*CCNV
When enabled, this card will automatically apply predetermined convection coefficients to the external surfaces of the modeled component, based upon the thermal conductivity of the material. The function used has been constructed comparing convection and powder boundary conditions, the values of which are plotted in Figure 1. Using this card should yield a thermal history close to that calculated when using powder elements with *+PDR, but without the computational overhead of meshing the powder and modeling thermal losses into it directly. The convection, which is value calculated and applied to the model, is recorded in the thermal log file.
Figure 1: Automatically calculated heat loss coefficients based on thermal conductivity