Large Eddy Simulation of the wave loads on submerged rectangular decks: Fid-Bau Portal

Large Eddy Simulation of the wave loads on submerged rectangular decks

Chu, Chia-Ren / Huynh, Le-Em / Wu, Tso-Ren

Highlights • Verified LES model is used to study the wave loads of submerged bridge decks. • The effects of wave height, submergence ratio, and blockage ratio are studied. • The wave loads are linearly proportional to the incoming wave height H. • Maximum wave load occurs when the deck is right beneath the mean water level. • Blockage effect on the drag, lift, and pitching moment coefficients are minor.

Abstract This study integrates a Large Eddy Simulation model and the Volume of Fluid method to investigate the wave loads on submerged bridge decks. The simulated wave height and surface pressures on the deck are validated by the experimental results of a laboratory flume. The numerical model is utilized to examine the wave/turbulence interaction around a rectangular deck near the water surfaces. In addition, the effects of wave height, scale ratio, submergence ratio, and blockage ratio on the wave loads of the submerged deck are investigated. The simulation results indicate that the drag, lift, and pitching moment on the deck are linearly proportional to the wave height H, and a new normalization scheme is proposed to predict the wave loads of partially and fully submerged decks. On the other hand, the dimensionless force coefficients are functions of submergence depth S, regardless of the scale ratio of the deck model. The maximum force coefficients occur when the submergence ratio S/D = 0∼1.0 and decrease with the increasing submergence ratio, resulting from the wave-induced pressure is largest near the water surfaces. Furthermore, the turbulence induced by the wave breaking and by the bridge deck affects the surface pressure and hydrodynamic force of the partially submerged bridge deck.