Europhys. Lett.
Volume 69, Number 5, March 2005
Page(s) 746 - 752
Section Electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics
Published online 02 February 2005
Europhys. Lett., 69 (5), pp. 746-752 (2005)
DOI: 10.1209/epl/i2004-10417-9

Control of chemo-hydrodynamic pattern formation by external localized cooling

D. A. Bratsun1, Y. Shi2, K. Eckert2 and A. De Wit1

1  Service de Chimie Physique and Center for Nonlinear Phenomena and Complex Systems, CP 231, Université Libre de Bruxelles - 1050 Brussels, Belgium
2  Institute for Aerospace Engeneering, Dresden University of Technology 01062 Dresden, Germany

received 27 September 2004; accepted in final form 3 January 2005
published online 2 February 2005

Chemo-hydrodynamic patterns can form in a chemical two-layer system in a Hele-Shaw cell when each fluid contains separately a reactant of an exothermic neutralization reaction. When one reactant diffuses through the interface, the coupling between the chemical reaction and buoyancy-driven flows gives rise to complex spatio-temporal fingering near the interface. We show both experimentally and theoretically that such chemistry-driven fingering and its characteristics can be precisely controlled by external cooling applied locally along the sidewalls of the reactor. This control process gives a bright example of cooperative phenomena between chemistry and hydrodynamics and offers promising technological applications.

47.70.Fw - Chemically reactive flows.
47.70.-n - Reactive, radiative, or nonequilibrium flows.
47.20.Bp - Buoyancy-driven instability.

© EDP Sciences 2005