Macroscopic filter modelling based on computational fluid (CFD)

U. Heck*, M. Becker, DHCAE Tools GmbH, Germany

Filter applications are important for the chemical, automotive and domestic appliances industries. DHCAE Tools developed a solver for the simulation of filters based on the open source CFD library OpenFOAMĀ®. In this presentation DHCAE Tools presents new extensions in the filter modelling, in particular a Fluid-structure interaction coupling (FSI) with the open-source structural solver CalculiX and a meso scaled approach to model growing filter cake structures.

The numeric models describe the interactions of discrete particles in a continuous flow with thin-walled, porous media on a macroscopic scale.

Figure 1 - Clogged filter bag and streamlines.

An iterative algorithm was implemented to simulate the filter loading. Particles are injected as Lagrangian particles and tracked with a local time stepping (LTS) approach. With the local particle concentration, the non-uniform resistance of the filter is calculated. The pressure drop caused by the filters is calculated with the Darcy-Forchheimer Law.

New flow conditions have been implemented, for example to deal with the damping of the turbulence across the filter baffle, the orientation of the velocity field and the correct calculation of the pressure drop. The macro scale modelling approach allows the simulation of depth filter applications as well as surface filters with a filter cake up-building. A new meso-scale model allows geometrically growing filter cakes with complex porous structures. A steady state particle tracking in combination with the SIMPLE algorithm for the flow field calculation result in...

Session: F5 - Filter Media - Numerical Methods for Optimized Media Design II
Day: 14 March 2018
Time: 16:45 - 18:00 h

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