With the increasing size of offshore structures, wind loads are becoming more and more important when designing vessels for operational conditions. For some locations, the wind may be the predominant load factor.
There are several ways to determine the wind loads of typical vessels. A dramatic growth in computing power has meant that Computational Fluid Dynamics (CFD) has become increasingly capable of calculating the wind load coefficients. This article discusses the possibilities of using CFD to determine wind loads.
Within the WINDLOAD Joint Industry Project, a semi-submersible platform and a Floating Production Storage and Offloading (FPSO) unit have been tested in three different wind tunnel facilities and CFD computations were performed by different companies.
The colours are used to indicate the pressure coefficient, with red indicating a high pressure and blue a low pressure region. Furthermore, regions with high vorticity (rotation of air) are shown as isosurfaces. From video material, regions are visible where vortices are shed from the turret and helideck, which result in unsteady wind flow behind these structures.