Simulation-based optimization of in-stream structures design: J-hook vanes

摘要

J-hook vanes are geometrically complex rock structures that are used extensively in stream and river restoration. We employ the St Anthony Falls Laboratory Virtual StreamLab (VSL3D) code to elucidate the flow and transport phenomena induced by such structures in large rivers and develop design guidelines based on this physical understanding. The unsteady Reynolds averaged Navier-Stokes module of the VSL3D model with the k - closure is used to carry out coupled hydro-morphodynamic simulations in waterways with complex hydraulic structures. We construct two virtual river geometries, representative of gravel and sand-bed rivers in nature, and employ them for developing design guidelines for J-hook vanes. We systematically simulate numerous arrangements of J-hook vanes to understand physical mechanisms via which such structures modify turbulent flow and sediment transport processes depending on river environment and structure layout. The resulting physical insights are then distilled into a set of physics-based design guidelines for optimal structure design and placement in large rivers.