Complex Systems

On Lagrangian Aspects of Flow Simulation Download PDF

Hassan Aref
Scott W. Jones
Department of Applied Mechanics and Engineering Science,
University of California-San Diego, LaJolla, CA 92093, USA

Grétar Tryggvason
Department of Mechanical Engineering and Applied Mechanics,
University of Michigan, Ann Arbor, MI 48109, USA


Many numerical methods for fluid flow simulation use representations of the flow in terms of Lagrangian elements as opposed to Eulerian fields. Such methods have considerable advantages when they can be adapted to the physical situation in question. We show examples of this for the case of generalized vortex methods applied to stratified flows with sharp interfaces. We also discuss the notion of chaotic advection, i.e., the feature that Lagrangian elements can have chaotic motion even in Eulerian flow fields that are entirely regular. We discuss the relation of "lattice gas" methods to these issues.