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SCD/CSS SEMINAR:
Revisiting turbulence at large Reynolds
numbers
Speaker and Affiliation:
Pablo Mininni ~ IMAGe/TNT
Abstract:
Several of the numerical investigations of turbulent flows are done in
a rather abstract framework: that of three-dimensional rectangular
periodic boundary conditions. This has happened for several reasons, an
important one of which is that one of the best existing numerical techniques
for investigating turbulence has been the Orszag-Patterson pseudospectral
method that relies heavily on the fast Fourier transform. The method is
non-dissipative, non-dispersive, and high-order. These are essential features
for the study of turbulent flows. Another reason is that the results of such
computations appear in a form that compares easily with homogeneous and
isotropic turbulence theory predictions in the Kolmogorov theory. Several
techniques have been developed to parallelize efficiently this method on
distributed memory computers. In this talk we will discuss the methods and
results from high-resolution simulations of hydrodynamic (HD) and magneto
hydrodynamic (MHD) turbulence with Taylor Reynolds numbers up to 1200, done at
NCAR and PSC. A pseudo spectral code that scales up to thousands of processors
was used. We have re-investigated some familiar turbulence problems with the
intent of revising some of the prevailing assumptions about the locality of
interactions between spatial scales in Kolmogorov theory.
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Date, Time, and
Location:
NCAR