The dynamics of A+B-->C fronts in horizontal solution layers can be influenced by buoyancy-driven convection as soon as the densities of A, B, and C are not all identical. Such convective motions can lead to front propagation even in the case of equal diffusion coefficients and initial concentration of reactants for which reaction-diffusion (RD) scalings predict a nonmoving front. We show theoretically that the dynamics in the presence of convection can in that case be predicted solely on the basis of the knowledge of the one-dimensional RD density profile across the front.
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http://dx.doi.org/10.1103/PhysRevLett.101.084503 | DOI Listing |
Heliyon
January 2025
Department of Mathematics, University of Dhaka, Dhaka 1000, Bangladesh.
This study analyzes the influences of surface reactions on the natural convective flow, temperature, and oxygen concentration distributions in vertically placed multilayered cavities. A mathematical model for this problem is formulated with proper boundary conditions. At first, the governing equations are made dimensionless using the variable transformations.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Nonlinear Physical Chemistry Unit, Service de Chimie Physique et Biologie Théorique, Université libre de Bruxelles (ULB), CP 231 - Campus Plaine, 1050 Brussels, Belgium.
Exotic dynamics, previously associated only with reactions involving complex kinetics, have been observed even with simple bimolecular reactions A + B → C, when coupled with hydrodynamical flows. Numerical studies in two-dimensional reactors have shown that oscillatory dynamics can emerge from an antagonistic coupling between chemically-driven buoyancy and Marangoni convective flows, induced by changes in density and surface tension, respectively, as the reaction occurs. Here, we investigate reactions increasing both surface tension and density, leading to a cooperative coupling between the flows and show how, in this configuration, buoyancy-driven contribution dampens spatio-temporal oscillations of concentration.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2024
Department of Chemistry, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
In the presence of appropriate substrates, surface-anchored enzymes can act as pumps and propel fluid through microchambers. Understanding the dynamic interplay between catalytic reactions and fluid flow is vital to enhancing the accuracy and utility of flow technology. Through a combination of experimental observations and numerical modeling, we show that coupled enzyme pumps can exhibit flow enhancement, flow suppression, and changes in the directionality (reversal) of the fluid motion.
View Article and Find Full Text PDFPLoS One
July 2024
Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, United Kingdom.
The existence of temperature gradients within eukaryotic cells has been postulated as a source of natural convection in the cytoplasm, i.e. bulk fluid motion as a result of temperature-difference-induced density gradients.
View Article and Find Full Text PDFSci Rep
July 2024
Faculty of Mathematics and Physics, Charles University, Ke Karlovu 3, 121 16, Prague, Czech Republic.
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