Three dimensional snalysis of flow around a porous spur dike

Abstract

The goal of study described in this paper is to develop the three dimensional analytical model to simulate a flow around a porous structures. The VOF method was used for the free surfacce flow field considering the future applicability to the rapid changes of the flow such as a surge flow. The flow in porous media was modeled by the Brinkman-Forchheimer extended Darcy's equation. As the experimental verification, three dimensional velocities around a spur dike were measured by using Acoustic-Doppler Velocimeter (ADV). The numerically obtained flow profile around a permeable spur dike was compared with the experimental results. It is confirmed that agreement between proposed numerical result and experiment is good under sub-critical flow condition. Some limitations according to mesh size and boundaries were exposed, nevertheless applicability of the model was proved. The present study enables the future simulation of rapidly varied flow around permeable hydraulic structures.

Three-Dimensional Flow Characteristics in Slit-Type Permeable Spur Dike Fields: Efficacy in Riverbank Protection

“…Certain researchers [40] examined permeable spurs as rubble-mound structures using laboratory experiments and a two-dimensional model focusing on the rubble geometry of a group of groins in terms of the flow structure and the flow force. A study [41] examined the three-dimensional flow features around a porous spur dike by developing a three-dimensional analytical model using the k-ε model of turbulence and found some discrepancies downstream of the spur dike. Another study [17] used a laboratory experiment to compare suspended sediment transport in permeable and impermeable spur dike fields and concluded that the suspended sediment concentration decreases in the downstream direction due to sedimentation in the transition zone for permeable spur dikes; they used a staggered group of poles as an individual spur dike.…”