Measurement and Analysis of Flow of Concentrated Fiber Suspensions through a 2-D Sudden Expansion Using UVP
Artikel i vetenskaplig tidskrift, 2013

The ultrasound velocity profiling technique (UVP) was used to study flow structures after a two-dimensional (2-D) 1: 11 sudden expansion of pulp fiber suspensions at varied average velocities (1-2.2 m/s) and concentrations (1.8 and 2.8 wt %). One advantage of studying jet geometry is the potential to investigate the main flow structures away from walls. Measurements done at the same percent of the total jet length, at constant concentration, show that an increase in flow rate gave a faster decrease in centerline velocity and a quicker increase in jet width. Increasing the concentration, at the same jet length, the centerline velocity was more stable and the width of the mixing layer increased more rapidly. Comparisons with CFD simulations in the laminar regime, using the Bingham plastic model, show that the main flow structures were captured if the yield stress used in the simulations is approximately 20% of the measured using a rheometer.

jet

cfd

piv

rheology

suspensions

lda

near-wall

papermaking

fluidization

fibers

fluid mechanics

pulp suspensions

velocity

multiphase flow

Författare

Julia Claesson

Chalmers, Kemi- och bioteknik, Kemisk apparatteknik

Anders Rasmuson

Wallenberg Wood Science Center (WWSC)

Chalmers, Kemi- och bioteknik, Kemisk apparatteknik

J. Wiklund

Swedish Institute for Food and Biotechnology

T. Wikstrom

Metso Paper

AICHE Journal

0001-1541 (ISSN) 1547-5905 (eISSN)

Vol. 59 3 1012-1021

Ämneskategorier

Kemiteknik

DOI

10.1002/aic.13881