Session: 09-01-11 Wind Energy: Cables 1

Paper Number: 121562

121562 - The Influence of Current Profile on On-Bottom Stability of Subsea Cable 

With the development of offshore wind industry, the demands for subsea cables to transfer electricity over distance have increased. An important design criterion for subsea cable is to ensure the on-bottom stability of cable under the hydrodynamic loads induced by combined wave and current. In most cases the effect of current is dominant in the hydrodynamic force. An appropriate  current profile is needed to describe the reliable hydrodynamic loads on the cable.

In the present study, the on-bottom stability analysis of a subsea cable is performed by finite element method to investigate the influence of the boundary layer on the dynamic response of subsea cable. A case study is conducted on a subsea cable with diameter of 178 mm for three types of seabed, i.e. sand soil, clay soil and rock. The effect of two different current profiles on the lateral displacement is investigated. Both profiles are based on the logarithmic current profiles recommended by DNV-RP-F109, however, the difference between two profiles is whether or not the wave correction is considered in the profile, i.e. whether or not the interaction between wave and current is taking into account for hydrodynamic loads. The preliminary study shows that it is beneficial for on-bottom stability of subsea cable to apply wave correction in the current profile. Sensitivity study regarding different seabed roughness and cable diameters has also been carried out.

 

 

Presenting Author: Mingxuan Hao Norwegian University of Science and Technology

Presenting Author Biography: Mingxuan Hao, a ph.d. candidate of marine department, Norwegian University of Science and Technology, the research topic is on-bottom stability of cable.

Authors:

Mingxuan Hao Norwegian University of Science and Technology
Vegard Longva SINTEF Ocean
Naiquan Ye SINTEF Ocean
Guomin Ji Department of Manufacturing and Civil Engineering
Svein Sævik Department of Marine Technology