Marine CFD basics
With Computational Fluid Dynamics (CFD) a virtual representation of any type of phenomena related to fluid and air flows can be made and is widely used for maritime applications. Marine CFD experts are specialized in setting up numerical models, evaluate and apply appropriate solving methods and present simulations in formats that can be used in the analysis of a structure. Virtual physical models, either in steady-state or transient, are created and deliver a visualization as well as numerical results in all kinds of fluid dynamics situations. With recent developments in increased computational power and dedicated software it is possible to make Marine CFD calculations providing insight in all kind of applications within the maritime domain.
In an early design stage marine CFD modeling gives insight in all kind of flow related questions before any prototype or scale testing is done. A thorough understanding of the physics of the phenomena is crucial, as well as relating the numerical results with any later performed experiments in e.g. a towing tank. Of particular interests are cases in which the interaction of the fluid with a structure (piles at sea, ship shell structures, storage tanks with fuel) plays a role. Here marine CFD is the virtual towing tank making it possible to test a ship, pump or any other construction in an early design stage. Design changes can be easily fed back into the CFD model to be evaluated and create immediate insight. Also effects that cannot be seen during model tests can be visualized through CFD-modeling. This makes marine CFD a multi-purpose tool which can be used for a wide range of studies. Marine CFD can be performed against much lower costs and much faster than traditional model tests in for example towing tanks.
Marine CFD: Hydrodynamics and aerodynamics assessments
Hydrodynamics deals with water flow around the ship, propellers, rudders and bilge keels. Aerodynamics deal with the airflow around the ship structure above the water level.
With such assessments various aspects of ship resistance and loading strategies influencing the propulsion efficiency can be evaluated. In addition aerodynamic assessments could be useful to model flow of exhaust gases and gas dispersions in confined space for defining a ventilation strategy and performing a fire hazard analysis.
Marine CFD: Multi Flow and Multi phase Behaviour
Marine CFD calculations can be used to assess multi fluid flow (different densities) behaviour and to simulate effects with multi phase (gas, liquid, solid) behaviour. For gas pumping or LNG-container transport effects at condensation are important design parameters.
Marine CFD in dredging applications
For dredging multi fluid flow modelling may be required to assess complex pumping strategies or to determine mixing, stirring and sedimentation processes. With multi phase flow analysis in piping systems and nozzles can be analysed. For certain forms of dredging the interaction of a (multiphase ) flow with the sediment (solid) needs to be better understood and can be visualized.. All processes that play an important role in dredging can be better understood by using marine CFD.