Finite Thermal Diffusivity at Onset of Convection in Autocatalytic Systems: Continuous Fluid Density

Authors

J. W. Wilder
Boyd F. Edwards, Utah State UniversityFollow
D. A. Vasquez

Document Type

Article

Journal/Book Title/Conference

Physical Review A

Volume

45

Issue

4

Publisher

American Physical Society

Publication Date

2-1992

First Page

2320

Last Page

2327

Abstract

The linear stability of exothermic autocatalytic reaction fronts is considered using the viscous thermohydrodynamic equations for a fluid with finite thermal diffusivity. For upward front propagation and a thin front, the vertical thermal gradient near the front is reminiscent of the Rayleigh-Bénard problem of a fluid layer heated from below. The problem is also similar to flame propagation, except that here the front propagation speed is limited by catalyst diffusion rather than by activation kinetics. For small density changes in a laterally unbounded system, the curvature dependence of the front propagation speed stabilizes perturbations with short wavelengths λ<λ_c, whereas long wavelengths are unstable to convection. The critical wavelengths λ_c are calculated and compared with experiments and with theoretical results for a similar problem that is driven by a Rayleigh-Taylor instability arising from a discontinuous density difference at the reaction front.

Comments

http://pra.aps.org/abstract/PRA/v45/i4/p2320_1

Published by American Physical Society in Physical Review A. Publisher PDF is available for download through the link above.

Recommended Citation

"Finite Thermal Diffusivity at Onset of Convection in Autocatalytic Systems: Continuous Fluid Density," J. W. Wilder, B. F. Edwards, and D. A. Vasquez, Phys. Rev. A 45, 2320 (1992) [25].