OpenFOAM 2.2.0: Boundary Conditions

Jump Boundary Conditions

A new jump condition framework has been implemented that allows jump conditions to be applied to any field variable across matching cyclic and non-matching cyclicAMI patches. The jump can be specified as either

• fixedJump, fixedJumpAMI: a spatially varying jump field, fixed in time, or
• uniformJump, uniformJumpAMI: a uniform jump value in space that can vary with time

The first boundary patch (according to the boundary list in the constant/polyMesh/boundary file) is assigned as the master patch on which the jump condition is specified.

The jump condition patch geometry can be created manually; however, it is generally more practical to use the updated createBaffles utility. When specifying the field boundary conditions, a fixedJump condition is prescribed by:

side1
{
    type            fixedJump;
    patchType       cyclic;
    jump            uniform 1;
    value           $internalField;
}
side2
{
    type            fixedJump;
    patchType       cyclic;
    value           $internalField;
}

Note that the patchType entry must specify the underlying cyclic patch type. The jump entry is specified as a field, set to a uniform value of 1 in the above on the master patch, side1, only. A time-varying uniformJump condition can be set using:

side1
{
    type            uniformJump;
    patchType       cyclic;
    jump            constant 1;
    value           $internalField;
}
side2
{
    type            uniformJump;
    patchType       cyclic;
    value           $internalField;
} 

Here, the jump is a DataEntry type, allowing the jump to be described as a function of time, e.g. constant value, polynomial, table etc.

To use the AMI variants, the type and patchType entries should be set to fixedJumpAMI (or uniformJumpAMI) and cyclicAMI, respectively.