Research
Overview
Descriptions of fluid flow fall into two categories. We can, for instance, take the Eulerian approach and specify how the flow field evolves in time at a (potentially very large) set of fixed locations in space. Alternatively, we can describe the time evolution of the flow by considering the trajectories of infitesimal fluid elements. This type of description is known as the Lagrangian approach. Eulerian measurements have been made for a very long time; large-scale Lagrangian measurements, however, are a much more recent innovation.
While both of these descriptions contain the same fundamental information, fluid mechanics problems often appear simpler in one framework or the other. The Lagrangian approach, for instance, is the natural one for studying problems of mixing and transport. Since translating between Eulerian and Lagrangian statistics remains an unsolved problem, we need highly resolved Lagrangian measurements in order to address a wide range of real, human-scale problems, including pollution transport in the atmosphere, mixing in industrial processes, and the dynamics of droplet formation in clouds.
In the Ouellette lab, we specialize in Lagrangian measurements using high-speed, high-resolution particle tracking techniques. Follow the links to the left for details of specific projects.
We are also associated with the International Collaboration for Turbulence Research (ICTR), a multinational group of scientists dedicated to sharing their theoretical, numerical, and experimental expertise in order to further our understanding of the Lagrangian nature of turbulence.