Coaction of Wind and Rain Effects on Large-Span Hyperbolic Roofs

Fangjin Sun,Daming Zhang,Yanlu Wang,Zhonghao Xu,Letícia Fleck Fadel Miguel

doi:10.1155/2021/9942223

Abstract

Rainfall is often accompanied by strong winds. The large-span roof structure has a low height, its surrounding turbulence is high, and the wind speed changes greatly. The effects of coaction of wind and rain on the roofs cannot be ignored. Wind-driven rain (WDR) is an oblique movement phenomenon of raindrops generated by wind flow. Four types of hyperbolic roofs, that is, square, rectangular, circular, and elliptical, are selected as the objective to study the wind-driven rain by CFD simulation. Effects of wind direction, wind speed, and rainfall intensity on the WDR are analyzed. Pressure distribution of four types of hyperbolic roofs under coaction of wind and rain is obtained. The results are compared with those from the wind action only. The roofs are partitioned to obtain the coaction of wind and rain pressure of the four large-span hyperbolic roofs with different shapes under the most unfavorable working conditions. The results show that the average pressure coefficient of the roof surface increases with the increase of wind speed and rainfall intensity. The reference value of the average pressure coefficient of wind-driven rain on the surface of the roof is given, which provides a reference basis for the design of wind-driven rain on similar hyperbolic roofs.

Highlights

Rainfall is often accompanied by strong wind
Due to its low height, the surroundings have high turbulence and large changes in wind speed. erefore, the effect of wind-driven rain on long-span hyperbolic roofs cannot be ignored. It is of great theoretical significance and engineering value to study the pressure distribution characteristics caused by wind-driven rain in long-span hyperbolic roofs
Some limitations of this study and suggestions for further research will be presented. e proposed partition value of the average pressure coefficient of the roof surface proposed in this paper is suitable for large-span hyperbolic roofs of about 20∼40 m, but it does not represent all large-span hyperbolic roof structures

Summary

Introduction

Rainfall is often accompanied by strong wind. When raindrops fall, they are affected by their own gravity, and by the wind speed. erefore, the raindrops do not hit the wall and roof of the building vertically but fall at an angle. Wu [14] used CFD to analyze the general distribution and overall trend of winddriven rain load on the windward side of low-rise buildings in 2D wind field and 3D wind field under different wind speed, wind direction angle, and rainfall intensity. The Euler-Euler method is used to numerically simulate the four hyperbolic roofs of square, rectangular, circular, and elliptical shapes, and the influence of wind speed, wind direction angle, and rain intensity on the surface pressure of the four hyperbolic roofs is studied.

Methodology

Numerical Simulation of Wind-Driven Rain

Findings

Discussion