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Title: Elevator mode convection in flows with strong magnetic fields

Instability modes in the form of axially uniform vertical jets, also called “elevator modes,” are known to be the solutions of thermal convection problems for vertically unbounded systems. Typically, their relevance to the actual flow state is limited by three-dimensional breakdown caused by rapid growth of secondary instabilities. We consider a flow of a liquid metal in a vertical duct with a heated wall and strong transverse magnetic field and find elevator modes that are stable and, thus, not just relevant, but a dominant feature of the flow. We then explore the hypothesis suggested by recent experimental data that an analogous instability to modes of slow axial variation develops in finite-length ducts, where it causes large-amplitude fluctuations of temperature. The implications for liquid metal blankets for tokamak fusion reactors that potentially invalidate some of the currently pursued design concepts are discussed.
Authors:
;  [1]
  1. Department of Mechanical Engineering, University of Michigan-Dearborn, 48128-1491 Michigan (United States)
Publication Date:
OSTI Identifier:
22403226
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Fluids (1994); Journal Volume: 27; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AMPLITUDES; CONVECTION; DUCTS; EXPERIMENTAL DATA; FLUCTUATIONS; HYPOTHESIS; INSTABILITY; LIQUID METALS; MAGNETIC FIELDS; MATHEMATICAL SOLUTIONS; THERMONUCLEAR REACTORS; THREE-DIMENSIONAL CALCULATIONS; TOKAMAK DEVICES; WALLS