An implementation of the H operator, an off-diagonal function used in linearizing the convection term. The momentum equation can be expressed as:
- The subscript p is the cell volume index;
- A are discretization coefficients;
- U is velocity;
- p is pressure; and
- H is given by:
By face index:
- A are matrix coefficients;
- o and n are the owner and neighbour indices;
- i is the face index;
- is the fvMatrix field variable (usually velocity, 'U);
- S is the discretization source term.
By cell volume index:
- r are related cells.
The calculation of the sum of related cells is performed by lduMatrix;;H.
- What I'm calling related cells is conventionally called neighbours. But OpenFOAM has a different meaning for neighbours, so the term related cells is used.