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Time : July 14,
10:00--12:00
Venue: 海韵校区实验楼 105
Schedule:
10:00, Professor Shuchuan Dong, Purdue
University
Exploring the Secret of Turbulence with Numerical
Simulations: Issues,
Challenges and Algorithms
Abstract:
The turbulent motion of fluids has captured the fancy of observers
of nature for most of recorded history. from howling winds to
swollen floodwaters and from falling leaves to the swirls of
steaming coffee, turbulence constantly competes for our attention
and has constantly challenged the human quest for authority over
the world around us.
Since the first computation by Orszag & Patterson with a
Fourier spectral method nearly four decades ago, numerical
simulation has become a primary, and arguably the most powerful,
tool in the scientific arsenal to tackle the turbulence problem.
Turbulence simulation at high Reynolds numbers in complex flow
geometries is the envy of computational fluid dynamics. But
achieving it demands significant advancements of the fundamental
computational techniques to overcome serious challenges. In this
talk we will focus on three of the challenges -- time step size
constraint, algorithmic scalability, and parallel scalability --
and outline approaches that can potentially overcome these
challenges.
11:00, Professor Min Chen, Purdue University
Boussinesq systems for water waves
Abstract:
In this talk, I will present joint works over the years on the
existence and stabilities of special solutions, which include
solitary wave solutions, cnoidal wave solutions, standing wave
solutions and two-dimensional wave patterns, for a
class of Boussinesq systems. The techniques used in the
existence results include, but not limited to, perturbation theory
and topological index theory. Numerical simulations designed to
gain more on tsunami and wave patterns will be carried out
and compared with theoretically results and fields
data.
11:30, Professor Li-Lian Wang, Nanyang Technological
University of Singapore
Fast high-order methods for time-domain wave scattering
with exact nonreflecting boundary condition
Abstract:
In this talk, I shall present a fast spectral-Galerkin method and
Newmark's time integration for time-dependent wave scattering with
exact Dirichlet-to-Neumann non-regflecting boundary condition
(DtN-NRNB). Our emphasis will be put on the efficient treatment for
the NRNB, which is global in space and time and has been a
longstanding obstacle for time-domain computations.