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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.
View factor calculation without ray-tracing
Albedo factors calculation without ray-tracing

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 calculation without ray-tracing
      - View factor calculation algorithm
        The following outlines the steps by which view factors are calculated without ray-tracing using deterministic method without explicit sky modeling.
      - View factor accuracy considerations
        The accuracy of the Nusselt sphere technique is compared with the contour integral technique and the double summation technique.
      - Inaccuracies due to non-uniform illumination
        Radiation calculations with view factors assume uniform illumination over an element, and potentially significant errors may be introduced when this assumption is not fulfilled.
      - Planet view factor calculation without ray-tracing
        The planet view factor is the element's view factor to the planet.
      - Albedo factors 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.

Albedo factors calculation without ray-tracing

The albedo view factor is defined by:

where:

ALB is the albedo value.
ALB_i is the albedo view factor of element i to the planet.
θ_sun is the angle between the local planet's surface normal and the sun vector.
dVF_iPlanet is the incremental view factor from element i to the planet.

An albedo blockage factor for element i, ABF_i, is calculated similarly to the planet blockage factor, except that each DEVF_i is multiplied by the solar illumination weighting factor.

where SIWF_k is the solar illumination weighting factor, equal to the solar view factor of the k^th planet sub-element.

The albedo blockage factor equal one if element i does not see any part of the planet which reflects the sun.

The unshadowed albedo view factor is calculated by interpolating the tables, using the sun angle, planet angle, and albedo value: