CFD tools and adapted methodologies for Marine and Offshore Engineering projects

Abstract

Computational Fluid Dynamics (CFD) tools have progressed greatly in the past decades in such a manner that they have become a recurring tool during the workflow of an engineering project. In the specific case of Marine and Offshore Engineering, these tools are more and more used to predict forces on structures with a very detailed level of precision, to optimize hull forms to conceive more efficient and environmentally friendly designs and also to reassure structural engineers with respect to the assumptions made during complex engineering problems. In this article several examples of how these tools and methodologies have been employed in the design process of Marine and Offshore structures will be presented. Validations compared to tank tests and wind tunnels will be presented for damping coefficients, green water impact, aerodynamic coefficients and non-linear wave loading studies. Throughout these examples it will be shown how the need of dedicated tools/methodologies is necessary in order to efficiently use the CFD tools during the Naval and Offshore design process. Very often, distinct phenomena need to be modeled in order to correctly apprehend the complexity of the flows. To do so, coupling distinct approaches is sometimes necessary: CFD solver to a potential one for instance. In the paragraphs below four examples are illustrated: nonlinear wave loading computations, damping coefficients computation, aerodynamics winf loads estimation on complex topside structures, and prediction of green water impact on a FPSO.

An Investigation on the Vortex Effect of a CALM Buoy under Water Waves Using Computational Fluid Dynamics (CFD)

“…The authors opined that to establish the dampening of the buoy's oscillations and acquire the natural periods, decay tests were necessary as well as the mooring system's dynamics, and the consequent dampening which has substantial impact on the buoy's motions. Different CFD studies include validation studies on CALM buoys presented by various researchers [41][42][43], application using different CFD modelling methods for fluid studies [44][45][46] and coupled models [46][47][48]. Figure 2 shows a typical CALM buoy in the Baltic Sea offshore Lithuania installed by SOFEC [49].…”