Sculpt Boundary Layers

Sculpt options for defining boundary layers in the mesh. Boundary layers are thin hex layers that can be defined at surfaces, extending either inward or outward from a material. The user may specify the number and thickness of the hex layers as well as the material ID of the layers. Layer thicknesses should normally be "thin" with respect to the size of the cells. Layers will not intersect, so should be defined on surfaces where nearby layers will not overlap. Boundary layers are specified based upon a material ID, where hex layers will be placed at surfaces where the material interfaces with other materials, or at free surfaces.

Boundary Layers 		--boundary_layer 	-bly
  --begin,		-beg <args>	Begin specification blayer or blayer_block
  --end,		-zzz <args>	End specification blayer or blayer_block
  --material,		-mat <args>	Boundary layer material specificaton
  --num_elem_layers,	-nel <args>	Number of element layers in blayer block
  --thickness,		-th <args>	Thickness of first element layer in block
  --bias,		-bi <args>	Bias of element thicknesses in blayer block

Sculpt Command Summary

Command: begin     Begin specification blayer or blayer_block

Long Name:     --begin 
Short Name:     -beg 
Argument Type:   blayer, blayer_block 

Defines the beginning of a specification block. Must be closed with "end" argument. Currently supports the following specifications:

blayer
Defines a boundary layer specification. Layers of hex elements are placed at the interface of a given material. Valid argumnts used within a blayer specification include: material, and begin blayer_block.

blayer_block
Defines a set of element layers within a given blayer definition that share a common material ID. Valid arguments used within a blayer_block specification include: material, num_elem_layers, thickness and bias.

Example:
The following example shows a boundary layer specification in a sculpt input file. In this example, two boundary layer blocks are defined at the interface of material 1. Two material blocks with ID 2 and 3 are generated with 2 and 1 element layers respectively.

           BEGIN BLAYER
             MATERIAL = 2
             BEGIN BLAYER_BLOCK
               MATERIAL = 3
               NUM_ELEM_LAYERS = 1
               THICKNESS = 0.1
             END BLAYER_BLOCK
             BEGIN BLAYER_BLOCK
               MATERIAL = 4
               NUM_ELEM_LAYERS = 2
               THICKNESS = 0.2
               BIAS = 1.3
             END BLAYER_BLOCK
           END BLAYER
    

Command: end     End specification blayer or blayer_block

Long Name:     --end 
Short Name:     -zzz 
Argument Type:   blayer, blayer_block 

Defines the end of a specification block. Must be preceded with "begin" argument. Currently supports arguments blayer and blayer_block.

Command: material     Boundary layer material specificaton

Long Name:     --material 
Short Name:     -mat 
Argument Type:   integer > 0 

Defines a material ID in a boundary layer specification. When used within a BLAYER specification, it references an existing material in the input where boundary layers will be generated. In most cases the material ID is defined in the diatom file and references a specific STL geometry. It can also be defined as the void material ID (VOID_MAT) or a material in a volume fraction description such as input_vfrac, input_micro, input_cart_exo or input_spn.

When used within a BLAYER_BLOCK specification, it refers to a new block that will be generated for which all elements in the blayer_block will be assigned. Normally it refers to a unique material ID that is not already referenced in the input. Where the material ID is already used, elements in the blayer block will be added to the existing material.

A material ID must be defined for both a BLAYER and BLAYER_BLOCK. This value does not have a default.

Command: num_elem_layers     Number of element layers in blayer block

Long Name:     --num_elem_layers 
Short Name:     -nel 
Argument Type:   integer > 0 

Number of element layers to be defined within a BLAYER_BLOCK specification. num_elem_layers must be defined for all BLAYER_BLOCKs.

Command: thickness     Thickness of first element layer in block

Long Name:     --thickness 
Short Name:     -th 
Argument Type:   floating point value 

Thickness of the first layer defined in a BLAYER_BLOCK. Value is an absolute distance. No deafult is provided and must be defined for all BLAYER_BLOCKs

Command: bias     Bias of element thicknesses in blayer block

Long Name:     --bias 
Short Name:     -bi 
Argument Type:   floating point value 

Bias factor applied to additional layers of a BLAYER_BLOCK. Used in conjunction with the THICKNESS parameter (thickness of first layer) it defines a multiplier for the thickness for subsequent element layers defined within the same BLAYER_BLOCK. Default BIAS is 1.0 and is optional.