Theoretical and testing investigation of wind–rain coupling loads on some typical bluff bodies

Abstract

The article presents a mathematical theoretical framework and fitting parameters with aspects of joint probability distribution of wind and rain, separate wind and rain action, and coupled wind and rain effects on steady and unsteady forces acting on some typical bluff bodies. Gumbel and copula functions were first selected to describe the joint probability distribution of wind speed and rain intensity. Then, two models, a raindrop impact model and an equivalent air density model, were adopted to quantify the loading action considering only separate wind and rain action, and simplified coupled effects with superimposition of wind and rain show that it would be accurate enough to neglect separated rain influence in steady wind and rain loading conditions. Furthermore, wind tunnel testing has been carried out under coupled wind and rain conditions with the help of a high-precision raining simulation system in TJ-1 wind tunnel on various reduced-scale models with some typical cross sections, such as circular and rectangular, thin plate, and streamlined box, and their aerodynamic loading and wind–rain-induced performance have been systematically compared. It has thus been found that the coupling effects of wind and rain should not be neglected in steady and unsteady force models.