Effects of gravity modulation on the dynamics of a radial A + B → C reaction front

The dynamics of radial A + B → C reaction fronts can be affected by buoyancy-driven convection. Motivated by recent advances in reaction-diffusion-advection (RDA) systems theory, we investigated experimentally a radial A + B → C RDA system under modulated gravity, using a Hele-Shaw cell setup onboard a parabolic flight. We evaluated characteristic properties of the RDA models, such as the temporal evolution of the total amount of product C, the width and position of the reaction front and compared them with theoretical predictions. During increased gravity, we observed an increase in the total amount of product C, formed and the front width, compared to the corresponding normal-gravity experiments, caused by the stronger buoyancy-driven convection in the former case. Finally, we report on experiments performed entirely in absence of gravity, eliminating buoyancy-driven convection. Despite the short observation time, comparison with ground experiments showed the effect of buoyant convection on radial RDA fronts, enhancing mixing and increasing product generation.