Numerical investigation of upstream cylinder flow and characterization of forming fabrics
Artikel i vetenskaplig tidskrift, 2019

In this work, the fundamentals of upstream flow over cylinders and forming fabrics are investigated, and measures for characterization of fabrics are proposed. Two-dimensional flow over one cylinder, two cylinders, and one and two rows of cylinders, are analysed numerically. By studying different configurations and various Reynolds numbers, the upstream flow features are characterized. It is concluded that cylinders have a short range of upstream flow impact, shortest for rows of cylinders with small spacings. For Re∈[10,80], the Reynolds number dependency is weak. It is shown that a downstream row positioned in tandem has negligible impact on the upstream flow, while a displaced second row influences the upstream flow if the spacing in the first row is larger than one diameter. The pressure drop required to drive the flow over the cylinders depends non-linearly on the porosity of the configuration. Flow measures of the upstream flow are proposed, which in addition to the volume flow per area are used to characterize fabric flow properties. The conclusions from the cylinder study also hold for industrial fabrics, and it can be explained how properties of the fabric influence the final paper. The wave-length of flow periodicity is studied in relation to drainage marking. This study demonstrates that simulations can greatly improve pure experimental-based fabric characterization.

forming fabric parameters

forming fabrics

flow uniformity

upstream cylinder flow

drainage marking

Författare

Gustav Kettil

Chalmers, Matematiska vetenskaper, Tillämpad matematik och statistik

Andreas Mark

Chalmers, Mekanik och maritima vetenskaper, Strömningslära

Stiftelsen Fraunhofer-Chalmers Centrum för Industrimatematik

Kenneth Wester

Albany International

Mats Fredlund

Stora Enso Research Centre

Fredrik Edelvik

Stiftelsen Fraunhofer-Chalmers Centrum för Industrimatematik

Nordic Pulp and Paper Research Journal

0283-2631 (ISSN)

Vol. 34 3 371-393

Ämneskategorier

Geofysisk teknik

Teknisk mekanik

Strömningsmekanik och akustik

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

DOI

10.1515/npprj-2018-0072

Mer information

Skapat

2019-09-11