A numerical study on near-bed flow mechanisms around a marine pipeline close to a flat seabed including estimation of bedload sediment transport

摘要

Near-bed flow mechanisms of high Reynolds number flows around a marine pipeline close to a flat seabed have been studied using a two-dimensional standard high Reynolds number k-e model. The effects of gap to diameter ratio and seabed roughness for a given boundary layer thickness of the inlet flow upstream of the cylinder have been investigated. The vortex shedding mechanisms have been investigated. Mean pressure, mean friction velocity and the resulting mean bedload sediment transport along the bed have been predicted. Overall it appears that for engineering design purposes the present numerical model is suitable for predicting high Reynolds number flows, which are present near the seabed in the real ocean.