Effects of Advection on Reaction-Diffusion Waves

A quasi-one-dimensional reaction-diffusion-advection system is created by placing the classic model system for reaction-diffusion (RD) waves, the chemical Belousov-Zhabotinsky (BZ) reaction, in a syringe-capillary system. These RD waves are pure concentration profile changes of a specific chemical compound, without any mass transport in the solution. After initiating BZ waves at the open end of the capillary, BZ solution is pushed into the capillary against the direction of the wave propagation. By varying the advection velocity of the fluid ($v_\mathrm{adv}$), we observed its effect on the propagating speed of the BZ waves ($v_\mathrm{wave}$) and created, under certain conditions, quasi-one-dimensional standing waves. In this case, $v_\mathrm{adv}=v_\mathrm{wave}$ and the 'moving' wave seems to stand still within the capillary.