In case of convection the code *CrysMAS* applies different solvers for equations
discretized on the unstructured and unstructured mesh. For
structured mesh an iterative SIP solver is always used. For the
unstructured mesh one of the solvers available also for solution
of temperature equation, see ** Forward** tab of
the ** Numerical Parameters** dialog. The solver
options for the unstructured mesh are described in this section.

*CrysMAS* makes simulations by repeated solution of linear
equation systems. For velocity and pressure equations, the same solvers as for forward
and inverse simulation are available, see
Forward and
Inverse.

Default solvers should not be changed, because, by experience, they produce satisfactory results. You may, however, change the parameters for pressure and velocity.

Select

**Computation**>**Convection parameters**.The

**Convection parameters**dialog opens.Click on the

**Solver**tab.The velocity solver default is the STABBiCG, the same iterative solver as for forward simulation. The pressure solver default is the direct solver GSSV, the same as for inverse simulation.

Change the default solvers and preconditioners for velocity and pressure, if necessary.

Set the convergence criteria

**Max. inner iterations**and**Desired residuum**, if desired.Click on

**Apply**and**Close**.or

Click on

**OK**to apply the changes and to close the dialog.