Specifying Thermal and Radiative Boundary Conditions

You set thermal and radiative conditions for the regions' boundaries. You specify the radiative conditions by assigning surface materials to the boundaries. At the walls of the opaque and transparent components, you set a convective condition.

Between the connector support and the rear housing, a gap reduces the heat transfer. To model the gap, you set a contact resistance at the interface.

To specify thermal and radiative conditions:
  1. Specify the boundary conditions and values for the Air region:
    1. Multi-edit the following region nodes:
      • Air > Boundaries > Opaque Components/Air [1]
      • Air > Boundaries > Transparent Components/Air [1]
    2. Expand the Physics Values node and set the following properties:
      Node Property Setting
      Surface Material Specify by Part Subgroup Activated
      By Contact Subgroup
      Halogen Bulb/Air Surface Material Halogen Bulb
      Lens/Air Surface Material Lens
      Rear Housing/Air Surface Material Reflector
    3. Click Close.
  2. Specify the boundary conditions and values for the opaque components:
    1. Edit the Regions > Opaque Components > Boundaries node and set the following properties:
      Node Property Setting
      Filament
      Physics Conditions
      Thermal Specification Condition Convection
      Physics Values
      Ambient Temperature Value ${Filament_Temperature}
      Heat Transfer Coefficient Value 10000.0 W/m^2-K
      Node Property Setting
      Walls
      Physics Condition
      Thermal Specification Condition Convection
      Physics Values
      External Surface Material Surface Material Headlamp Back
      Heat Transfer Coefficient Value 20.0 W/m^2-K

      For the Walls boundary, which represents the back of the headlamp, an external surface emissivity of zero is assumed, indicating that the boundary does not contribute to external radiation.

  3. Specify the boundary conditions and values for the transparent components:
    1. Edit the Regions > Transparent Components > Boundaries > Transparent Components/Air [0] node and set the following properties:
      Node Property Setting
      Physics Values
      Surface Material Specify by Part Subgroup Activated
      By Contact Subgroup
      Halogen Bulb/Air Surface Material Halogen Bulb
      Lens/Air Surface Material Lens
    2. Edit the Regions > Transparent Components > Boundaries > Walls node and set the following properties:
      Node Property Setting
      Physics Conditions
      Thermal Specification Condition Convection
      Physics Values
      External Surface Material Specify by Part Subgroup Activated
      By Surface Subgroup
      Halogen Bulb Surface Material Halogen Bulb
      Lens Surface Material Lens
      Heat Transfer Coefficient Method By Surface Subgroup
      By Surface Subgroup
      Lens Value 20.0 W/m^2-K
      Surface Material Specify by Part Subgroup Activated
      By Surface Subgroup
      Halogen Bulb Surface Material Halogen Bulb
      Lens Surface Material Lens
  4. Edit the Interfaces > Opaque Components/Opaque Components > Physics Values node and set the following properties:
    Node Property Setting
    Contact Resistance Method By Contact Subgroup
    By Contact Subgroup
    Rear Housing/Connector Support Value 2000.0 m^2-K/W
  5. Save the simulation.