Magnetic resonance studies of transport and reaction in vortical flow

[摘要] This thesis explores the coupling of autocatalytic reactions, such as the oscillating Belousov- Zhabotinsky reaction, with vortical flows produced in a Couette cell. Similarly to many Reaction-Diffusion-Advection (RDA) systems found in nature, the resulting systems are characterised by chemical cycles maintained out of equilibrium by transport processes involving complex flow properties, such as periodicity and vorticity. In this project, an integrated approach was developed, combining optical and magnetic resonance techniques with modelling, to study transport and reaction in vortical flows. Flow structure and molecular displacements within stationary and translating vortices were investigated using a combination of magnetic resonance (MR) velocity and diffusion mapping with MR propagator experiments. A model based on MR experimental data was developed to simulate molecular displacements and provide quantitative information on micro-mixing and long time-scale axial dispersion. Simulations of molecular displacements allow linkage of molecular transport with the propagation of chemical waves travelling through vortical flows. The macroscopic patterns arising from these RDA systems, in combination with modelling results, allowed understanding coupling mechanisms between flow and chemistry and characterising inter- and intra- vortex mixing. Finally, MR imaging of chemical waves was shown to compare well with molecular displacement simulations, providing with a means for characterising the interplay of flow and chemistry in reactive flow systems.

[发布机构] University:University of Birmingham;Department:School of Chemistry

[关键词] Q Science;QD Chemistry