Event Type:

Applied Mathematics and Computation Seminar

Date/Time:

Friday, April 20, 2012 - 05:00

Location:

GLK 113

Guest Speaker:

Justin Finn

Institution:

OSU Department of Mechanical Engineering

Abstract:

In the last decade the notion of Lagrangian coherent structures (LCS) as

transport barriers in unsteady fluid flows has evolved from dynamical

systems theory, and has proven its utility in understanding a number of

mixing and transport problems. Typically, computation of the LCS involves

post processing of experimentally or numerically obtained fluid velocity

fields to obtain a sequence of flow maps (vector fields which describe

displacement patterns over a finite time interval), and can be prohibitively

expensive for large-scale complex flows of engineering interest. In this

talk I will discuss an alternative approach, which is to compute the LCS on

the fly during direct numerical simulation (DNS) of the 3D Navier-Stokes

equations. This changes the problem size restriction for LCS analysis from

``how much time do you have?'' to ``how big of a problem can you

simulate?''. Illustrative examples will be presented to demonstrate the

capability, advantages, and challenges of the proposed approach.