Boundary Conditions

1.        Review the position of all domain boundaries to ensure that well-posed boundary conditions can be prescribed.

2.        Define the type of boundary condition to be applied.

• Dirichlet or Neumann. - Steady or unsteady.
• Select boundary types for all free and solid boundaries.
• Note that software-default boundary conditions may not be appropriate.
• Ensure consistency, especially for high-speed flow.

3.        Prescribe steady-state or time-varying boundary values or fluxes as required at all boundaries.  Give additional consideration to defining heat and mass transfer boundaries to ensure that these adequately describe the problem.  Check that software default values, e.g. turbulence parameters, are appropriate.

4.        Undertake sensitivity tests, where necessary, to address uncertainty in boundary conditions.

• To the location of domain boundaries.
• To the type of boundary condition applied.
• To prescribed boundary values or fluxes.