Hydrodynamic Instability of Chemical Waves
Hydrodynamic Instability of Chemical Waves
复制标题
化学波的流体动力学不稳定性
DOI：
10.1063/1.464192
复制
发表时间：
1993
影响因子：
4.4
通讯作者：
Boyd F. Edwards
中科院分区：
文献类型：
--
作者：
D. Vasquez;J. Wilder;Boyd F. Edwards
我们提出了一种向上传播的平坦化学波锋面向对流过渡的理论。该理论基于流体动力学方程和描述碘酸-砷酸反应化学前沿的单变量反应-扩散方程。反应项包括反应速率常数和混合物的化学成分。这样就可以讨论不同的化学变量对向对流转变的影响。我们在无界平面化学前沿研究了不同波长的微扰，发现波长大于临界波长（λ > λc）时，微扰随时间增长，而波长较小时，微扰减小。临界波长不仅取决于未反应流体和反应流体之间的密度差，还取决于化学前沿的速度和厚度。我们提出了一种向上传播的平坦化学波锋面向对流过渡的理论。该理论基于流体动力学方程和描述碘酸-砷酸反应化学前沿的单变量反应-扩散方程。反应项包括反应速率常数和混合物的化学成分。这样就可以讨论不同的化学变量对向对流转变的影响。我们在无界平面化学前沿研究了不同波长的微扰，发现波长大于临界波长（λ > λc）时，微扰随时间增长，而波长较小时，微扰减小。临界波长不仅取决于未反应流体和反应流体之间的密度差，还取决于化学前沿的速度和厚度。
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 in time, while for smaller wavelengths the perturbations diminish. The critical wavelength depends not only on the density difference between the unreacted and reacted fluids, but also on the speed and thickness of the chemical front.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 in time, while for smaller wavelengths the perturbations diminish. The critical wavelength depends not only on the density difference between the unreacted and reacted fluids, but also on the speed and thickness of the chemical front.