Kumar M. Bobba
Graduate Aeronautical Laboratories, 205-45
California Institute of Technology
Pasadena, CA 91125, USA
bobba@its.caltech.edu
Abstract:
Understanding transition from laminar flow to turbulence flow is a longstanding
challenge in fluid mechanics. A
unifying framework to study transition will be presented. We will argue that
there is a fundamental difference in transition scenarios between channel flows
and more generic flows like Rayleigh-Benard flows etc. We will also show how
developing a mathematical framework to understand uncertainties is the key to
transition and that there are some very fundamental limitations on what can be
achieved. As a first cut various performance measures will be introduced and
will be shown how they peak at 70-100 wall units as seen in channel flow
experiments. Evidence will be presented to show that surprising low order
models exist for boundary layer processes. The ideas will be illustrated by
computations done on Couette flow.