Three‐dimensional Numerical Simulation of Local Scour of Bridge Piers under Constant Current using Asynchronous Time Marching Scheme

Abstract Bridge failures have been frequently observed, especially caused by local scour. In recent years, we have witnessed high‐fidelity local scour simulation around bridge piers. The RANS equations are applied to effectively obtain the simulation result of local scour at the bottom of a riverbed under the influence of constant water flow. The morphology model is applied to calculate the riverbed changes, and a dynamic mesh algorithm is utilized to accordingly update the bed positions during the simulation. To reduce the high computational demands of 3D local scour simulations, the asynchronous time marching scheme is introduced to use different time steps in the updates of river and flow properties. The effectivity of the developed efficient numerical scheme for 3D local scour simulation is validated through the comparison with experimental data, which demonstrates its potential in predicting time‐dependent local scour depth and guiding bridge design to resist extreme flood events.