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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
Creation of sub-element conductance

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 reference
  Describes the format and contents of the thermal solver's input and output files
- 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.
  - Elements in the thermal solver
    The thermal solver uses elements to calculate conductive, convective, and radiative conductances, as well as hydraulic resistances.
  - Supported element types for radiation
    Radiating elements may be defined with 1 to 4 corner nodes. The elements may be linear or parabolic.
  - 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
    Thermal radiation is a heat transfer due to electromagnetic radiation emitted by the surface of bodies due to their temperature.
  - Solar heating
  - Steady state analysis
    In a steady state analysis, the thermal solver solves the temperatures of non-sink elements iteratively using the following algorithm.
  - Transient analysis
    Transient analysis is performed using the following algorithm.
  - Hydraulic network analysis
    When the hydraulic pressure-flow network is present in the model, the thermal solver solves it at each iteration or time step using the following algorithm.
  - Miscellaneous topics
  - Thermal solver theory bibliography
    The following bibliography lists all sources used to explain how the thermal solver works.
- Thermal solver API
  Allows you to create or add functionality to enhance the thermal solver capabilities.
- Thermal solver error message list
  Lists solver messages that the thermal solver generates to communicate issues with the model or the solve.

Creation of sub-element conductance

The elemental conductance, G_i , for a sub-element i is computed as:

where:

k is the thermal conductivity.
L is the characteristic length, which is determined as follows depending on the element type:
- For a beam element, it is the distance from the element center to the ends.
- For a shell element, it is the length of the perpendicular line going from the element center to an element's edge.
- For a solid element, it is the length of the perpendicular line going from the element center to a side surface.
The thermal solver computes a negative value for L when the element center falls outside the sub-element. For example, in an obtuse triangle, the conductance between edge l_i and the element center is negative.
A is the characteristic area, which is determined as follows depending on the element type:
- For a beam element, it is the specified cross-sectional area.
- For a shell element, the area of each edge is given by the shell thickness times the edge length.
- For a solid element, it is the area of each side surface.