ELFT HÍRADÓ

[ilka AT konkoly.hu (Kalman Belane)]

                            Meghivo

      az MTA Konkoly Thege Miklos Csillagaszati Kutatointezete
                         szeminariumara

Eloado: Barna L. Bihari                                                       
                         
        Center for Applied Scientific Computing
        Lawrence Livermore National Laboratory

Cim: "High Order Numerical Methods for Unsteady Hydrodynamical 
Simulations"
                                                                              
  
                                                                              
  
Weak solutions of nonlinear hyperbolic conservation laws can 
have discontinuities such as shocks and contact discontinuities as
mathematically admissible ingredients.  Conservative schemes can  
actually compute the correct weak solutions as the spatial resolution
h tends to zero, but depending on the order of accuracy, may smear
shocks and the long-time solution can have large dispersive and  
dissipative errors. High order schemes, on the other hand, can
dramatically reduce these errors, but are notorious for producing
oscillations of size O(1) near discontinuities, despite their formal
Weighted ENO (WENO) schemes remedy this by choosing the spatial stencil
or at the very least reducing the size of oscillations to O(h^r), r
and their predecessor, the TVD scheme, we demonstrate the scheme on some 
1-D test problems.                                 
Next, we show the utility of the ENO/WENO idea when it is applied to
multidimensional hydrodynamics.  We show some typical problems for
order methods.  Because of the need to compute multiple stencils, WENO
However, for unsteady compressible flows, it yields a high quality
produces this same quality at only a fraction of the cost.  The hybrid
adaptive stencil mechanism only near irregularities in the solution
such as shocks, contacts, reaction fronts, etc.  The rest of the domain
with the original WENO scheme show that the new method produces
solutions which are virtually the same as their pure WENO counterparts,
but run at about 2 to 6 times faster in 2-D.

A szeminárium idõpontja: 2003. julius 07, hetfo. 14 ora

Helyszine: MTA Konkoly Thege Miklós Csillagászati Kutatóintézete
           1121 Budapest Konkoly Thege M. ut 13-17.  


                                      Patkós László s.k.