MARIN’s CFD Development Team and its partners further advance the renowned viscous flow code. The renowned viscous flow code ReFRESCO, developed by MARIN and various international collaborators, has achieved an important milestone, as the latest version 2023.1 is unveiled.
ReFRESCO is used in many research and consultancy projects, calculating forces on ships and offshore and renewable energy structures in combined wind, wave and current conditions. In addition to environmental forces, propulsors can be computed from actuator disc models via boundary element methods to full viscous flow simulations. ReFRESCO has many other capabilities such as moving bodies, turbulence models, free-surface, roughness and transition models, to name but a few.
developed since 2005
Over the last decade significant effort has been given to free surface modelling, which involves the simulation of floating bodies with water and air, and the wavy surface in between. The latest issue that was addressed was numerical ventilation, a well-known problem in the maritime CFD community, where there is no scientific agreement on why it is happening, or what can solve it. Numerical ventilation – the non-physical trapping of a very thin layer of air along the hull - usually only occurs in a complex flow around a ship’s hull for example.
Overset grid setup of propeller-rudder test case
unsteady simulation of the BB-2 submarine model
The animation shows an unsteady simulation of the BB-2 submarine model with a rotating propeller carried out using scale-resolving simulations. It depicts iso-contours of instantaneous wall-shear stress on the submarine body and non-dimensional axial velocity on the centreplane of the numerical domain. Only the aft part of the geometry is resolved and the effect of the turbulent boundary layer on the upstream part of the hull is modelled using a combination of prescribed average inflow velocity and synthetic turbulence generation.