On the structure of the floating zone in melting

Da Riva de la Cavada, Ignacio and Meseguer Ruiz, José (1978). On the structure of the floating zone in melting. "Acta Astronautica", v. 5 (n. 9); pp. 637-653. ISSN 0094-5765.

Description

Title: On the structure of the floating zone in melting
Author/s:
  • Da Riva de la Cavada, Ignacio
  • Meseguer Ruiz, José
Item Type: Article
Título de Revista/Publicación: Acta Astronautica
Date: 1978
Volume: 5
Subjects:
Faculty: E.T.S.I. Aeronáuticos (UPM)
Department: Vehículos Aeroespaciales [hasta 2014]
Creative Commons Licenses: Recognition - No derivative works - Non commercial

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Abstract

Floating zone melting is used in crystal growth and purification of high melting materials. The use of a reduced gravity environment will remove the constraint imposed on the length of the zone by the hydrostatic pressure. The equilibrium of the fioatmg zone may involve, (1)Hydrostatic forces, when the zone rotates as a whole. (2)Convective driving forces, when the zone is stationary but fluid property gradients appear.(3) Hydrodynamic forces, when some parts of the zone are set into motion with respect to others. The last effects are considered in this paper. The flow pattern of a floating zone held between two discs in relative motion is complicated, and thence the solution of the problem is difficult even assuming a constant property-newtonian liquid Nevertheless, when a small parameter appears m the problem, the complete flow field can be split into zones where simple solutions are found. To illustrate this approach, the spin up from rest of an initially cylindrical floating zone is considered with detail. Here the small parameter is the time elapsed from the impulsive starting of motion. Since the problem which has been considered, as well as some others which can be tackled by use of similar methods, concern the viscous layer close to either plate, they can be simulated experimentally in the ground laboratory with short floating zones. Procedures to produce these zones are indicated.

More information

Item ID: 13747
DC Identifier: http://oa.upm.es/13747/
OAI Identifier: oai:oa.upm.es:13747
Deposited by: Biblioteca ETSI Aeronauticos
Deposited on: 22 Oct 2012 08:37
Last Modified: 21 Apr 2016 13:06
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