# Drag forces on a semisubmersible platform column for different corners curvature radius

### Resumen

In an early design stage of a floating production system, the definition of certain important characteristics are required, such as production or storage capacities, and others related to the strength of the floating system hull against waves, wind and current forces. Based on these, the dimensions of the platform are derived, and in the particular case of semi-submersible platforms and tensioned leg platforms the dimensions of their columns, as well as the curvature radius of the column corner. This work focuses on the calculation of marine current drag forces on a large dimension column (17.2 m width) considering a range of curvature radius on corners. Reducing marine current forces is a very important issue in floating oil production platforms with large dimensions columns (as semisubmersibles or tension leg platforms). In order to capture turbulence effects three-dimensional Reynolds-Averaged Navier-Stokes (RANS) simulations are developed using k-ω Shear Stress Transport (SST) viscous model. Even for small current velocities, high Reynolds numbers are presented due to the large column dimensions. Results show that drag forces has a fast decay for radius from 1 m to 1.5 m, for greater radius drag forces presents small changes. Additionally, flux behavior is analyzed; the associated vertical flux that modifies the horizontal behavior about the vertical level and the flux trace behavior in function of Reynolds number.### Citas

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