades. However, small-scale facade details have a large impact on the rain exposure of a building, redistributing WDR locally. The present study reports results of computational fluid dynamics simulations with Eulerian multiphase (EM) model for WDR on a stand-alone mid-rise residential building. The influence of facade details, namely roof overhangs, balconies and window sills, is analysed. It is shown that even a very small surface detail, such as a window sill with a size of 0.10 m, can decrease catch ratio by up to 37% and droplet impact speed by up to 40%. Numerical simulations also show the practicality of the EM model for detailed analysis of WDR intensity on a complex building and its ability to be used as a design tool.

Rain sheltering analysis in semi-outdoor environments: case study on passenger comfort in a railway station shelter

Wind-flow field around a semi-outdoor structure can differ significantly from the one around a building. As a result, the design of such a structure can have a strong impact on the rain exposure. This paper studies the wind-driven rain (WDR) sheltering for a prototype of a small railway station shelter designed for rural areas. Computational fluid dynamics simulations of WDR are performed based on an Eulerian multiphase model. A new metric called “wetting ratio” is proposed, which allows for quantitative analysis of wetting due to rain within a volume in the air. The rain exposure of standing passengers is discussed for a range of meteorological conditions based on yearly climate data. The analyses indicate the critical meteorological conditions and orientations that lead to the highest rain exposure. It is found that minor geometrical modifications, such as side window length, can have a significant impact on the rain exposure.