We propose a simple numerical method for capturing the steady state solution of hyperbolic systems with geometrical source terms. We use the interface value, rather than the cell-averages, for the source terms that balance the nonlinear convection at the cell interface, allowing the numerical capturing of the steady state with a formal high order accuracy. This method applies to Godunov or Roe type upwind methods but requires no modification of the Riemann solver. Numerical experiments on scalar...
We propose a simple numerical method for capturing the
steady state solution of hyperbolic systems with geometrical
source terms. We use
the interface value, rather than the cell-averages,
for the source terms that balance the nonlinear convection
at the cell interface, allowing the numerical capturing of the steady
state with a formal high order accuracy. This method applies to Godunov
or Roe type upwind methods but
requires no modification of the Riemann solver.
Numerical experiments on scalar...
The phenomenon of roll waves occurs in a uniform open-channel flow down an incline, when the Froude number is above two. The goal of this paper is to analyze the behavior of numerical approximations to a model roll wave equation which arises as a weakly nonlinear approximation of the shallow water equations. The main difficulty associated with the numerical approximation of this problem is its linear instability. Numerical round-off error can easily overtake the numerical solution and yields false...
Numerically solving the Boltzmann kinetic equations with the small Knudsen number is challenging due to the stiff nonlinear collision terms. A class of asymptotic-preserving schemes was introduced in [F. Filbet and S. Jin,J. Comput. Phys. 229 (2010) 7625–7648] to handle this kind of problems. The idea is to penalize the stiff collision term by a BGK type operator. This method, however, encounters its own difficulty when applied to the quantum Boltzmann equation. To define the quantum Maxwellian...
Numerically solving the Boltzmann kinetic equations with the small Knudsen number is
challenging due to the stiff nonlinear collision terms. A class of asymptotic-preserving
schemes was introduced in [F. Filbet and S. Jin,J. Comput. Phys. (2010)
7625–7648] to handle this kind of problems. The idea is to penalize the stiff collision
term by a BGK type operator. This method, however, encounters its own difficulty when
applied to the quantum Boltzmann...
The phenomenon of roll waves occurs in a uniform open-channel
flow down an incline, when the Froude number is above two.
The goal of this paper is to analyze the behavior of numerical
approximations to a model roll wave equation ,
which arises as a weakly nonlinear approximation of the shallow water
equations. The main difficulty associated with the numerical approximation of
this problem is its linear instability. Numerical round-off error
can easily overtake the numerical solution and yields...
We present a domain decomposition theory on an interface problem for the linear transport equation between a diffusive and a non-diffusive region. To leading order, i.e. up to an error of the order of the mean free path in the diffusive region, the solution in the non-diffusive region is independent of the density in the diffusive region. However, the diffusive and the non-diffusive regions are coupled at the interface at the next order of approximation. In particular, our algorithm avoids iterating...
We present a domain decomposition theory on an interface problem
for the linear transport equation between a diffusive and a non-diffusive region.
To leading order, up to an error of the order of the mean free path in the
diffusive region, the solution in the non-diffusive region is independent of the
density in the diffusive region. However, the diffusive and the non-diffusive regions
are coupled at the interface at the next order of approximation. In particular, our
algorithm avoids iterating...
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