# MOX Pore Velocity Calculation

Calculates pore speed. Used with kernel MOXPoreContinuity.

## Description

Pore speed is calculated in this class [MOXPoreVelocity], which is used in the kernel MOXPoreContinuity shown in the second term of the following equation:

(1)

where is the porosity, is the pore velocity, is the temperature, and is the diffusion coefficient MOXPoreDiffusion. Usually, the temperature gradient is included in the pore velocity term, but here, the temperature gradient is written separately to emphasize the dependence of pore migration on temperature gradient. The equation for pore speed is (Sens, 1972),

(2)

under construction

This class is still under development!

See bison/test/mox_pore_velocity/ for examples of how this class should be used.

## Input Parameters

• temperatureCoupled Temperature

C++ Type:std::vector

Description:Coupled Temperature

### Required Parameters

• scale_factor1scale the velocity to account for uncertainty

Default:1

C++ Type:double

Description:scale the velocity to account for uncertainty

• limit1limit for pore velocity in m/s

Default:1

C++ Type:double

Description:limit for pore velocity in m/s

• computeTrueWhen false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the Material via MaterialPropertyInterface::getMaterial(). Non-computed Materials are not sorted for dependencies.

Default:True

C++ Type:bool

Description:When false, MOOSE will not call compute methods on this material. The user must call computeProperties() after retrieving the Material via MaterialPropertyInterface::getMaterial(). Non-computed Materials are not sorted for dependencies.

• boundaryThe list of boundary IDs from the mesh where this boundary condition applies

C++ Type:std::vector

Description:The list of boundary IDs from the mesh where this boundary condition applies

• pore_velocitycalculated in materials property

C++ Type:double

Description:calculated in materials property

• blockThe list of block ids (SubdomainID) that this object will be applied

C++ Type:std::vector

Description:The list of block ids (SubdomainID) that this object will be applied

### Optional Parameters

• enableTrueSet the enabled status of the MooseObject.

Default:True

C++ Type:bool

Description:Set the enabled status of the MooseObject.

• use_displaced_meshFalseWhether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

Default:False

C++ Type:bool

Description:Whether or not this object should use the displaced mesh for computation. Note that in the case this is true but no displacements are provided in the Mesh block the undisplaced mesh will still be used.

• control_tagsAdds user-defined labels for accessing object parameters via control logic.

C++ Type:std::vector

Description:Adds user-defined labels for accessing object parameters via control logic.

• seed0The seed for the master random number generator

Default:0

C++ Type:unsigned int

Description:The seed for the master random number generator

• implicitTrueDetermines whether this object is calculated using an implicit or explicit form

Default:True

C++ Type:bool

Description:Determines whether this object is calculated using an implicit or explicit form

• constant_onNONEWhen ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeSubdomainProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

Default:NONE

C++ Type:MooseEnum

Description:When ELEMENT, MOOSE will only call computeQpProperties() for the 0th quadrature point, and then copy that value to the other qps.When SUBDOMAIN, MOOSE will only call computeSubdomainProperties() for the 0th quadrature point, and then copy that value to the other qps. Evaluations on element qps will be skipped

• output_propertiesList of material properties, from this material, to output (outputs must also be defined to an output type)

C++ Type:std::vector

Description:List of material properties, from this material, to output (outputs must also be defined to an output type)

• outputsnone Vector of output names were you would like to restrict the output of variables(s) associated with this object

Default:none

C++ Type:std::vector

Description:Vector of output names were you would like to restrict the output of variables(s) associated with this object

## References

1. P. F. Sens. The kinetics of pore movement in uo2 fuel rods. Journal of Nuclear Materials, 43:293â€“307, 1972. URL: http://www.sciencedirect.com/science/article/pii/002231157290061X, doi:https://doi.org/10.1016/0022-3115(72)90061-X.[BibTeX]