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Local discontinuous galerkin (LDG) method

+3 votes

Hello
I am looking for some example code that solves a heat equation or unsteady convection-diffusion equation using LDG method.
Thanks

asked Jan 28, 2014 by praveen FEniCS User (2,760 points)

1 Answer

0 votes
 
Best answer

I'm not aware of any FEniCS/DOLFIN code for LDG method. There are not any in the demos distributed with DOLFIN.

answered Jan 28, 2014 by Garth N. Wells FEniCS Expert (35,930 points)
selected Mar 27, 2014 by praveen

So let me ask my doubt in brief. Say for heat equation

$$
\frac{\partial u}{\partial t} = \frac{\partial^2 u}{\partial x^2}
$$

We write this as

$$
\frac{\partial u}{\partial t} = \frac{\partial \sigma}{\partial x}
$$

$$
\sigma = \frac{\partial u}{\partial x}
$$

When we do a DG discretization of these two equations, we get one algebraic equation. This equation can be solved on each element individually and $\sigma$ can be eliminated. Is it possible to eliminate $\sigma$ in fenics before solving for $u$ ?

You'd have to write your own assembler to eliminate $\sigma$ locally.

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