Simulation of the spherical orientation probability distribution of paper fibers in an entire suspension using immersed boundary methods
Artikel i vetenskaplig tidskrift, 2016

A numerical model based on the Fokker–Planck equation for studying the orientation of paper fibers in a suspension is presented. The model is implemented in a finite volume framework. The rotational operators are discretized on a triangulated half sphere and the spatial operators are discretized on a Cartesian octree grid, where internal walls are handled with immersed boundary methods. Transient solutions of the two dimensional fiber orientation distribution are computed in the entire fluid domain. This is in contrast to earlier approaches that either only compute along streamlines or one dimensional projected orientations. The fibers are assumed to have negligible inertia and thus to follow the fluid perfectly and to be evenly distributed. A head-box geometry relevant for paper forming is used to exemplify the usefulness of the method. The influence of translational and rotational diffusion is included in the presented method.

Paper making

Fiber suspension

Fiber orientation probability density

Immersed boundary method


Tomas Johnson

Pekka Röyttä

Fredrik Edelvik

Journal of Non-Newtonian Fluid Mechanics

0377-0257 (ISSN)

Vol. 229 1-7


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Strömningsmekanik och akustik