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Thermal Solver
Contains thermal solver related guides, such as the TMG reference manual, thermal API guide, and error message list.
Thermal solver theory
Describes the theory and methods of the thermal solver.
Conduction methods
To model heat conduction, the thermal solver can use two finite volume methods, center of element method or element's center of gravity method, or the finite element method.
Finite volume methods
Center of element method
The following table lists element types supported by the center of element conduction method and how the thermal solver identifies their center of location and sub-elements to create conductances between elements.
Conductance computation
Elimination of sub-elements
The thermal solver eliminates sub-elements whose centers are not selected as the center of the element, using the star-delta transformation.

Thermal Solver
Contains thermal solver related guides, such as the TMG reference manual, thermal API guide, and error message list.
- Thermal solver guides
  Maya HTT's thermal solver is included in Simcenter 3D and in Simcenter Femap. This page contains links to thermal solver guides, which help you understand how the thermal solver works.
- Thermal solver theory
  Describes the theory and methods of the thermal solver.
  - Introduction
    This guide provides the theory and methods used by the thermal solver, including methods to calculate conduction, convection, and radiation, as well as modeling specific topics using the thermal solver.
  - Conduction methods
    To model heat conduction, the thermal solver can use two finite volume methods, center of element method or element's center of gravity method, or the finite element method.
    - Finite volume methods
      - Comparison between finite volume methods
        The thermal solver supports two finite volume conduction methods—the center of element method and the element's center of gravity (CG) method—to create conductive conductances from geometry.
      - Element's center of gravity method
        The element's center of gravity (CG) method creates conductances between the CG of the element and its boundary elements.
      - Center of element method
        The following table lists element types supported by the center of element conduction method and how the thermal solver identifies their center of location and sub-elements to create conductances between elements.
        Conductance computation
        Creation of sub-element conductance
        Creation of conductance between connected sub-elements
        Sub-elements are considered connected when they share common nodes along an edge or a face.
        Elimination of sub-elements
        The thermal solver eliminates sub-elements whose centers are not selected as the center of the element, using the star-delta transformation.
      - Axisymmetric elements
        This topic describes how axisymmetric shell and solid elements are defined in thermal analysis.
      - Orthotropic materials
        This topic explains how orthotropic materials are handled in thermal analysis, detailing the process for stretching shell and solid elements based on their thermal conductivities in different material directions and the subsequent calculation of conductance.
    - Finite element method
      The finite element method computes the temperature values at discrete points, solid nodes, by solving the heat conduction equation.
  - Convective heat transfer methods
    The thermal solver computes convection conductances for various geometrical configurations using correlations that depend on specified characteristic lengths, convective surfaces, and type of convection.
  - Radiation exchange methods
    Thermal radiation is a heat transfer due to electromagnetic radiation emitted by the surface of bodies due to their temperature.
  - Miscellaneous topics
  - References
- Thermal solver API guide
  Allows you to create or add functionality to enhance the thermal solver capabilities.

Elimination of sub-elements

The thermal solver eliminates sub-elements whose centers are not selected as the center of the element, using the star-delta transformation.

The example shows that the star-delta transformation creates conductances between elements i, j and the sub-element k.

The elimination can increase the number of small value conductances that are generated between non-adjacent elements. The thermal solver eliminates insignificant conductances to reduce the number of small value conductances. A conductance, G_ij, between elements i and j is defined as insignificant when the following criteria are met:

Elements i and j do not share a common edge or boundary.
G_ij<0.001*G_i_tot
G_ji<0.001*G_j_tot

where:

G_i_tot is the sum of the conductances of element i.
G_j_tot is the sum of the conductances of element j.

For certain geometries, for example, when two obtuse or right angled triangles are joined by their longest edges, a negative or infinite conductance is computed. The conductance value is then replaced by a very large value and the two elements are merged.