报告人：Julian Koellermeier（Freie Universität Berlin）
时间：2018-10-23 14:00-15:00
地点：Room 1493, Sciences Building No. 1
Abstract: The Boltzmann equation can be used for numerical simulations of rarefied gases using
continuum models. Examples of continuum models beyond the validity of Euler or Navier-Stokes
equations are so-called moment models that extend the number of flow variables by additional
moments to account for non-equilibriumeffects. An accurate solution of the Boltzmann equation
by moment models requires a large number of those moments.
In this talk, I will give a brief introduction to moment models for the Boltzmann equation and then
present a filtered hyperbolic moment method that uses a filter for the higher order moment coefficients.
It can be shown that filtering is equivalent to an additional source term in the moment model. The
application of the filter leads to accelerated convergence of the moment model. I will show the
analogy to averaged solutions and motivate the use of filters and additional source terms along with
numerical results. The new method outperforms existing methods with respect to accuracy without
additional computational cost.
