Surface heat transfer

Heat transfer at the face of an element can be prescribed in the first load case, with the identifier T 1 through T 13, or in any subsequent load case, with the identifier T 11 through T 13. In the first case, the prescription applies to the entire process under consideration; in the other cases, only to the load case in which it was declared.

In the name.iB file, a vector is first defined using a SV set:

SV set number T 1/11 V $\alpha$ $T_o$ ; $\dot q=\alpha\left(T-T_o\right)$

or

SV set number T 2/12 V $c$ $T_o$ ; $\dot q=c\left(T^4-T_o^4\right)$

or

SV set number T 3/13 V $c_1$ $c_2$ $c_3$ $T_o$ ; $\dot q=c_1\left(T^{c_2}-T_o^{c_2}\right)^{c_3}$

and the set thus defined is then assigned to the face of the selected elements:

AS load case number /$\dots$ /S set number E element number list S face number /$\dots$

where

  • $T_o~[^\circ\text{C}]$ is the ambient temperature,
  • $\alpha~[\text{W}/\text{m}^2\text{K}]$ is the convective heat transfer coefficient,
  • $c~[\text{W}/\text{m}^2\text{K}^4]$ is the radiation constant,
  • $c_1~[\text{W}/\text{m}^2\text{K}^{c_2+c_3}]$ and $c_2,c_3~[1]$ are the constants of the general heat transfer law.
Note
Faces and their local numbers are defined for isoparametric elements and semi-loof elements, see the Reference Manual. For 2D isoparametric elements, the edge of the element is considered its face, since it has a nonzero thickness (and therefore also an area). For heat transfer computations, a semi-loof element has two faces defined.
Note
The components of the vector can depend on the global coordinates $x,y,z$, using any of the available functional dependencies, see the Reference Manual.