# Category 16: Shell Equations#

These boundary conditions are applied to shell equations, a special category of equations applied on 1D boundaries of 2D surfaces in Goma.

## SHELL_SURFACE_CHARGE#

BC = SHELL_SURFACE_CHARGE SS <bc_id> <integer>


### Description / Usage#

(WIC/POTENTIAL)

This boundary condition card is used to add to the potential equation the surface charge term at a shell surface. Definitions of the input parameters are as follows:

 SHELL_SURFACE_CHARGE Name of the boundary condition (). SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (side set in EXODUS II) in the problem domain. This boundary must coincide with the shell element block on which the surface charge equation is applied. Integer value indicating the bulk element block ID from which to apply the boundary condition (not currently implemented).

This boundary condition is currently inoperative.

### Examples#

For a system consisting of a solid material (element block ID 1) with a conducting shell surface (element block ID 2) whose location coincides with side set 20, the following is a sample usage:

BC = SHELL_SURFACE_CHARGE SS 20 1


### Technical Discussion#

This boundary condition was originally developed to allow for fluid slip near a dynamic contact line, a necessary condition for dynamic wetting line motion when the contact angle is not 180 degrees (viz. rolling motion condition). The slippage mechanism was deployed through the use of Navier’s slip condition, which basically goes as

where E is the electric field vector, the superscripts (o) and (i) denote the outer and inner phases, n is a unit normal pointing into the outer phase, $$\varepsilon$$ is the electrical permittivity, E = –$$\Delta$$ V is the electric field and V is the voltage or electric potential.

## SHELL_SURFACE_CHARGE_SIC#

BC = SHELL_SURFACE_CHARGE_SIC SS <bc_id> <integer>


### Description / Usage#

(WIC/POTENTIAL)

This boundary condition card is used to add to the potential equation the surface charge term at a shell surface. Physically it is the same as the SHELL_SURFACE_CHARGE boundary condition, but is applied as a strongly-integrated condition. Definitions of the input parameters are as follows:

 SHELL_SURFACE_CHARGE_SIC Name of the boundary condition (). SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (side set in EXODUS II) in the problem domain. This boundary must coincide with the shell element block on which the surface charge equation is applied. Integer value indicating the bulk element block ID from which to apply the boundary condition (not currently implemented).

This boundary condition is currently inoperative…

### Examples#

For a system consisting of a solid material (element block ID 1) with a conducting shell surface (element block ID 2) whose location coincides with side set 20, the following is a sample usage:

BC = SHELL_SURFACE_CHARGE_SIC SS 20 1


### Technical Discussion#

This boundary condition applies a surface charge balance along the shell

surface.. In its most general form, this balance is written

where E is the electric field vector, the superscripts (o) and (i) denote the outer and inner phases, n is a unit normal pointing into the outer phase, $$\varepsilon$$ is the electrical permittivity, $$\underline{E}$$ = –$$\Delta$$ V is the electric field and V is the voltage or electric potential.

## SURFACE_ELECTRIC_FIELD#

BC = SURFACE_ELECTRIC_FIELD SS <bc_id> <integer> <integer> <integer>


### Description / Usage#

(WSG/SURFACE CHARGE)

This boundary condition card is used to apply a part of the shell surface charge equation which includes the electric field, the negative gradient of the potential variable which is applied on a neighboring bulk block. It is actually an integral part of the surface charge equation. Definitions of the input parameters are as follows:

 SURFACE_ELECTRIC_FIELD Name of the boundary condition (). SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (side set in EXODUS II) in the problem domain. This boundary must coincide with the shell element block on which the surface charge equation is applied. Bulk element block ID (from ExodusII database) for neighboring bulk element block on which the potential equation is applied. Shell element block ID (from ExodusII database) for shell block on which the surface charge equation is applied.

This boundary condition is currently inoperative…

### Examples#

For a system consisting of a solid material (element block ID 1) with a conducting shell surface (element block ID 2) whose location coincides with side set 20, the following is a sample usage:

BC = SURFACE_ELECTRIC_FIELD SS 20 1 2


### Technical Discussion#

This is a special type of boundary condition, WEAK_SHELL_GRAD, which is a portion of a shell equation which involves spatial gradients of bulk variables. Since the values of bulk variable gradients depend on all of the degrees of freedom of that variable in the bulk element, and sensitivities to the off-shell degrees of freedom must be applied, a portion of the equation must be evaluated from the bulk side. This is done in Goma by means of a WEAK_SHELL_GRAD boundary condition which evaluates these terms and all bulk sensitivities from the bulk side, the saves these values for later recall when the rest of the surface charge equation is assembled.

In this case, the term n • $$\Delta$$ V and its potential sensitivities are evaluated within the bulk element for inclusion in the surface charge balance along the shell surface.. I

No References.

## SH_TENS#

BC = SH_TENS NS <bc_id> <float1> [float2]


### Description / Usage#

(DC/shell_tension)

This Dirichlet boundary condition specification is used to set a tension (in stress per unit length) to the inextensible shell equations (see EQ = shell_tension and EQ = shell_curvature) at an endpoint. This boundary condition can be applied in two dimensions only, and only to the endpoint of a bar-type element. In put is as follows :

 SH_TENS Boundary condition name () that defines the shell tension (compressive or expansion depending on the sign). NS Type of boundary condition (), where NS denotes node set in the EXODUS II database. Note that this must be a single-node node set representing and endpoint to a bar element type. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. Value of tension. [float2] An optional parameter (that serves as a flag to the code for a Dirichlet boundary condition). If a value is present, and is not -1.0, the condition is applied as a residual equation. Otherwise, it is a “hard set” condition and is eliminated from the matrix. The residual method must be used when this Dirichlet boundary condition is used as a parameter in automatic continuation sequences.

### Examples#

The following is a sample card for applying a Dirichlet condition on the tension for a shell equation:

BC = SH_TENS NS 100 10.


This condition sets a tension of 10.0 at Nodeset 100.

No Discussion.

### References#

GT-027.1: GOMA’s Shell Structure Capability: User Tutorial (GT-027.1)

## SH_K#

BC = SH_K NS <bc_id> <float1> [float2]


### Description / Usage#

(DC/shell_curvature)

This Dirichlet boundary condition specification is used to set a curvature to the inextensible shell equations (see EQ = shell_tension and EQ = shell_curvature) at an endpoint. This boundary condition can be applied in two dimensions only, and only to the endpoint of a bar-type element:

 SH_K Boundary condition name () that defines the shell curvature. NS Type of boundary condition (), where NS denotes node set in the EXODUS II database. Note that this must be a single-node node set representing and endpoint to a bar element type. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. Value of curvature. [float2] An optional parameter (that serves as a flag to the code for a Dirichlet boundary condition). If a value is present, and is not -1.0, the condition is applied as a residual equation. Otherwise, it is a “hard set” condition and is eliminated from the matrix. The residual method must be used when this Dirichlet boundary condition is used as a parameter in automatic continuation sequences.

### Examples#

The following is a sample card for applying a Dirichlet condition on the curvature for a shell equation:

BC = SH_K NS 100 0.


This condition sets a curvature of zero at Nodeset 100.

No Discussion.

### References#

GT-027.1: GOMA’s Shell Structure Capability: User Tutorial (GT-027.1)

## SH_FLUID_STRESS#

BC = SH_FLUID_STRESS SS <bc_id> <float>


### Description / Usage#

(PCC/VECTOR MOMENTUM)

Used for fluid-structure interaction problems with structural shell elements, the SH_FLUID_STRESS condition equates the normal traction (the tangential and normal force components, per unit area) between adjacent fluid and solid structure. This condition is only to be used on boundaries between regions of ARBITRARY mesh motion with fluid momentum equations: see Mesh Motion and EQ cards. With this boundary condition, the local residual and Jacobian contributions from the fluid mechanics momentum equations (on the ARBITRARY side of the boundary) are added into weak form of the residual and Jacobian entries for the solid structural equations (see EQ = shell_curvature and EQ = shell_tension). All elements on both sides of the interface must have the same element type, i.e., the same order of interpolation and basis functions, e.g., Q1 fluid and Q1 (bar element) for shell. Q2 fluid momentum and Q2 (bar element) for the shell equations. Also, such interfaces must be defined as a mesh side set attached to the bulk fluid elements (most mesh generators will not allow for side sets in bar or sheet elements).

Definitions of the input parameters are as follows:

 SH_FLUID_STRESS Name of the boundary condition (). SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (side set in EXODUS II) in the problem domain. Scale factor for stress balance for non-dimensionalization. This parameter, which multiplies the liquid phase contribution and should be set to 1.0 if there is no nondimensional treatment.

### Examples#

The following is a sample input card:

BC = SH_FLUID_STRESS SS 5 1.0


In this example, side set 5 is a boundary between a solid blade and a liquid; material 2 is the rubber blade, and material 1 is the fluid. Along that blade, a companion boundary condition of the form

BC = NO_SLIP SS 5 2 1


should also be applied.

### Technical Discussion#

The functional form of the boundary condition is:

where $$\underline{T}$$ is the fluid phase stress tensor given by any one of the specified fluid-phase constitutive equations, and $$\underline\sigma$$ is the solid-phase stress tensor, also given by any one of the solid-phase constitutive equation (see material file specifications). $$\lambda$$ is a scaling factor that defaults to unity (and is usually best taken as such unless some scaling is invoked).

This balance is applied to the weak form of the solid-phase momentum residuals, from the fluid phase, viz. in the fluid-phase, the fluid-stress at the interface is added to the solid-phase momentum residuals. As mentioned above, this condition usually needs to be supplemented by a statement of mass conservation across the interface, which will depend on whether the solid phase is of CONTINUOUS or POROUS media (see Media Type card).

### FAQs#

• Troubleshooting 1: This boundary condition requires that the side set contain elements from both the fluid and the solid side of the interface. For the FASTQ tool, this is the default case; for CUBIT and possibly other related tools, this can be forced on the side set definition options. Interestingly, the boundary condition does work if the side set is attached to the fluid phase only, but just due to the way in which it is applied.

• Troubleshooting 2: This boundary condition does not enforce mass conservation. A combination of NO_SLIP or VELO_NORMAL/VELO_TANGENT must be invoked to achieve a material surface. For the latter, care must be taken to maintain the application of the VELO_NORMAL condition after a remesh. This condition is applied only to one side of the interface and depends on the ss_to_blks connectivity structure; it may be necessary to force its application, especially after remeshes. To be sure that the proper set of conditions is being applied, look at the BC_dup.txt file for nodes along the interface.

### References#

GT-003.1: Roll coating templates and tutorial for GOMA and SEAMS, February 29, 2000, P. R. Schunk and Matt Stay

GT-006.3: Slot and Roll coating with remeshing templates and tutorial for GOMA and CUBIT/MAPVAR, August 3, 1999, R. R. Lober and P. R. Schunk

## LUB_PRESS#

BC = LUB_PRESS NS <bc_id> <float_list>


### Description / Usage#

This boundary condition card applies a lubrication pressure to the boundary of a shellelement sheet. The corresponding equation is EQ=lubp. The boundary condition is applied to a node set.

 LUB_PRESS Name of boundary condition. NS Type of boundary condition (), where NS denotes node set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. lub_p, the value of lubrication pressure at the boundary. [float2] Optional floating point number set between 0.0 and 1.0 which serves as a flag to the code for a Dirichlet boundary condition. If this value is present, and is not 1.0, the condition is applied as a residual equation. Otherwise, it is “hard-set” condition and is eliminate from the matrix. The residual method must beused when this Dirichlet boundary condition is used as a parameter in automatic continuation sequences.

### Examples#

Following is a sample card:

BC = LUB_PRESS NS   100 100.


This condition applies a lubrication pressure of 100.0 at nodeset 100.

### Technical Discussion#

The equation applied at the specified nodeset in place of Reynold’s lubrication equation for confined flow. Note that it is not to be used for the film-flow lubrication equations.

BC = GRAD_LUB_PRESS SS <bc_id> <float1>


### Description / Usage#

(WIC/R_LUBP)

This boundary condition card applies free boundary condition, akin to Papanastasiou et al. (1992) for the fluid momentum, at the boundary of a shell-element sheet. The boundary condition is applied to a sideset.

 GRAD_LUB_PRESS Name of boundary condition. SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. Flowrate in L^2/t. Usually set for NOBC effect.

### Examples#

Following is a sample card:

BC = GRAD_LUB_PRESS SS   100 0.


This condition applied at sideset 100.

No Discussion.

## SHELL_FILMP#

BC = SHELL_FILMP NS <bc_id> <float_list>


### Description / Usage#

This boundary condition card applies a film pressure to the boundary of a shell-element sheet. The corresponding equation is EQ=shell_filmp. The boundary condition is applied to a node set.

 SHELL_FILMP Name of boundary condition. NS Type of boundary condition (), where NS denotes node set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. shell_filmp, the value of lubrication pressure at the boundary. [float2] Optional floating point number set between 0.0 and 1.0 which serves as a flag to the code for a Dirichlet boundary condition. If this value is present, and is not 1.0, the condition is applied as a residual equation. Otherwise, it is “hard-set” condition and is eliminate from the matrix. The residual method must beused when this Dirichlet boundary condition is used as a parameter in automatic continuation sequences.

### Examples#

Following is a sample card:

BC = SHELL_FILMP NS   100 100.


This condition applies a film pressure of 100.0 at nodeset 100.

### Technical Discussion#

The equation applied at the specified nodeset in place of the film-flow lubrication equation.

## SHELL_FILMH#

BC = SHELL_FILMH NS <bc_id> <float_list>


### Description / Usage#

(DC/R_SHELL_FILMH)

This boundary condition card applies a film height to the boundary of a shell-element sheet. The corresponding equation is EQ=shell_filmh. The boundary condition is applied to a node set.

 SHELL_FILMH Name of boundary condition. NS Type of boundary condition (), where NS denotes node set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. shell_filmh, the value of film thickness at the boundary. [float2] Optional floating point number set between 0.0 and 1.0 which serves as a flag to the code for a Dirichlet boundary condition. If this value is present, and is not 1.0, the condition is applied as a residual equation. Otherwise, it is “hard-set” condition and is eliminate from the matrix. The residual method must beused when this Dirichlet boundary condition is used as a parameter in automatic continuation sequences.

### Examples#

Following is a sample card:

BC = SHELL_FILMH NS   100 1.


This condition applies a film height of 1.0 at nodeset 100.

### Technical Discussion#

The equation applied at the specified nodeset in place of the film-flow height equation.

## SHELL_PARTC#

BC = SHELL_PARTC NS <bc_id> <float_list>


### Description / Usage#

(DC/R_SHELL_PARTC)

This boundary condition card applies a particle volume fraction to the boundary of a shell-element sheet. The corresponding equation is EQ=shell_filmh. The boundary condition is applied to a node set.

 SHELL_PARTC Name of boundary condition. NS Type of boundary condition (), where NS denotes node set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. shell_partc, the value of film thickness at the boundary. [float2] Optional floating point number set between 0.0 and 1.0 which serves as a flag to the code for a Dirichlet boundary condition. If this value is present, and is not 1.0, the condition is applied as a residual equation. Otherwise, it is “hard-set” condition and is eliminate from the matrix. The residual method must beused when this Dirichlet boundary condition is used as a parameter in automatic continuation sequences.

### Examples#

Following is a sample card:

BC = SHELL_PARTC NS   100 0.


This condition applies a particles volume fractioin of 0.0 at nodeset 100.

### Technical Discussion#

The equation applied at the specified nodeset in place of the particles conservation equation.

### References#

No References.

BC = BC = SHELL_GRAD_FP SS <bc_id> <float_list>


### Description / Usage#

This boundary condition card applies a volumetric flux of liquid film to the boundary of a shell-element sheet. The corresponding equation is EQ=shell_filmp. The boundary condition is applied to a node set.

 SHELL_GRAD_FP Name of boundary condition. SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. volumetric flux

### Examples#

Following is a sample card:

BC = SSHELL_GRAD_FP SS   100 0.0


This condition applies a particles volume flux of 0.0 at nodeset 100.

### Technical Discussion#

The actual weighted residual equation that is applied to node on the surface is

where $$\phi_i$$ is the finite element trial function, n is the outward-pointing normal to the surface, and q is the volumetric flux specified in the <float1>. Careful attention should be given for the sign of q. The sign convention is that q is positive when the flow is exiting the boundary and negative when entering the boundary.

The condition replaces the residual equation shell_filmp at the boundary.

BC = BC = SHELL_GRAD_FP_NOBC SS <bc_id>


### Description / Usage#

This boundary condition card applies free boundary condition, akin to Papanastasiou et al. (1992) for the fluid momentum, at the boundary of a shell-element sheet. The boundary condition is applied to a sideset.

 SHELL_GRAD_FP_NOBC Name of boundary condition. SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain.

### Examples#

Following is a sample card:

BC = SSHELL_GRAD_FP_NOBC SS   100


This condition applied at sideset 100.

### Technical Discussion#

• The finite element formulation of the first equation of the film profile equation boundary integral in the form of

• This condition is similar to the SHELL_GRAD_FP boundary condition, except that the condition is now a weak integrated condition that is added to the residual equations, instead of replacing them and the flux is no longer specified.

BC = BC = SHELL_GRAD_FH SS <bc_id> <float_list>


### Description / Usage#

This boundary condition card sets a slope to the liquid film at the boundary of a shellelement sheet. The corresponding equation is EQ=shell_filmh. The boundary condition is applied to a node set.

 SHELL_GRAD_FH Name of boundary condition. SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. slope

### Examples#

Following is a sample card:

BC = SSHELL_GRAD_FH SS   100 0.0


This condition applies a film slope of 0.0 at nodeset 100.

### Technical Discussion#

• he actual weighted residual equation that is applied to node on the surface is

where $$\phi_i$$ is the finite element trial function, n is the outward-pointing normal to the surface, $$\Sigma$$ and is the slope specified in the <float1>.

• The condition replaces the residual equation shell_filmh at the boundary.

BC = BC = SHELL_GRAD_FH_NOBC SS <bc_id>


### Description / Usage#

This boundary condition card applies free boundary condition, akin to Papanastasiou et al. (1992) for the fluid momentum, at the boundary of a shell-element sheet, in terms of the slope of a thin Reynolds film. The boundary condition is applied to a sideset.

 SHELL_GRAD_FH_NOBC Name of boundary condition. SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain.

### Examples#

Following is a sample card:

BC = SSHELL_GRAD_FH_NOBC SS   100


This condition applied at sideset 100.

### Technical Discussion#

• The finite element formulation of the second equation of film profile equation generates boundary integral in the form of

• This condition is similar to the SHELL_GRAD_FH boundary condition, except that the condition is now a weak integrated condition that is added to the residual equations, instead of replacing them and the flux is no longer specified.

BC = BC = SHELL_GRAD_PC SS <bc_id> <float_list>


### Description / Usage#

This boundary condition card allows the user to set volumetric flux of particles inside liquid film at the boundary of a shell-element sheet. The corresponding equation is EQ=shell_partc. The boundary condition is applied to a side set.

 SHELL_GRAD_PC Name of boundary condition. SS Type of boundary condition (), where SS denotes side set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. particle flux

### Examples#

Following is a sample card:

BC = SHELL_GRAD_PC SS   100 1.


This condition applied at sideset 100. and sets a particle flux to 1.0

### Technical Discussion#

• The actual weighted residual equation that is applied to node on the surface is

where $$\phi_i$$ is the finite element trial function, n is the outward-pointing normal to the surface, $$J_p$$ and is the particles flux specified in the <float1>.

• The condition replaces the residual equation shell_partc at the boundary.

## SHELL_LUBP_SOLID#

BC = SH_LUBP_SOLID SS <bc_id> <float1>


### Description / Usage#

(WIC/R_MESH1/R_MESH2/RMESH3)

This vector boundary condition card balances the stress in an abutting continuum elastic solid with the lubrication forces (pressure and shear) in a surface shell. The boundary condition is applied to a sideset. Please see notes below on the sideset features which must be specified.

 SH_LUBP_SOLID Name of boundary condition. SS Type of boundary condition (), where SS denotes sideset in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (nodeset in EXODUS II) in the problem domain. Scaling factor. Normally set this to 1.0, unless a stressbalance scale is required due to nondimensionalization.

### Examples#

Following is a sample card:

BC = SH_LUBP_SOLID SS   100 1.0


This boundary condition is applied at sideset 100.

### Technical Discussion#

• The mathematical form of the boundary condition is

• This condition is similar to FLUID_SOLID and SOLID_FLUID boundary conditions for the case of fluid-structure interaction between two continuum regions, one fluid and one solid.

• Note that the sideset as generated in CUBIT or related software is actually attached to the continuum domain and not the shell face, as those faces (top and bottom of sheet and not the edges) are not true finite element sides. Most mesh generators will not allow sidesets to be include shell element faces. GOMA figures out the right thing to do.

## SHELL_TEMP#

BC = SHELL_TEMP NS <bc_id> <float_list>


### Description / Usage#

(DC/R_SHELL_ENERGY)

This boundary condition card applies a shell temperature to the boundary of a shellelement sheet. The corresponding equation is EQ=shell_energy. The boundary condition is applied to a node set.

 SHELL_TEMP Name of boundary condition. NS Type of boundary condition (), where NS denotes node set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. SHELL_TEMP, the value of temperature at the boundary. [float2] Optional floating point number set between 0.0 and 1.0 which serves as a flag to the code for a Dirichlet boundary condition. If this value is present, and is not 1.0, the condition is applied as a residual equation. Otherwise, it is “hard-set” condition and is eliminated from the matrix. The residual method must beused when this Dirichlet boundary condition is used as a parameter in automatic continuation sequences.

### Examples#

Following is a sample card:

BC = SHELL_TEMP 100 1.0


This boundary condition is applied at nodeset 100.

### Technical Discussion#

• The equation applied at the specified nodeset in place of the shell-temperature equation.

No References.

## SHELL_OPEN_PRESS, SHELL_OPEN_PRESS_2#

BC = SHELL_OPEN_PRESS NS <bc_id> <float_list>

BC = SHELL_OPEN_PRESS_2 NS <bc_id> <float_list>


### Description / Usage#

(DC/R_SHELL_SAT_OPEN or SHELL_SAT_OPEN_2)

This Dirichlet boundary condition card applies a shell liquid phase pressure to the boundary of a shell-element sheet. The corresponding equation is EQ=shell_sat_open or correspondingly shell_sat_open_2, depending on which layer. The boundary condition is applied to a node set.

 SHELL_OPEN_PRESS Name of boundary condition. NS Type of boundary condition (), where NS denotes node set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (node set in EXODUS II) in the problem domain. SHELL_OPEN_PRESSURE, the value of the liquid phase pressure at the boundary. [float2] Optional floating point number set between 0.0 and 1.0 which serves as a flag to the code for a Dirichlet boundary condition. If this value is present, and is not 1.0, the condition is applied as a residual equation. Otherwise, it is “hard-set” condition and is eliminated from the matrix. The residual method must beused when this Dirichlet boundary condition is used as a parameter in automatic continuation sequences.

### Examples#

Following is a sample card:

BC = SHELL_OPEN_PRESS 100 1.0


This boundary condition is applied at nodeset 100.

### Technical Discussion#

• The equation applied at the specified nodeset in place of the shell-sat-open equation.

No References.

## LUBP_SH_FP_FLUX#

C = LUBP_SH_FP_FLUX SS <bc_id> <int1> <int2>


### Description / Usage#

(COLLOC/R_SHELL_FILMP)

This boundary condition card matches the mass flux in one region of confined flow (lubp) to the mass flux from a second region of film flow (shell_filmp). The flux matching is handled as a sideset between two shell regions. In this way both equations can be coupled for exit or entrance flows. The boundary condition is applied in collocated form, and replaces the R_SHELL_FILMP equation.

 LUBP_SH_FP_FLUX Name of boundary condition. SS Type of boundary condition (), where SS denotes node set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (side set in EXODUS II) in the problem domain. Block id of mesh material which invokes the lubp equation. Block id of mesh material which invokes the shell_filmp equation.

### Examples#

Following is a sample card:

BC = LUBP_SH_FP_FLUX SS   100 2 1


This condition applies the matching tie condition at a side set boundary between block 2 (which invokes the EQ = lubp equation) and block 1 (which invokes the EQ=shell_filmp equation).

### Technical Discussion#

The best example of the use of this equation is the exit of a metered coating flow. It must be used together with a pressure-matching condition LUBP_SH_FP_MATCH.

## LUBP_SH_FP_MATCH#

C = LUBP_SH_FP_MATCH SS <bc_id> <int1> <int2>


### Description / Usage#

(STRONG_INT_SURF/R_LUBP)

This boundary condition card matches the pressure in one region of confined flow (lubp) to the pressure from a second region of film flow (shell_filmp). The pressure matching is handled as a sideset between two shell regions. In this way both equations can be coupled for exit or entrance flows. The boundary condition is applied in collocated form, and replaces the R_LUBP equation.

 LUBP_SH_FP_FLUX Name of boundary condition. SS Type of boundary condition (), where SS denotes node set in the EXODUS II database. The boundary flag identifier, an integer associated with that identifies the boundary location (side set in EXODUS II) in the problem domain. Block id of mesh material which invokes the lubp equation. Block id of mesh material which invokes the shell_filmp equation.

### Examples#

Following is a sample card:

BC = LUBP_SH_FP_MATCH SS   100 2 1


This condition applies the matching tie condition at a side set boundary between block 2 (which invokes the EQ = lubp equation) and block 1 (which invokes the EQ=lubp equation).

### Technical Discussion#

The best example of the use of this equation is the exit of a metered coating flow. It must be used together with a flux-matching condition LUBP_SH_FP_FLUX.