Define External Radiation
Use the External tool to apply external radiation heat transfer to selected surfaces or thin solids.
- 
                From the Radiation ribbon, click the
                            External tool.
                 
 Figure 1.
- 
                Select the surfaces or thin solids on which to apply the radiation heat
                    transfer.
                To Select Do This Surfaces - Set the guide bar selector to Surfaces.
- Select surfaces.
 Thin Solids - Change the guide bar selector to Thin Solids.
- Select thin solids.Note: You can only select thin solids if layers have been defined using the Thin tool.
- Select a direction option from the
                                guide bar.- Direction: Away from Parent Surface - Define the condition on the boundary surface furthest from the parent surface.
- Direction: Adjacent to Parent Surface - Define the condition on the boundary surface closest to the parent surface.
- Direction: Both Sides - Define the condition on both sides of the boundary surface.
 
 An external radiation dialog opens.
- 
                Select an external radiation definition from the drop-down menu and define
                    radiation properties.
                Option Description Zero Enter a reference temperature value. Constant Enter a reference temperature and flux value. Piecewise Linear and Cubic Spline Enter a reference temperature value, define the x-axis using the Curve fit variable drop-down menu, then use the table and the plot area to define the radiation. 
- 
                From the guide bar, execute the command in the following
                    ways:
                - Click  to confirm your selection and remain in the
                            tool. to confirm your selection and remain in the
                            tool.This allows you to continue creating instances and helps you visualize and edit instances with the legend. 
- Click  to confirm your selection and exit the
                        tool. to confirm your selection and exit the
                        tool.
 
- Click