- The computational domain must be simply connected.
- Along the domain decomposition axis, physical boundary
conditions are assumed to be non-periodic.
- The current version of
`PMD` stands for 1D Domain
decomposition only which means that subdomain interfaces cannot cross.
- The interface normal vectors must be parallel to the domain decomposition
axis.
- It is up to the user to compute the interface first normal
derivatives along the domain decomposition axis.
- When using direct parallel solvers, which here are based on the
`ScaLAPACK` library, the `BLACS` process grid must be
square. This means that if Np denotes the process grid dimension,
then the size of the PMD process group must be equal to Np**2.
However this restriction doesn't stand when using parallel
iterative solvers as PCG and Bi-CGstab algorithms.
- Parallel PCG and Bi-CGstab methods, has an inconvenient property which is
the number of iterations to convergence increases as the number of
subdomains grows.