Session: 12-01-01 Hydrodynamics, Seakeeping and Global Performance

Paper Number: 78835

78835 - Wave-Induced Loads Acting on Monopile Configurations Considering Wake Effects 

A comparative study investigated hydrodynamic loads acting on two cylinders placed one behind the other. First, experimentally measured loads on a single cylinder in focused waves were determined and used to validate the associated numerical calculations. Computed and measured forces agreed favorably. Subsequently, two scenarios were considered. One scenario dealt with both cylinders in that loads acting on the upstream and downstream cylinder were calculated directly. This accounted for the effect of the wake on the loads on the rear cylinder. In the other scenario, both cylinders were removed, and the loads were determined on the basis of the Morison equation. Employing unsteady Reynolds-averaged Navier–Stokes (URANS) equations solver coupled with the volume of fluid (VOF) method, flow velocities were computed at different height positions corresponding to the location of the missing cylinders, and these velocities were used in the Morison equation. The flow accelerations were derived from the velocities at the different height positions using the central difference scheme. This provided a way to address the question of whether the Morison equation is able to provide useful load predictions even in the presence of wake effects. Effects of the wake of the front cylinder on the loads acting on the rear cylinder were computed and analyzed.

Presenting Author: Michael Thome Institute of Ship Technology, Ocean Engineering and Transport Systems

Authors:

Michael Thome Institute of Ship Technology, Ocean Engineering and Transport Systems
Bettar Ould El Moctar Institute of Ship Technology, Ocean Engineering and Transport Systems
Thomas Erling Schellin Institute of Ship Technology, Ocean Engineering and Transport Systems