# Thermal Option

The thermal option in 3DEC allows the simulation of transient heat conduction. There are two
separate formulations of the thermal logic. The first is a numerical formulation using the explicit
or implicit finite difference method. This method is more accurate for short times, and includes
thermal-mechanical fluid coupling. The second is an analytical formulation that uses superposition
of point heat sources in an infinite medium. This method is suitable for long thermal times and is
very fast. The comparative features of the two methods are listed below.

Table 1: Comparison of Features Available with Numerical vs Analytical Formulations
feature |
numerical |
analytical |

thermal mechanical coupling |
yes |
yes |

thermal fluid coupling |
yes |
no |

thermal convection in fluid |
yes |
no |

temperature boundary |
yes |
no |

thermal flux boundary |
yes |
no |

thermal convection boundary |
yes |
no |

adiabatic boundary |
yes |
yes |

nonhomogeneous thermal block properties |
yes |
no |

heat sources |
yes |
yes |