OpenFOAM guide/SurfaceInterpolation;;deltaCoeffs

From OpenFOAMWiki

surfaceInterpolation::deltaCoeffs

Reciprocal of cell-to-cell (centres) distance, with orthogonality correction.

On an orthogonal grid: C_\delta = \frac{1}{\delta}

Where:

  • \delta is the cell-to-cell distance.

Standard definition: C_\delta = \frac
{\mathbf{\hat{n}} \bullet \boldsymbol \delta}
{\left \vert \boldsymbol \delta \right \vert^2}

Where:

  • \mathbf{\hat{n}} is the surface normal vector; and
  • \boldsymbol \delta is the cell-to-cell vector.

Used in OpenFOAM for stability with poor meshes: C_\delta = \frac{1}
{\text{max}\left (
	\delta \bullet \mathbf{\hat{n}},
	0.05 \left \vert \delta \right \vert
\right )}