- lengthLength of each axial section [m]
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Length of each axial section [m]
- n_elemsNumber of elements in each axial section
C++ Type:std::vector<unsigned int>
Unit:(no unit assumed)
Controllable:No
Description:Number of elements in each axial section
- n_part_elemsNumber of elements of each radial region
C++ Type:std::vector<unsigned int>
Unit:(no unit assumed)
Controllable:No
Description:Number of elements of each radial region
- namesName of each radial region
C++ Type:std::vector<std::string>
Unit:(no unit assumed)
Controllable:No
Description:Name of each radial region
- orientationDirection of axis from start position to end position (no need to normalize)
C++ Type:libMesh::VectorValue<double>
Unit:(no unit assumed)
Controllable:No
Description:Direction of axis from start position to end position (no need to normalize)
- positionStart position of axis in 3-D space [m]
C++ Type:libMesh::Point
Unit:(no unit assumed)
Controllable:No
Description:Start position of axis in 3-D space [m]
- widthsWidth of each radial region [m]
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Width of each radial region [m]
HeatStructureCylindrical
This component is a 2D heat structure that has axisymmetry; thus it is either a cylinder or cylindrical shell.
Usage
The initial temperature is given by the function parameter "initial_T".
The parameters "position", "orientation", "length", "n_elems", and "axial_region_names" are discussed in Axial Discretization.
The parameters "names", "widths", and "n_part_elems" are discussed in Radial Discretization.
There are two options for specification of the thermal properties on the heat structure:
Create a SolidProperties object for each unique heat structure material, and then provide "solid_properties" which corresponds to the
SolidProperties
object to use in each transverse region (each entry corresponds to the equally indexed entry in "names") and "solid_properties_T_ref", which provides the temperatures at which to evaluate the densities, since a constant density is to be used in each region, due to heat structures having a non-deformable mesh.Create Materials object(s) supplying the following material properties on all blocks (see Blocks and Boundaries) of the heat structure mesh:
Material Property Symbol Description density
Density [kg/m] specific_heat
Specific heat capacity [J/(kg-K)] thermal_conductivity
Thermal conductivity [W/(m-K)]
If the domain has some inner radius, then this is specified with "inner_radius"; otherwise, it is assumed to be a solid cylinder.
Input Parameters
- axial_region_namesNames to assign to axial regions
C++ Type:std::vector<std::string>
Unit:(no unit assumed)
Controllable:No
Description:Names to assign to axial regions
- initial_TInitial temperature [K]
C++ Type:FunctionName
Unit:(no unit assumed)
Controllable:No
Description:Initial temperature [K]
- inner_radius0Inner radius of the heat structure [m]
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Inner radius of the heat structure [m]
- num_rods1Number of rods represented by this heat structure
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Number of rods represented by this heat structure
- offset_mesh_by_inner_radiusFalseOffset the mesh by the inner radius?
Default:False
C++ Type:bool
Unit:(no unit assumed)
Controllable:No
Description:Offset the mesh by the inner radius?
- rotation0Angle of rotation about the x-axis [degrees]
Default:0
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Angle of rotation about the x-axis [degrees]
- scaling_factor_temperature1Scaling factor for solid temperature variable.
Default:1
C++ Type:double
Unit:(no unit assumed)
Controllable:No
Description:Scaling factor for solid temperature variable.
- solid_propertiesSolid properties object name for each radial region
C++ Type:std::vector<UserObjectName>
Unit:(no unit assumed)
Controllable:No
Description:Solid properties object name for each radial region
- solid_properties_T_refDensity reference temperatures for each radial region. This is required if 'solid_properties' is provided. The density in each region will be a constant value computed by evaluating the density function at the reference temperature.
C++ Type:std::vector<double>
Unit:(no unit assumed)
Controllable:No
Description:Density reference temperatures for each radial region. This is required if 'solid_properties' is provided. The density in each region will be a constant value computed by evaluating the density function at the reference temperature.
Optional Parameters
- control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Unit:(no unit assumed)
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
- enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Unit:(no unit assumed)
Controllable:No
Description:Set the enabled status of the MooseObject.
Advanced Parameters
Mesh
Axial Discretization
This component generates a mesh along a line segment in 3D space. The line segment is defined with a "start" point , corresponding to either end, the direction to the other end, and the distance in that direction, . Thus the other end of the line segment is
These quantities are defined using the following parameters:
"position": the "start" point ,
"orientation": the direction (which gets automatically normalized), and
"length": the length(s) that sum to .
The most basic mesh specification is given by a single value for the parameters "length" and "n_elems", which correspond to the length of the component and number of uniformly-sized elements to use. For example, the following parameters would specify a total length m, divided into 100 elements (each with width 0.5 m):
The "length" and "n_elems" parameters can also be supplied with multiple values. Multiple values correspond to splitting the length into segments that can have different element sizes. However, within each segment, the discretization is assumed uniform. The numbers of elements in each segment are specified with the parameter "n_elems", with entries corresponding to the entries in "length". For example, the following would also specify a total length m with 100 total elements, but in this case the first 10 m have 40 elements of size 0.25 m, whereas the last 40 m have 60 elements of size m.
When using more than one entry in the "length" and "n_elems" parameters, the parameter "axial_region_names" is used to provide names that are used in the generation of corresponding block and boundary names (see Blocks and Boundaries).
Radial Discretization
The domain may be divided up into any number (say, ) of regions in the radial direction, which each get their own subdomain names and may use different thermal properties. For example, if the domain were a fuel rod, two regions could be used: the fuel itself and the cladding. The parameters "names", "widths", and "n_part_elems" are all lists of size , with entries corresponding to each radial region, ordered from the side closest to the axis of the component. "names" is a list of names to assign to each region, which will be used to create subdomain names and to refer to the regions in some objects. The radial width (thickness) of each region is specified using "widths", and the number of radial elements in each region is given by "n_part_elems".
Blocks and Boundaries
This component creates the following blocks, where <cname>
is the user-given name of the component:
Block | Description |
---|---|
<cname>:<rname> | The radial region <rname> |
This component creates the following boundaries:
Boundary | Description |
---|---|
<cname>:inner | The innermost radial boundary |
<cname>:outer | The outermost radial boundary |
<cname>:<aname>:inner | The innermost radial boundary in the axial section <aname> |
<cname>:<aname>:outer | The outermost radial boundary in the axial section <aname> |
<cname>:start | The axial boundary of the end corresponding to the position parameter |
<cname>:end | The axial boundary of the end opposite to the position parameter |
<cname>:<rname>:start | The axial boundary of the end corresponding to the position parameter in the radial region <rname> |
<cname>:<rname>:end | The axial boundary of the end opposite to the position parameter in the radial region <rname> |
<cname>:<rname1>:<rname2> | The radial boundary between the radial regions <rname1> and <rname2> |
<cname>:<rname>:<aname1>:<aname2> | The axial boundary in radial region <rname> between the axial regions <aname1> and <aname2> |
Variables
The following variables are created:
Variable | Symbol | Description |
---|---|---|
T_solid | Temperature [K] |
Formulation
The heat conduction equation is the following: where
is density,
is specific heat capacity,
is thermal conductivity,
is temperature, and
is a volumetric heat source.
Multiplying by a test function and integrating by parts over the domain gives where is the boundary of the domain .