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Artikel

Active control of a global thermocapillary instability

Författare: Shiomi, J., Amberg, G.A.
Dokumenttyp: Artikel
Tillstånd: Publicerad
Tidskrift: Phys. Fluids
Volym: 14   3039
År: 2002

Abstract

Active control was applied to oscillatory thermocapillary flow in an open cylindrical container filled with Silicone oil. Thermocapillary convection was driven by imposing a radial temperature gradient on a flat free surface. This is an extension of the previous work by Shiomi $\it$. \cite who applied proportional feedback control by locally heating the surface at a single position using the local temperature signal at a different position fed back through a simple algorithm. Although significant attenuation of the oscillation was detected, an uncertainty remained if global stabilization was achieved. In the present paper, two sensor/heater pairs were installed to achieve the global suppression of the oscillation. Successful global stabilization of the oscillation was achieved in a range of Marangoni number, with the best performance in the weakly nonlinear regime. Using a reliable temperature measurement method, quantitative analysis is carried out to quantify the performance of the control. The optimal values of gain and relative position of sensor/heater pairs were identified.