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6.16 Package FL.ELLSYS

This package contains the problem definition of systems of convection-diffusion-reaction equations. The system is given in the following form which is suited for a fixed-point iteration:

-div(a(x,u_old,nabla u_old) nabla u) - div(b(x,u_old,nabla u_old) u) + + c(x,u_old,nabla u_old) u = f(x,u_old, nabla u_old) - div(g(x,u_old, nabla u_old)) - div(a(x,u_old,nabla u_old) h(x,u_old, nabla u_old))

where u:G to R^N. Note that the last two terms are introduced in the variational formulation and imply a natural Neumann boundary condition derivativeun = (g+a h) cdot n at boundaries where no Dirichlet constraints are posed.

— Class: <ELLSYS-PROBLEM>

Systems of convection-diffusion-reaction equations. The coefficients should be vector-valued functions in this case.

Superclasses: <PDE-PROBLEM>

Direct slots:

— Function: ELLSYS-MODEL-PROBLEM DOMAIN NCOMPS &KEY A B C F G H DIRICHLET INITIAL EVP PROPERTIES DERIVED-CLASS

Generates a rather general elliptic problem on the given domain.

— Function: ISOTROPIC-DIFFUSION DIM VALUES

Returns a sparse diagonal diffusion tensor with isotropic diffusion in each component. value should be a vector or a number and contains the amount of diffusion in each component.

— Function: NR-OF-COMPONENTS MSFE

Returns the number of components for problem.