Reactions in Non-Uniform Flows

Mixing-driven reactions are ubiquitous in natural environments and incomplete mixing has long plagued our ability to accurately predict them. Additionally, flows in natural environments are non-uniform, often with large degrees of shear. This can lead to stretching of plumes that strongly influences mixing and thus reactive processes. In this talk we apply a novel particle tracking method to study the model reaction A + B → 0 occurring in a background shear flow. Shear acts in such a way to enhance mixing, but a pertinent question is by how much? In particular we explore how this system behaves relative to the case with no flow, which has received much attention in recent years. A thorough understanding of shear flow is useful since it can be seen as a local approximation to any smooth flow. Finally, we discuss a theoretical framework that aims to capture incomplete mixing effects using the mathematical principle of subordination.