Flow around a pipeline and its stability in subsea trench

摘要: Offshore subsea pipelines must be stable against external loadings, which are mostly due to waves and currents. To determine the stability of a pipeline on seabed, Morrison equation has been applied with prediction inertia drag forces. When is placed in trench, force acting it reduced considerably. Therefore, consider one employ reduction factors. investigate various trenches, we numerically simulated flows over trenches compared them experimental data from PIV (Particle Image Velocimetry) measurements. The present results were produced at Reynolds numbers ranging 6×103 3×105 based diameter cylinder. Quasi-periodic flow patterns computed by large-eddy simulation terms mean characteristics for typical trench configurations (W/H=1 H/D=3, 4). conditions was addressed amplitudes oscillating lift drag, factor each case suggested design.