-----------------------------------------------------------
Applied Mathematics Colloquium
Friday, October 10, 11:30 am
Cullimore Lecture Hall II
New
-----------------------------------------------------------
Computational Studies of the Dynamics
of Heterogeneous
Continuum Systems
Grétar Tryggvason
Department of Mechanical Engineering
Worcester Polytechnic Institute
Abstract
Systems where continuum theory provides an accurate description of the system
behavior, but where there is a large difference between the
system scale and the smallest
continuum scales are found in a wide range of industrial applications as well
as in Nature. Multiphase
flows, including bubbly flows and
boiling, sprays, and solid suspensions, are common examples. Bridging the gap
and using our
understanding of the small scales to
predict the behavior at the system scale is one of the grand challenges of
science. Direct
Numerical Simulations (DNS) of the evolution of sufficiently
small systems so that all continuum scales are fully resolved, yet large
enough so that interactions of flow
structures of different scales can take place, are increasingly playing a
central role in studies of the
dynamics of heterogeneous continuum
systems. Here, we discuss in some details recent results for wall-bounded
bubbly flows, where DNS have
yielded new and unexpected insight
into the subtle importance of accurately accounting for bubble deformability.
The development of
numerical methods for more complex multiphase flows is also underway and a few examples of simulations of boiling flows are presented.