GfsDiffusion
From Gerris
GfsDiffusion defines a diffusion or viscosity coefficient as well as optional parameters for the diffusion solver.
The syntax in parameter files is:
[ GfsFunction ] { tolerance = 1e-6 nrelax = 4 erelax = 1 minlevel = 0 nitermax = 100 nitermin = 1 beta = 0.5 }
where the GfsFunction is the value of the diffusion coefficient and the parameter block is optional. The parameters are:
- tolerance
- the maximum residual allowed for the iterative solution of the diffusion equation.
- nrelax
- the number of relaxations per level.
- erelax
- the factor by which to multiply the number of relaxations when decreasing the level by one.
- minlevel
- the minimum level to consider.
- nitermax
- the maximum number of iterations.
- nitermin
- the minimum number of iterations.
- beta
- the "implicitness" parameter. 1/2 for Crank-Nicholson and 1 for backward Euler.
The default parameters are those given in the syntax description.

