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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.
Radiation exchange methods
Thermal radiation is a heat transfer due to electromagnetic radiation emitted by the surface of bodies due to their temperature.
Basic view factor concepts
View factor sum

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.
  - 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.
    - Basic view factor concepts
      - View factor classifications
        Thermal solver view factors have three main classifications: view factors, orbital view factors, and heat flux view factors.
      - Understanding view factors
      - View factor sum
      - Orbital view factors
      - Supported element types
        Radiating elements may be defined with 1 to 4 corner nodes. The elements may be linear or parabolic.
      - Shadowing surfaces
      - Elemental subdivision algorithm
        For certain operations such as shadowing checks and ray-tracing elements need to be subdivided into sub-elements.
    - View factor calculation without ray-tracing
    - View factor calculation using ray-tracing
    - Plane stress view factor calculation when modeling with axisymetric or 3D elements
      This section explains how the thermal solver computes the view factor for axisymmetric or mixed 2D axi-3D models with plane stress elements for radiation requests.
  - Miscellaneous topics
  - References
- Thermal solver API guide
  Allows you to create or add functionality to enhance the thermal solver capabilities.

View factor sum

The theoretical view factor sum for an element is 1. However, because of model geometry imperfections and approximations made during shadowing calculations, this condition is not always fulfilled.

where:

n is the total number of surfaces within the enclosure.
VF_ij is the view factor from surface i to surface j.

The residual view factor is an indication of the accuracy of the view factor calculations:

Residual view factor = 1 – view factor sum

Residual view factors between -0.05 to 0.05 are usually acceptable.

Generally, view factor calculation accuracy can be increased by specifying higher elemental subdivision for the deterministic method or by increasing the number of rays for Monte Carlo method.