Proximity Size Function

The proximity size function is the minimum number of element layers created in regions that constitute "gaps" in the model. For the purposes of specifying a proximity size function, a gap is defined in one of two ways:

The internal volumetric region between two faces
The area between two opposing boundary edges of a face

The following properties define the proximity size function.


Minimum size	The global minimum size to be used in proximity size function calculations. Some element sizes may be smaller than this based on local feature sizes or other geometric anomalies. You can accept the predefined setting or specify a value greater than 0.
Maximum face size	The maximum size to be used for surface meshing. Element faces may be larger than this size based on hard edge sizes or floating point arithmetic. Specify a value greater than 0 or accept the predefined setting.
Maximum size	The maximum size to be used in proximity size function mesh calculations. Specify a value greater than 0 or accept the predefined setting.
Growth rate	Represents the increase in element edge length with each successive layer of elements. For example, a growth rate of 1.2 results in a 20% increase in element edge length with each succeeding layer of elements. Specify a value from 1.0 to 5.0 or accept the predefined setting. The predefined setting is 1.2.
Proximity size function sources	Determines whether regions of proximity between faces and/or edges are considered when proximity size function calculations are performed. Choose one of the following: Edges: Considers edge-edge proximity. Face-face and face-edge proximity are not considered. Faces: This is the predefined setting. Considers face-face proximity between faces. Face-edge and edge-edge proximity are not considered (that is, the trailing edge of fluid around wings will not be captured with this setting). Faces and edges: Considers face-face and edge-edge proximity. Face-edge proximity is not considered.
Number of cells across gap	The minimum number of layers of elements to be generated in the gaps. You can specify a value from 1 to 100 or accept the predefined setting. The predefined setting is 1. The value of Number of cells across gap is an approximation: The value may not be satisfied exactly in every gap. When sweeping, interval assignment may change the number of divisions (that is, elements or cells) in a gap. You must define a minimum size such that it allows the specified Number of cells across gap to be achieved. For example, if you have a gap of 1 mm, the minimum size is 0.5 mm, and the value of Number of cells across gap is 3, only 2 cells can be generated in the gap. Faces and edges: Considers face-face and edge-edge proximity. Face-edge proximity is not considered.
Maximum boundary layers	Boundary layers improve the mesh to resolve high gradients of velocity or temperature near the wall for fluid flow simulations. For fluid flow and fluid-solid heat transfer simulations, the default maximum boundary layers are 3. You can modify the number of boundary layers, increasing the number of layers improves accuracy and increases the solution time.