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.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. 
 - Click