CFD Modelling of Local Scour around a Bridge Pier

Scouring at bridge piers is problematic and unavoidable at the same time. The majority of the studies to predict scour depth carried out in the last 6 to 7 decades have been empirical, completely disregarding the physics of the problem. This study utilizes the two versions of the CFD numerical model SSIIM viz. SSIIM 1 and SSIIM 2, in order to simulate the scour around bridge piers.

The SSIIM model solves the three-dimensional momentum and continuity equations coupled with the sediment transport equations to calculate and predict the equilibrium scoured bed. In this study, the model has also been validated using experimental data available in the literature. Moreover, SSIIM 2 offers a nested grid approach in which a coarse resolution grid is used to discretize the entire domain, and a fine resolution grid is utilized to discretize the area around the pier. This approach saves both time and computational resources. The performance of the two versions of SSIIM is evaluated, and results are presented.