Description
The control functions control the distribution of grid points during iterative solution of the elliptic PDE. These control functions are calculated and updated automatically between elliptic PDE iterations and are formed as a blended combination of two independent function sets known as interior and boundary control functions.
The Interior Control Functions influence the distribution of interior grid points. Use the Interior pull down list to select the function to be used:
Laplace, Thomas-Middlecoff, or Fixed Grid.
Interior control functions are used to influence the distribution of grid points on the interior of the grid. Three different interior control functions, described below, are available in Fidelity Pointwise:
- Laplace: This interior control function provides a very smooth distribution of grid points in the grid interior, but it does not provide any degree of orthogonality or clustering.
- Thomas-Middlecoff: (Ref. 36) This interior control function will cluster grid points on the grid's interior based on how the grid points are clustered on the boundaries. This method is very reliable and stable for a wide range of applications and is, therefore, Fidelity Pointwise's default interior control function.
- Fixed Grid: This interior control function is used to eliminate grid line slope discontinuities from the grid's interior while preserving the rest of the grid. Its effects are very subtle. The final grid will exhibit the same general features as the starting grid, including regions of clustering and orthogonality, but any slope discontinuities will be smoothed. This method should not be used unless the starting grid is of adequate quality except for the discontinuities.