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Artikel

Effect of fibres on hydrodynamic stability in a curved rotating channel

Författare: Kvick, M., Lundell, F., Prahl Wittberg, L., Söderberg, D.
Dokumenttyp: Konferens
Tillstånd: Publicerad
Tidskrift: 8th International Conference on Multiphase Flow (ICMF), Jeju, Korea (2013)
Volym:   
År: 2013

Abstract

Experiments and a linear stability analysis are performed for a range of flow velocities and rotation rates in a curved and rotating, high aspect ratio, rectangular, channel. The study is carried out in order to investigate the effect of Nano-Fibrillated Cellulose (NFC) on the hydrodynamic stability. In the experiments, the structures in the flow are visualised and images are acquired at a downstream position. In the linear stability analysis, the presence of fibres is modelled as an orientation dependent stress tensor, where the orientation is calculated based on Jeffery’s equations. A clear stabilisation is found when NFC is present, both in the experiments and in the theoretical work. However, this stabilisation is less than predicted by the effective viscosity. Moreover, the transient growth is found to a greater extent to be affected by the presence of fibres compared to the stabilisation, while the spanwise wavenumber is more or less unaffected.