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Title: Three-phase flow simulation of local scour around a submerged horizontal cylinder
Wave-induced scour plays a key role in the stability analysis of coastal structures, submarine pipelines or cables. There is a rich literature in current-induced scour, but more research is needed to understand the characteristics of wave-induced scour and the mechanisms that are important to the scour process. Sediment transport and flow-induced scour are three-phase (air-water-sediment) flow problems in nature and multi-phase flow simulation is a useful tools that can provide information difficult to obtain from physical tests. Most existing numerical models developed for simulating local scours are based on one-way coupling, which neglects effects of sediment phase on hydrodynamics of the flow. The present study uses a three-phase (air, water and sediment) flow model, which allows for a two-way coupling, to simulate wave-induced local scour problems. The three-phase flow model captures the air-water interface using a modified VOF method, and uses an improved rheology for the sediment phase for better results. The model is validated and verified using one set of existing experiment results for local scour around a submerged horizontal pipe. The detailed flow fields of both the sediment phase and the water phase around the scour are analyzed to understand the scour process. All three-phase flow simulations flow more » simulations on XSEDE’s Stampede2 supercomputers. The applicability of the model to other local scour problems is also discussed. « less
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Proceedings of the Thirtieth (2020) International Ocean and Polar Engineering Conference
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National Science Foundation
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