Isogeometric Modeling and Experimental Investigation of Moving-Domain Bridge Aerodynamics

Computational fluid dynamics (CFD) and fluid-structure interaction (FSI) are growing disciplines in the aeroelastic analysis and design of long-span bridges, which, with their bluff body characteristics, offer major challenges to efficient simulation. In this paper, we employ isogeometric analysis (IGA) based on nonuniform rational B-splines (NURBS) to numerically simulate turbulent flows over moving bridge sections in three dimensions (3D). Stationary and dynamic analyses of two bridge sections, an idealized rectangular shape with aspect ratio 1:10 and a 1:50-scale model of the Hardanger bridge, were performed. Wind tunnel experiments and comparative finite-element (FE) analyses of the same sections were also conducted. Studies on the convergence, static dependencies on the angle of attack, and self-excited forces in terms of the aerodynamic derivatives show that IGA successfully captures the bluff-body flow characteristics and exhibits superior per-degree-of-freedom accuracy compared to the more traditional lower-order FE discretizations.