Study on Hydrodynamic Coefficients of a Submarine Piggyback Pipeline under the Action of Waves and Current

Abstract

In this study, physical model tests are used to investigate the effects of a varying number of wave and current parameters, the gap ratios between the pipeline and seabed, the spacing ratios between the two pipelines and the diameter ratios on the hydrodynamic coefficients of the large, small pipeline and pipeline system (bundle) in a piggyback configuration under the combined action of waves and current. The results show that, compared with the pure wave field, the existence of the steady current will lead to a decrease in hydrodynamic coefficients. In addition, the results indicate clear differences between the hydrodynamic coefficients of the large pipeline, small pipeline and piggyback pipeline system. The experimental results on hydrodynamic coefficients can be used as an important basis for the safety design of a submarine piggyback pipeline.

Experimental Studies on Vortex-Induced Vibration of a Piggyback Pipeline

“…The inverse change was observed when α was increased from 90 • to 180 • . Cheng et al [5] examined the effects of gap distance between the pipeline and seabed, G/D, and d/D on the hydrodynamics a piggyback pipeline with α = 90 • in waves and currents in a wave flume. It was found that when G/D > 0.6, the effects of G/D on the hydrodynamics were weakened.…”