Boundary conditions for induction-less model in fluid domains

Boundary conditions available for the induction-less model in fluid domains are described below. Their usage in the Electric Potential sublist of the Data block is illustrated through representative examples.

The Electric Potential sublist is required for IncompressibleBoundaryFlux boundaries when Build Inductionless MHD Equation is enabled in the fluid physics block.

Fixed boundary
Type
Type:

string

Value:

Fixed

Usage:

Required

Description:

Fixed electric-potential boundary condition with optional linear time ramping.

Final Value
Type:

double

Value:

\([-\infty,\infty]\)

Usage:

Required

Description:

Final electric potential value in Volts \((V)\) to set at the boundary.

Initial Value
Type:

double

Value:

\([-\infty,\infty]\)

Usage:

Optional

Default:

Final Value

Description:

Initial electric potential value in Volts \((V)\) used for linear time ramping.

Time Initial
Type:

double

Value:

\([0,\infty]\)

Usage:

Optional

Default:

0.0

Description:

Time in seconds \((s)\) to start linear ramping from Initial Value.

Time Final
Type:

double

Value:

\([0,\infty]\)

Usage:

Optional

Default:

1.0E-06

Description:

Time in seconds \((s)\) to complete linear ramping to Final Value.

Listing 32 Fixed electric-potential boundary from mhd_2d_joule_heating.xml.
 1<ParameterList name="Boundary Conditions">
 2  <ParameterList>
 3    <Parameter name="Sideset ID" type="string" value="left"/>
 4    <Parameter name="Element Block ID" type="string" value="eblock-0_0"/>
 5    <Parameter name="Strategy" type="string" value="IncompressibleBoundaryFlux"/>
 6    <ParameterList name="Data">
 7      <ParameterList name="Navier-Stokes">
 8        <Parameter name="Type" type="string" value="No-Slip"/>
 9        <Parameter name="Wall Temperature" type="double" value="500.0"/>
10      </ParameterList> <!-- Navier-Stokes -->
11      <ParameterList name="Electric Potential">
12        <Parameter name="Type" type="string" value="Fixed"/>
13        <Parameter name="Final Value" type="double" value="1.5"/>
14      </ParameterList> <!-- Electric Potential -->
15      <ParameterList name="Penalty Parameters">
16        <Parameter name="temperature" type="double" value="10.0"/>
17        <Parameter name="electric_potential" type="double" value="1000.0"/>
18      </ParameterList> <!-- Penalty Parameters -->
19    </ParameterList> <!-- Data -->
20  </ParameterList> <!-- -->
21</ParameterList> <!-- Boundary Conditions -->
Electric-potential insulating wall boundary
Type
Type:

string

Value:

ElectricPotentialInsulatingWall

Usage:

Required

Description:

Insulating wall boundary condition that sets \(\nabla \phi \cdot \vec{n} = 0\).

Listing 33 Electric-potential insulating wall boundary from mhd_2d_joule_heating.xml.
 1<ParameterList name="Boundary Conditions">
 2  <ParameterList>
 3    <Parameter name="Sideset ID" type="string" value="top, bottom"/>
 4    <Parameter name="Element Block ID" type="string" value="eblock-0_0"/>
 5    <Parameter name="Strategy" type="string" value="IncompressibleBoundaryFlux"/>
 6    <ParameterList name="Data">
 7      <ParameterList name="Navier-Stokes">
 8        <Parameter name="Type" type="string" value="No-Slip"/>
 9        <Parameter name="Temperature Profile" type="string" value="Adiabatic"/>
10      </ParameterList> <!-- Navier-Stokes -->
11      <ParameterList name="Electric Potential">
12        <Parameter name="Type" type="string" value="ElectricPotentialInsulatingWall"/>
13      </ParameterList> <!-- Electric Potential -->
14      <ParameterList name="Penalty Parameters">
15        <Parameter name="temperature" type="double" value="10.0"/>
16        <Parameter name="electric_potential" type="double" value="1000.0"/>
17      </ParameterList> <!-- Penalty Parameters -->
18    </ParameterList> <!-- Data -->
19  </ParameterList> <!-- -->
20</ParameterList> <!-- Boundary Conditions -->
Electric-current-density insulating boundary
Type
Type:

string

Value:

ElectricCurrentDensityInsulating

Usage:

Required

Description:

Insulating boundary condition that accounts for velocity and external magnetic field and sets \((\nabla \phi - \vec{u} \times \vec{B}) \cdot \vec{n} = 0\).

Listing 34 Electric-current-density insulating boundary from mhd_hunt_cw0p05_re_10_ha_300.xml.
 1<ParameterList name="Boundary Conditions">
 2  <ParameterList>
 3    <Parameter name="Sideset ID" type="string" value="top, bottom"/>
 4    <Parameter name="Element Block ID" type="string" value="fluid_block"/>
 5    <Parameter name="Strategy" type="string" value="IncompressibleBoundaryFlux"/>
 6    <ParameterList name="Data">
 7      <ParameterList name="Navier-Stokes">
 8        <Parameter name="Type" type="string" value="No-Slip"/>
 9      </ParameterList> <!-- Navier-Stokes -->
10      <ParameterList name="Electric Potential">
11        <Parameter name="Type" type="string" value="ElectricCurrentDensityInsulating"/>
12      </ParameterList> <!-- Electric Potential -->
13    </ParameterList> <!-- Data -->
14  </ParameterList> <!-- -->
15</ParameterList> <!-- Boundary Conditions -->