A New Computational Fluid Dynamics Solver to Simulate Capture, Coalescence and Drainage in Coalescing Filter Media

This paper presents a method for coupling volume-of-fluid and discrete Lagrangian particle tracking methods to allow simulation oil-mist or coalescing filters, and ultimately gauge their effectiveness.The solver is built on the open-source OpenFOAM CFD libraries, which are extended to include a physically accurate model for motion of small particles, coupled with a volume-of-fluid treatment for coalesced and captured fluid. A key part of the method is accounting for particles as they collide, are intercepted by fluid or fibres and as they change from a discrete Lagrangian treatment to a volume-of-fluid treatment. Results from simulations using a portion of realistic filter geometry are used to demonstrate the intended applications of the solver. These indicate that the method is feasible, robust and that realistic behaviour of an oil-mist filter can be captured. In the future using this solver to simulate real filter geometries should lead to a better understanding of the behaviour of oil mist filters, and as a consequence, will allow filter designs to be explored through simulation in combination with experimentation