On a multiscale approach for filter efficiency simulations


O. Iliev, Z. Lakdawala, and G. Printsypar, On a multiscale approach for filter efficiency simulations, J. Comput. Math. Appl. 67:2171-2184 (2014)


O. Iliev, Z. Lakdawala, and G. Printsypar


Multiscale approach, filter efficiency




Filtration in general, and the dead end depth ltration of solid particles out of uid in particular, is intrinsic multiscale problem. The
deposition (capturing of particles) essentially depends on local velocity, on microgeometry (pore scale geometry) of the ltering medium
and on the diameter distribution of the particles. The deposited (captured) particles change the microstructure of the porous media what
leads to change of permeability. The changed permeability directly influences the velocity eld and pressure distribution inside the lter
element. To close the loop, we mention that the velocity inuences the transport and deposition of particles. In certain cases one can evaluate
the ltration eciency considering only microscale or only macroscale models, but in general an accurate prediction of the ltration eciency
requires multiscale models and algorithms. This paper discusses the single scale and the multiscale models, and presents a fractional time
step discretization algorithm for the multiscale problem. The velocity within the lter element is computed at macroscale, and is used as
input for the solution of microscale problems at selected locations of the porous medium. The microscale problem is solved with respect
to transport and capturing of individual particles, and its solution is postprocessed to provide permeability values for macroscale computations. Results from computational experiments with an oil lter are presented and discussed.


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