Abonnement à la biblothèque: Guest
Portail numérique Bibliothèque numérique eBooks Revues Références et comptes rendus Collections
Journal of Porous Media
Facteur d'impact: 1.752 Facteur d'impact sur 5 ans: 1.487 SJR: 0.43 SNIP: 0.762 CiteScore™: 2.3

ISSN Imprimer: 1091-028X
ISSN En ligne: 1934-0508

Volume 24, 2021 Volume 23, 2020 Volume 22, 2019 Volume 21, 2018 Volume 20, 2017 Volume 19, 2016 Volume 18, 2015 Volume 17, 2014 Volume 16, 2013 Volume 15, 2012 Volume 14, 2011 Volume 13, 2010 Volume 12, 2009 Volume 11, 2008 Volume 10, 2007 Volume 9, 2006 Volume 8, 2005 Volume 7, 2004 Volume 6, 2003 Volume 5, 2002 Volume 4, 2001 Volume 3, 2000 Volume 2, 1999 Volume 1, 1998

Journal of Porous Media

DOI: 10.1615/JPorMedia.v6.i3.30
11 pages

On Stationary and Oscillatory Modes of Flow Instability in a Rotating Porous Layer during Alloy Solidification

Daniel N. Riahi
School of Mathematical and Statistical Science, University of Texas Rio Grande Valley, Edinburg, Texas 78539, USA


Linear flow instability due to either stationary (nonoscillatory) or oscillatory modes of disturbances in a horizontal porous layer during alloy solidification is investigated under an external constraint of rotation. The porous layer, which is referred to as a mushy layer in the solidification literature, is assumed to rotate about the vertical axis at a constant angular velocity. The investigation is based on the model of Amberg and Homsy (1993) and under the limit of large Stefan number as treated by Anderson and Worster {1996) in the absence of the rotational constraint. An oscillatory mode was found for the first time to dominate over the stationary mode and over several other detected oscillatory modes at the onset of motion. In contrast to the stationary mode, the most critical oscillatory mode was uncovered to reduce the tendency for chimney formation in the rotating porous layer. In engineering applications, presence of these chimneys is undesirable since their presence can produce imperfections that reduce the quality of the solidified material. Results of the stability analyses indicate both stabilizing and destabilizing effects of the Coriolis force on the flow in the porous layer. For example, the effects of the Coriolis force can be stabilizing in the sense that the critical value of the Rayleigh number at the onset of motion increases with the rotation rate, while the effects of the Coriolis force can be destabilizing in the sense that the oscillatory instability is enhanced in the presence of rotation.

Articles with similar content:

Flow Instabilities in a Horizontal Dendrite Layer Rotating about an Inclined Axis
Journal of Porous Media, Vol.8, 2005, issue 3
Daniel N. Riahi
Inertial Effects on Rotating Flow in a Porous Layer
Journal of Porous Media, Vol.10, 2007, issue 4
Daniel N. Riahi
Thermal Modulation of Raleigh-Benard Convection in a Sparsely Packed Porous Medium
Journal of Porous Media, Vol.10, 2007, issue 2
Beer S. Bhadauria
Special Topics & Reviews in Porous Media: An International Journal, Vol.5, 2014, issue 2
Sunil, Amit Mahajan, Shalu Choudhary
Moderate Time Scale Linear Stability of Moderate Stefan Number Convection In Rotating Mushy Layers
Journal of Porous Media, Vol.5, 2002, issue 2
Saneshan Govender, Peter Vadasz