Control of oscillatory thermocapillary convection with local heating
2006 (English)In: Journal of Crystal Growth, ISSN 0022-0248, E-ISSN 1873-5002, Vol. 286, no 2, 502-511 p.Article in journal (Refereed) Published
In this experimental work, a proportional feedback control was applied to attenuate an oscillatory thermocapillary flow in an open cylindrical container (annular configuration) filled with silicon oil with high Prandt1 number (Pr = 14 at 25 degrees C). The control was realized by locally heating the free surface with two point source heaters strategically positioned in different azimuthal positions. The heaters were actuated using the local temperature signals fed back from paired sensors. It is suggested that the shortcoming of the control performance accompanied with the amplification of the harmonic frequency components is due to the coupling of the fundamental and the harmonic modes caused by the local control. A remedy is demonstrated to validate the suggestion, where the coupling can be attenuated by increasing the azimuthal length of the actuation region.
Place, publisher, year, edition, pages
2006. Vol. 286, no 2, 502-511 p.
annular configuration, feedback control, thermocapillary instability, si crystal-growth, liquid bridge, nonlinear control, half-zone, vibration, instability, fields
IdentifiersURN: urn:nbn:se:kth:diva-15382DOI: 10.1016/j.jcrysgro.2005.10.117ISI: 000234758300046ScopusID: 2-s2.0-29344458276OAI: oai:DiVA.org:kth-15382DiVA: diva2:333423
QC 201005252010-08-052010-08-05Bibliographically approved