Volume of Fluids Module in IPS IBOFlow
Our state-of-the-art fluid flow solver IPS IBOFlow has been extended with a novel and very robust volume of fluids (VoF) module for handling multiphase flows.
IBOFlow (Immersed Boundary Octree Flow Solver) is an incompressible, segregated Navier-Stokes solver. It is based on a collocated finite volume discretization on a Cartesian octree grid that is dynamically refined and coarsened. Moving and interacting objects are efficiently handled through unique immersed boundary methods.
The implementation of volume of fluids (VoF) in collocated finite volume solvers is challenging with well known problems with the pressure and velocity coupling. In the literature several different remedies are described for example by utilizing under relaxation and putting constraints on the mesh.
The VoF module in IBOFlow is fully stable, requires no under relaxation, no correction of the Rhie and Chow interpolation, and allows for an adaptive mesh at and along the interface.
The result is a robust and very efficient implementation.
To keep a sharp interface a hybrid CICSAM scheme has been implemented. Surface tension is included according to the CSF model by Brackbill et al. To simulate small scale water droplets with radius less than one millimeter in air is challenging and many existing commercial solvers exhibit stability problems. In IBOFlow water droplets of radius ten micrometer in air have been verified to be fully stable.
The VOF module has been successfully used for different applications such as simulation of electro-coating, sealing spray and the peroxide bath in a filling machine.
Simulation of a e-coat of a car part using the VOF module in IBOFlow.
Simulation of a rotating mixer using the VOF module in IBOFlow. The velocities are shown on the free surface.
© 2013 Fraunhofer - Chalmers Centre