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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.
Miscellaneous topics
Computing coupling area for plane stress, chocking and axisymmetric elements
When a convective or radiative thermal coupling is created on plane stress or chocking elements, it is important to consider the coupling area.

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.
  - 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
    - Heat flow calculation between groups B and A using the heat flows through groups
      The heat flow between two groups is the sum of the following separate calculations: through directly connected conductances, through conductive conductances with the element CG method, and through Oppenheim radiative conductances.
    - Computing coupling area for plane stress, chocking and axisymmetric elements
      When a convective or radiative thermal coupling is created on plane stress or chocking elements, it is important to consider the coupling area.
    - Heat pipe modeling
      Heat pipes transfer heat through the length of a heat pipe, from the evaporator to the condenser, by phase changing a working fluid. The condensed fluid is pumped back to the evaporator by the capillary force in the wick structure.
    - Automatically connected streams
    - Temperature error estimates
    - Nodal temperature interpolation
      For the finite volume method, the nodal interpolation is used to obtain temperature values at the element nodes considering various physical, material, and geometrical properties.
    - Conjugate-gradient solver
      The thermal solver uses the biconjugate gradient stabilized technique in the conjugate-gradient (CG) solver to solve for temperatures using the conductance matrix until convergence.
  - 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.

Computing coupling area for plane stress, chocking and axisymmetric elements

When a convective or radiative thermal coupling is created on plane stress or chocking elements, it is important to consider the coupling area.

For plane stress elements, the computation depends on its geometrical information, such as inspecting the section of the hole surface that the specific element in this section will be used for the coupling area. For chocking elements, the coupling area corresponds to the equivalent axisymmetric area minus the gap areas.

Moreover, when coupling involves an axisymmetric edge at the junction of an axisymmetric element and a plane stress element, the coupling area is corrected as follows.

where:

R is the radius (distance to the axisymmetric axis) associated to the axisymmetric edge.
N is the number of instances of the plane stress element.
t is the thickness of the blade.

This correction removes the junction section between the plane stress and the axisymmetric elements that should not be part of the thermal coupling.