DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Comments on the numerical investigation of Rayleigh and Marangoni convection in a vertical circular cylinder

Wagner, Claus and Friedrich, Rainer and Narayanan, Ranga (1994) Comments on the numerical investigation of Rayleigh and Marangoni convection in a vertical circular cylinder. Physics of Fluids, 6, pp. 1425-1433. American Institute of Physics (AIP). doi: 10.1063/1.868257. ISSN 1070-6631.

[img] PDF - Published version

Official URL: https://aip.scitation.org/doi/pdf/10.1063/1.868257


Convection in a cylindrical container was simulated with a three dimensional, time-dependent code. For the case of purely Rayleigh convection, a completely rigid cylinder with adiabatic vertical walls and conducting horizontal walls was considered. The calculations showed that the individual velocity components could be in a transient state, while the total heat transfer was steady. This occurred in cases where the maximum azimuthal component of velocity was very small in magnitude, in comparison to the other two components, and this component decreased in time. On the other hand, the total kinetic energy along with the heat transfer reached a steady value. Consequently the present results have been shown to be at variance with the calculations of Neumann [I. Fluid Mech. 214, 559 (1990)]. Marangoni convection was modeled with a free flat surface on the upper side, assuming the superimposed second layer to be passive. The numerically obtained critical Marangoni numbers and flow patterns were compared favorably to earlier results from linearized stability. In addition, flow structural changes for supercritical Marangoni numbers were illustrated. Interestingly, axisymmetric disturbances led to nonsymmetric bifurcation diagrams, but three-dimensional disturbance calculations led to symmetry in the bifurcation plots. Another very interesting result was the observed transition from three-dimensional to two-dimensional patterns as the Marangoni number was increased. Large computational requirements precluded a detailed parametric study. The special case of Prandtl number equal to 6.7 (corresponding to water), and in the case of Marangoni convection, a surface Biot number of unity was assumed.

Item URL in elib:https://elib.dlr.de/193991/
Document Type:Article
Title:Comments on the numerical investigation of Rayleigh and Marangoni convection in a vertical circular cylinder
AuthorsInstitution or Email of AuthorsAuthor's ORCID iDORCID Put Code
Wagner, ClausUNSPECIFIEDhttps://orcid.org/0000-0003-2273-0568UNSPECIFIED
Narayanan, RangaUniversity of FloridaUNSPECIFIEDUNSPECIFIED
Journal or Publication Title:Physics of Fluids
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In ISI Web of Science:Yes
Page Range:pp. 1425-1433
Publisher:American Institute of Physics (AIP)
Keywords:Rayleigh-Benard convection, Marangoni convection, flow simulation, instability
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Transport
HGF - Program Themes:Rail Transport
DLR - Research area:Transport
DLR - Program:V SC Schienenverkehr
DLR - Research theme (Project):V - RoSto - Rolling Stock
Location: Göttingen
Institutes and Institutions:Institute for Aerodynamics and Flow Technology > Ground Vehicles
Deposited By: Wagner, Prof. Dr.-Ing. Claus
Deposited On:30 Mar 2023 15:42
Last Modified:30 Mar 2023 15:42

Repository Staff Only: item control page

Help & Contact
electronic library is running on EPrints 3.3.12
Website and database design: Copyright © German Aerospace Center (DLR). All rights reserved.