Values

This section lists all the boundary values that are available for energy models in Simcenter STAR-CCM+ and it provides a detailed reference for the methods of setting them.

  • Ambient temperature
  • External emissivity
  • External reflectivity
  • Heat flux
  • Heat transfer coefficient
  • Static temperature
  • Thermal resistance
  • Total temperature
  • User wall heat flux coefficient, A
  • User wall heat flux coefficient, B
  • User wall heat flux coefficient, C
  • User wall heat flux coefficient, D

It also lists region values:

  • Anisotropic thermal conductivity
  • Volumetric heat source
  • Heat source
  • Specific heat source
  • Energy source pressure derivative
  • Energy source temperature derivative
  • Energy source velocity derivative
  • Solid density
  • Solid specific heat
  • Solid thermal conductivity
  • Convective Velocity

Boundary values are selected according to the boundary type, or by methods that are selected in corresponding nodes in the boundary conditions node. The boundary types that are available are listed in the Boundary Type section of each model.

Most of the boundary values listed here can be entered as scalar profiles using standard methods. Exceptions are noted. If the scalar profile takes the form of a user-defined field function, use a function of the algebraic formh=vH/V or h=vH/S where:

  • h is heat source for the cell.
  • H is total heat source in volume or on surface, as defined in the field function.
  • v is cell volume.
  • s is cell surface.
  • V is total volume.
  • S is total surface.

Boundary Values

Ambient temperature
This value node is visible if Convection is selected as the Method property for the Thermal Specification node of the Conditions node. It is input as a scalar profile.
External emissivity
Certain energy and radiation models use this boundary value. It is only visible if external radiation is enabled and is entered as a scalar profile.
External reflectivity
Certain energy and radiation models use this boundary value. It is only visible if external radiation is enabled. It can be entered as a scalar profile or can be calculated automatically using the Auto-Calculate method, which is available for reflectivity.
Heat flux
This value node is only visible if Heat Flux is selected as the Method property for the Thermal Specification node of the Conditions node. It is input as a scalar profile in W/m2. Specify a positive heat flux value for heat flowing into the domain, or a negative value for heat flowing out.
Heat transfer coefficient
Energy models require this boundary value. It is visible if the Convection method is chosen as the Thermal Specification and is entered as a scalar profile.
Static temperature
The temperature of the boundary. This value node is visible if Temperature is selected as the Method property for the Thermal Specification node of the Conditions node. It is entered as a scalar profile.
Thermal resistance
This boundary value appears when the Convection method is chosen as the Thermal Specification. It functions in a manner similar to the Thermal Resistance baffle interface value.
Total temperature
The total temperature of the boundary. It is entered as a scalar profile. Not available in regions of type solid.See also Stagnation Inlet.
User wall heat flux coefficient, A | B | C | D
These boundary values Are available with energy models. They are only visible if the Specified method is chosen as the User Wall Heat Flux Coefficient Specification and is entered as a scalar profile. By default it has a constant value of zero.

Region Values

Anisotropic thermal conductivity
This value node is added to a solid region when the thermal conductivity material property of a solid is set to the Anisotropic method. It is entered as a tensor profile. The method of the tensor profile is set by selecting the Anisotropic Thermal Conductivity node and using the drop-down menu in the Properties window.
Volumetric heat source
This node is added when the Energy Source Option region condition is set to Volumetric Heat Source. It is entered as a scalar profile.
Heat source
This value specifies the total heat source in W. It is available when you activate either the Heat Source Energy Source Option for a region, or the Heat Source Thermal Specification for a boundary.
Specific heat source
This node is added when the Energy Source Option region condition is set to Specific Heat Source. It is entered as a scalar profile.This value specifies the heat source in W/kg.
Energy source pressure derivative
This node represents the derivative of the Energy Source with respect to pressure. See S u in Eqn. (947). The derivative of the user source term is used to linearize Eqn. (947) . Its value is set to zero by default. Providing a value for the derivative helps stabilize the solution when the function for the source term is a function of pressure. If the source is constant, or not a function of pressure, leave this value at zero. The Energy Source Pressure Derivative is available when coupled flow is used. This object is added when the Energy Source Option region condition is set to Specified, and is entered as a scalar profile.
Energy source temperature derivative
This node represents linearization of the Energy Source with respect to temperature. See Su in Eqn. (947) (coupled) and sudV in Eqn. (1840) (segregated). The derivative of the user source term is used to linearize these equations. Its value is set to zero by default. Providing a value for the derivative helps stabilize the solution when the function for the source term is a function of temperature. If the source is constant, or not a function of temperature, leave this value at zero. The Energy Source Temperature Derivative is available when either coupled or segregated flow is used. This object is added when the Energy Source Option region condition is set to Specified, and is entered as a scalar profile.
Energy source velocity derivative
This node represents linearization of the Energy Source with respect to x-, y-, [z-] components of velocity.See Su in Eqn. (947) . The derivative of the user source term is used to linearize Eqn. (947) . Its value is set to zero by default. Providing a value for the derivative helps stabilize the solution when the energy source is a function of velocity. If the source is constant, or not a function of velocity, leave this value at zero. The Energy Source Velocity Derivative is available when coupled flow is used. This object is added when the Energy Source Option region condition is set to Specified, and is entered as a vector profile.
Solid density
This node is only available in regions of the porous type.The density that is provided here is used to specify the solid density ρsolid in Eqn. (1846). The fluid density ρfluid in Eqn. (1846) is the density property that is specified for the fluid continuum. It is entered as a scalar profile.
Solid specific heat
This node is only available in regions of the porous type. The specific heat that is provided here is used to specify the solid specific heat Cpsolid in Eqn. (1840). It is entered as a scalar profile.
Solid thermal conductivity
This node is only available in regions of the porous type.The thermal conductivity that is provided here is used to specify ksolid in Eqn. (1846). The fluid thermal conductivity kfluid in Eqn. (947) is extracted from the property that is specified for the fluid continuum. It is entered as a tensor profile, and it is possible to use field functions and other profile methods to define the components of the tensor.
Convective Velocity
This node, which has properties, is added when the Convective Velocity Option for a solid region has been set to Specified. Rotation is specified by providing a rotation axis, an origin for that axis, and a rotation rate. Translation is specified by providing the translation velocity. User-defined coordinate systems can be used when specifying quantities.
Properties
Direction
Provides a convective velocity field for the region.
Origin
The Cartesian position vector specifying the origin of the axis of rotation.
Coordinate System
Specifies the coordinate system (laboratory by default) for defining the origin and axis. The drop-down list of this property includes any local coordinate systems that exist in the simulation.
Rotation Rate
The rotation rate around the axis that is specified by Direction and Origin. This is additive with Translation Velocity.
Translation Velocity
The translation velocity of the region. This is additive with Rotation Rate.