Thermal rod elements are two-node members allowed arbitrary orientation in the XYZ system. These elements are used to model heat transfer in long, thin structures.
Two material models are available to describe the thermal characteristic of the structure: isotropic and temperature dependent isotropic. These models require the density and thermal data for the material.
Rod elements can have convective and radiative load specified on their surface. Heat fluxes can also be directly specified on their surfaces. These surfaces are calculated using the length of elements and the perimeter. Rod elements can also incur heat generation per unit volume. The volume of rod elements is calculated using their length and area.
When using rod elements, you must specify the Cross-sectional area and Perimeter of cross-section in the General tab of the Element Definition dialog. The cross-sectional area will be used to calculate the heat flow through the rod elements. The perimeter of cross-section will be used to calculate the surface area for convection radiation and heat flux loads.
You must also specify which material model will be used in the Material Model drop-down box. The Isotropic option will use identical material properties in the entire model regardless of direction. The Temperature Dependent Isotropic option will use different material properties depending on the temperature of the rod elements. The properties will not vary with direction.