Comparing computational modelling of bridge wind shields to wind tunnel tests

Bridge aerodynamic studies are essential in ensuring the safety and acceptable performance of long-span bridges vulnerable to the effects of crosswinds. Aerodynamic studies were traditionally carried out in wind tunnel facilities, but there are now greater opportunities for using computational fluid dynamics modelling. Few studies of three-dimensional aerodynamic simulations of lightweight vehicles on bridges exist but there has been limited validation and verification work done to date. In the study reported in this paper, three-dimensional computational fluid dynamics models were developed for the Queensferry Crossing cable-stayed bridge in Scotland, containing wind shields and sample vehicles. The models considered the wind effects from a range of yaw wind angles and subsequently determined the aerodynamic coefficients of vehicles. The models were verified by means of a mesh sensitivity study, a domain sensitivity study and comparisons with wind-tunnel test results. The models were then validated by using the same modelling process with a different type of wind shield, and again comparing results with wind-tunnel test data for the same configuration. Results demonstrated that the modelling can determine the aerodynamic coefficients to a similar level of accuracy to that of wind tunnel tests.