Multiphase flows

Our state-of-the-art fluid flow solver IPS IBOFlow features a novel and very robust volume of fluids (VoF) module for handling multiphase flows. The combination of moving, interacting, deforming bodies and  free surface flows or dispersed phases is one of the areas where IPS IBOFlow is outstanding. Many industrial problems involve these types of flows and new cases are continuously being simulated in IPS IBOFlow.

Movie: The rear of a Volvo C30 is dipped in a bath of water to predict if air-bubbles will be present during the E-coating process.

Details

IPS 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 IPS 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.

Comparison of a stationary flat bead sealing application , experiment (left) and simulation (right).
Comparison of a stationary flat bead sealing application , experiment (left) and simulation (right).

Application areas

The VOF module has been successfully used for many different applications such as simulation of sealing spray, glue application, solder jetting and the peroxide bath in a filling machine.

 

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