Seabed shear stress amplification around subsea pipelines: Part 2, 2D parametric study with waves and combined waves/currents

© 2015 Taylor & Francis Group, London. This paper presents the results of 2D CFD modelling using ANSYS Fluent, which has been undertaken for a parametric range of over 200 cases, including over 60 different seabed geometries, pipe diameters and seabed roughnesses as well as a range of steady current, wave and combined wave/current cases. Analysis of the results focusses on evaluation of seabed shear stress amplification factors compared to far-field ambient values under wave and combined wave/current conditions for both gap (spanning) and non-gap geometries. The results have relevance to the prediction of both scour and sedimentation (backfilling) under both clear-water and live-bed conditions, particularly for insights into the importance of seabed profile changes due to long-exposure slow-processes. The results have relevance to improving models of equilibrium scour depths, especially in the presence of seabed berms and/or partial pipeline lowering.