7.29. Level Set

This section is referenced in the following other sections

Simulation Setup: Level Set/CDFEM

7.29.1. Level Set Interface

Scope: Aria Region
Summary: Main block for krino level set interface control mechanics.
Description: This is the main block for the level set interface control mechanics. This block specifies a level set interface that is integrated in time using an extension velocity. The plan is that the physics application code will see only this mechanics, although there may be several other supporting mechanics that are plugged in.

begin Level Set Interface InterfaceName

   Composite Name {=} Variable

   Distance Variable {=} Variable

   Initial Offset Distance {=} Offset

   Initial Scale Factor {=} Scale

   Max Feature Size On Surfaces {=} Value

   Narrow Band Element Size Multiplier {=} Value

   Narrow Band Width {=} Value

   Perform Initial Redistance {=} {false | no | off | on | true | yes}

   Redistance Method {=} {closest_point | fast_marching}

   Reinitialize Every Step

   Simple Max Feature Size On Surfaces {=} Value

   begin Analytic Initial Condition BlockName
   end

   begin Compute_Surface_Distance SurfaceName
   end

   begin Motion Specification Motion
   end

end Level Set Interface InterfaceName

7.29.1.1. Line Commands

Composite Name

Syntax: Composite Name {=} Variable
Summary: Optionally specify a composite level set name which may be used across multiple level sets to define composite phases.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Variable	string	–

Distance Variable

Syntax: Distance Variable {=} Variable
Summary: Specify the distance variable name.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Variable	string	–

Initial Offset Distance

Syntax: Initial Offset Distance {=} Offset
Summary: Specify an offset distance to be applied to the initial level set. Allows the user to grow or shrink the initialized level set.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Offset	real	–

Initial Scale Factor

Syntax: Initial Scale Factor {=} Scale
Summary: Specify an scale factor to be applied to the initial level set. Allows the user to multiple the entire level set by a constant, primarily useful for nested (concentric) level sets. This modifier gets applied after the INITIAL OFFSET DISTANCE, if there is one.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Scale	real	–

Max Feature Size On Surfaces

Syntax: Max Feature Size On Surfaces {=} Value
Summary: Specify the maximum feature size on surfaces, features smaller than this will be destroyed near all surfaces. IN BETA TESTING!

Parameter	Value	Default
{=}	{= \| are \| is}	–
Value	real	–

Narrow Band Element Size Multiplier

Syntax: Narrow Band Element Size Multiplier {=} Value
Summary: Specify the width of the narrow band width used for the level set field as the given multiplier times the maximum element length scale. If this command is omitted, the distance will be computed throughout the entire domain, but this is not generally scalable in terms of memory or cpu time.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Value	real	–

Narrow Band Width

Syntax: Narrow Band Width {=} Value
Summary: Specify the width of the narrow band. This form is deprecated. Use NARROW BAND ELEMENT SIZE MULTIPLIER instead.

Parameter	Value	Default
{=}	{= \| are \| is}	–
Value	real	–

Perform Initial Redistance

Syntax: Perform Initial Redistance {=} {false | no | off | on | true | yes}
Summary: Perform redistancing operation just after initial conditions are applied.

Parameter	Value	Default
{=}	{= \| are \| is}	–
performInitialRedistance	{false \| no \| off \| on \| true \| yes}	FALSE

Redistance Method

Syntax: Redistance Method {=} {closest_point | fast_marching}
Summary: Specify the algorithm to be used for redistancing.

Parameter	Value	Default
{=}	{= \| are \| is}	–
RedistanceMethodType	{closest_point \| fast_marching}	CLOSEST_POINT

Reinitialize Every Step

Syntax: Reinitialize Every Step
Summary: Specify that this level set interface should be re-initialized every time step. For example this can be combined with an analytic mesh surface initial condition that is moving due to applied displacements to move the CDFEM interface location with the mesh surface.

Simple Max Feature Size On Surfaces

Syntax: Simple Max Feature Size On Surfaces {=} Value
Summary: Specify the maximum feature size on surfaces, features smaller than this will be destroyed near all surfaces (simple version) IN BETA TESTING!

Parameter	Value	Default
{=}	{= \| are \| is}	–
Value	real	–