****NON-TECHNICAL ABSTRACT**** In a forest fire, the dividing line between burned and unburned trees is called a front. The motion of this front determines how the fire spreads through the forest. Similar front dynamics characterize the spreading of a disease in society, as well as numerous chemical processing applications, biological processes in cells and developing embryos, and plasmas in fusion reactors. The experiments supported by this grant will explore how the motion of fronts is affected by fluid mixing, e.g., forced flows in a chemical processor, winds in a forest fire, or the motion of people in society while a disease spreads. Table-top experiments using a simple chemical reaction will focus on how fronts are affected by simple flow patterns -- vortices (whirlpools) and jets. If successful, this research will help our understanding of front behavior in a wide range of systems spanning the fields of science and engineering, ultimately laying the foundation for a general theory to describe fronts in flowing systems. All of the research will be done in conjunction with undergraduate students who will participate in all aspects of the project including experimental design, construction and testing of the apparatus, data-taking and analysis, and publication and presentation of the results. These will be the first real research experiences for these students, and will play an important role in their development as scientists.
This grant will support experiments and simulations that study the effects of fluid flows on the propagation of reaction fronts. This is an issue that is applicable to a wide range of front-producing systems spanning all fields of science and engineering. The studies will examine universal features of front propagation, particularly the importance of closed and open flow structures (vortices and jet regions) on the front-propagation process. The table-top experiments funded by this grant will use variations of the Belousov-Zhabotinsky (BZ) chemical reaction, often considered to be a paradigm for front-producing and pattern forming systems. The flows will be generated with magnetohydrodynamic techniques that can produce ordered and disordered patterns of vortices and wavy jets. The goal of the research is to isolate fundamental processes in flow-reaction dynamics that could form the basis for the development of a general theory of front propagation in flowing systems. All of the research will be done in conjunction with undergraduate students who will participate in all aspects of the research including experimental design, construction and testing of the apparatus, data-taking and analysis, and publication and presentation of the results. These will be the first real research experiences for these students, and will play an important role in their development as scientists.
