7.1. Adaptivity Settings

This section is referenced in the following other sections

7.1.1. Adaptivity Options

Scope: Sierra
Summary: Used to define markers and indicators used for adaptivity

begin Adaptivity Options AdaptBlockName

   begin Function Marker MarkerName
   end

   begin Uniform Marker MarkerName
   end

   begin Field Indicator IndicatorName
   end

   begin Gradient Error Indicator IndicatorName
   end

   begin Signed Distance Indicator IndicatorName
   end

end Adaptivity Options AdaptBlockName

7.1.2. Adaptiveloop

Scope: Sequential, Solution Control Description, System, Transient
Summary: Specify block-style post processing command

begin Adaptiveloop Name

   Advance Name... [ When When-expression  ]

   Adapt Mesh For AdaptRegionName Using AdaptBlockName [When WhenExpression]

   Event Name... [ When When-expression  ]

   Postprocess Aria Region RegionName [Equation System EquationSystemName  | When WhenExpression]

   Transfer Name [ When When-expression  ]

   begin Sequential Name
   end

   begin Transient Name
   end

end Adaptiveloop Name

7.1.2.1. Line Commands

Advance

Syntax: Advance Name… [ When When-expression ]
Summary: Used within a Solver Control block to indicate a single step that advances the solution. The name is that matches the physics.

Parameter	Value	Default
Name	string…	–

Adapt Mesh

Syntax: Adapt Mesh For AdaptRegionName Using AdaptBlockName [When WhenExpression]
Summary: Adapt the mesh using the adaptive command block name

Parameter	Value	Default
AdaptRegionName	string	–
AdaptBlockName	string	–
WhenExpression	(expression)	–

Event

Syntax: Event Name… [ When When-expression ]
Summary: Used within a Solver Control block to indicate a single step that has no time associated with it. It can cause a solution transfer between regions or cause something to print.

Parameter	Value	Default
Name	string…	–

Postprocess Aria Region

Syntax: Postprocess Aria Region RegionName [Equation System EquationSystemName | When WhenExpression]
Summary: Run Aria Region postprocessors. If specified, only the single equation system’s PPs are run.

Parameter	Value	Default
RegionName	string	–
EquationSystemName	string	–
WhenExpression	(expression)	–

Transfer

Syntax: Transfer Name [ When When-expression ]
Summary: A Solver Control Transfer line command which executes all transfers defined from the specified region. All transfers with a send region of ‘name’ will be executed.

Parameter	Value	Default
Name	string	–

7.1.3. Field Indicator

Scope: Adaptivity Options
Summary: An indicator calculated from a nodal field
Description: This calculates an element field with the element centroid value defined by the specified nodal field. Global variables for the min, max, and average of the field are also calculated.

begin Field Indicator IndicatorName

   Location = Value...

   Nodal Field = Value

   Reduction = {centroid | max | min}

end Field Indicator IndicatorName

7.1.3.1. Line Commands

Location

Syntax: Location = Value…
Summary: A block or list of blocks defining the location of indicator

Parameter	Value	Default
Value	string…	–

Nodal Field

Syntax: Nodal Field = Value
Summary: Nodal field name to do the element centroid projection on

Parameter	Value	Default
Value	string	–

Reduction

Syntax: Reduction = {centroid | max | min}
Summary: Project nodal field onto element centroid, max of nodes on element, or min of nodes on element. DEFAULT = CENTROID

Parameter	Value	Default
reduction_enumeration	{centroid \| max \| min}	–

7.1.4. Signed Distance Indicator

Scope: Adaptivity Options
Summary: An indicator based on distance from a nodal signed distance field
Description: This calculates the distance from an element to an interface defined by a nodal signed distance field. If the element spans the interface its distance is 0. For other elements, its distance is the minimum distance of any of its nodes

begin Signed Distance Indicator IndicatorName

   Location = Value...

   Signed Distance Field = Value

end Signed Distance Indicator IndicatorName

7.1.4.1. Line Commands

Location

Syntax: Location = Value…
Summary: A block or list of blocks defining the location of indicator

Parameter	Value	Default
Value	string…	–

Signed Distance Field

Syntax: Signed Distance Field = Value
Summary: Nodal distance field name to calculate distance from

Parameter	Value	Default
Value	string	–

7.1.5. Gradient Error Indicator

Scope

Adaptivity Options

Summary

An indicator based on nonlinearity in the gradient of a nodal field

Description

This calculates a gradient-based error indicator using the difference between the element-based gradient and a projected nodal gradient. The error indicator on a given element is the average of the error at each of its nodes, normalized by an element length scale.

The element gradient is the average of the gradient at each integration point:

$\nabla \phi_e = \frac{1}{n_{ip}} \sum_{ip=1}^{n_{ip}}{ \nabla \phi_ip }$

Then the nodal gradient is assembled as a volume-weighted average of the gradient of the connected elements

$\nabla \phi_n = \frac{\sum_{i=1}^{n_{elems}}{\nabla \phi_{e,i} V_{e,i}}}{\sum_{i=1}^{n_{elems}}{V_{e,i}}}$

Finally, the gradient error per element is calculated as the average difference between the element gradient and its nodal gradients, scaled by a characteristic element length scale

$E_g = \frac{V_e^{1/n_{dim}}}{n_{nodes}} \sum_{i=1}^{n_{nodes}}{||\nabla \phi_{n,i} - \nabla \phi_e||}$

Global variables for the min, max, and average of the final indicator error field are also calculated.

begin Gradient Error Indicator IndicatorName

   Location = Value...

   Nodal Field = Value

end Gradient Error Indicator IndicatorName

7.1.5.1. Line Commands

Location

Syntax: Location = Value…
Summary: A block or list of blocks defining the location of indicator

Parameter	Value	Default
Value	string…	–

Nodal Field

Syntax: Nodal Field = Value
Summary: Nodal field name to compute the gradient based error indicator

Parameter	Value	Default
Value	string	–

7.1.6. Uniform Marker

Scope: Adaptivity Options
Summary: Uniformly mark all blocks for refinement
Description: This will mark all elements in the specified block(s) for refinement until they reach their max refinement levels.

begin Uniform Marker MarkerName

   Location = Value...

   Maximum Refinement Level = MaxRefineLevel

end Uniform Marker MarkerName

7.1.6.1. Line Commands

Location

Syntax: Location = Value…
Summary: List block(s) or sideset(s) where marker should be applied. When a sideset marker is applied, its attached element is marked.

Parameter	Value	Default
Value	string…	–

Maximum Refinement Level

Syntax: Maximum Refinement Level = MaxRefineLevel
Summary: Set maximum refinement level for this marker

Parameter	Value	Default
MaxRefineLevel	integer	–

7.1.7. Function Marker

Scope: Adaptivity Options
Summary: Use string functions to define refinement and unrefinement rules
Description: This takes a user-defined string function for refinement and/or un-refinement. The function can include time (t), time step (dt), position (x, y, z), any global variable, or any element field. If both refinement and un-refinement rules are specified, the refinement rule will take precedence.

begin Function Marker MarkerName

   Location = Value...

   Maximum Refinement Level = MaxRefineLevel

   Refine When refinefunc

   Unrefine When unrefinefunc

end Function Marker MarkerName

7.1.7.1. Line Commands

Location

Syntax: Location = Value…
Summary: List block(s) or sideset(s) where marker should be applied. When a sideset marker is applied, its attached element is marked.

Parameter	Value	Default
Value	string…	–

Maximum Refinement Level

Syntax: Maximum Refinement Level = MaxRefineLevel
Summary: Set maximum refinement level for this marker

Parameter	Value	Default
MaxRefineLevel	integer	–

Refine

Syntax: Refine When refinefunc
Summary: String function condition for refinement based on indicators

Parameter	Value	Default
refinefunc	“string”	–

Unrefine

Syntax: Unrefine When unrefinefunc
Summary: String function condition for un-refinement based on indicators

Parameter	Value	Default
unrefinefunc	“string”	–