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Utah State University

CONVECTION

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Full-Text Articles in Physics

Chemical Wave Propagation In Hele-Shaw Cells And Porous Media, D. A. Vasquez, J. W. Wilder, Boyd F. Edwards Mar 1996

Chemical Wave Propagation In Hele-Shaw Cells And Porous Media, D. A. Vasquez, J. W. Wilder, Boyd F. Edwards

All Physics Faculty Publications

Chemical waves induce density gradients in fluids which may lead to convection. This paper studies the convective effects on chemical waves propagating in porous media or in fluids confined between two parallel vertical walls. Chemical waves in the iodate–arsenous acid system are modeled with a one variable reaction‐diffusion equation. The fluid flow is modeled using Darcy’s law. A linear stability analysis on convectionless fronts shows a transition to convection. The full nonlinear equations describing the convective front are solved numerically on a vertical slab. Convective fronts propagate faster than convectionless fronts. Near the onset of convection, the fronts are raised …


Hydrodynamic Instability Of Chemical Waves, D. A. Vasquez, J. W. Wilder, Boyd F. Edwards Oct 1992

Hydrodynamic Instability Of Chemical Waves, D. A. Vasquez, J. W. Wilder, Boyd F. Edwards

All Physics Faculty Publications

We present a theory for the transition to convection for flat chemical wave fronts propagating upward. The theory is based on the hydrodynamic equations and the one‐variable reaction‐diffusion equation that describes the chemical front for the iodate–arsenous acid reaction. The reaction term involves the reaction rate constants and the chemical composition of the mixture. This allows the discussion of the effects of the different chemical variables on the transition to convection. We have studied perturbations of different wavelengths on an unbounded flat chemical front and found that for wavelengths larger than a critical wavelength (λ≳λc) the perturbations grow …