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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.
Heat flux calculation in radiative heat transfer
The thermal solver computes the incident, reflected, absorbed, and transmitted energy fluxes for radiative heat transfer analysis.

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.
  - 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 using deterministic ray-tracing
    - View factors calculation using the hemicube method
      The thermal solver uses the hemicube method to compute diffuse blackbody view factors.
    - Radiation enclosures
      The thermal solver separates elements into enclosures. An enclosure is defined to be a set of elements that view each other and only each other.
    - Diffuse reflectivity calculation
      This section describes the calculation of diffuse reflectivity for materials with angle-dependent specular reflectivity or transmissivity.
    - Effective property calculation
      For each element, the thermal solver calculates the effective properties from the surface properties and self-view factors.
    - Heat flux calculation in radiative heat transfer
      The thermal solver computes the incident, reflected, absorbed, and transmitted energy fluxes for radiative heat transfer analysis.
    - Plane stress view factor calculation when modeling with axisymmetric 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.
  - 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.

Heat flux calculation in radiative heat transfer

The thermal solver computes the incident, reflected, absorbed, and transmitted energy fluxes for radiative heat transfer analysis.

Total incident heat flux

Radiated heat flux tracked through the system for ray-traced heat flux view factors.

Radiated heat flux tracked through the system for non-ray-traced heat flux view factors.

Heat flux absorbed by the element ifor non-ray-traced heat flux view factors.

The total incident diffuse flux on element i of the heat flux view factor V_i.

Heat flux reflected specularly for ray-traced heat flux view factors.

Heat flux reflected specularly for non-ray-traced heat flux view factors.

Heat flux transmitted through a material for ray-traced heat flux view factors.

Heat flux transmitted through a material for non-ray-traced heat flux view factors.

In these equations:

V_i is the heat flux view factor, albedo factor, Earth view factor, or heat flux view factor to the element.
A_i is the area of the element. If VFMERGE option is used, this is the merged area of the element.
τ_i is the transparency of element i.
ρ_si is the average specular reflectivity, calculated by averaging the data in the array.
PS is the emitted power per unit area of the source element. PS is the collimated solar spectrum radiative source's (sun's) power output per unit area arriving at the element for solar or albedo calculations, and the heat load per unit area leaving the surface of the Earth for IR spectrum calculations. PS=1 for heat flux view factor calculations because V_i already includes the source element’s emitted power per unit area.