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SST getting started
This getting started guide provides a comprehensive introduction to thermal modeling using Simcenter 3D Space Systems Thermal (SST).
Applying boundary conditions
This topic covers boundary conditions, which define how heat is generated, transferred, and constrained within a model.

Knowledge base articles
Knowledge base articles provide concise, practical guidance for solving thermal, flow, multiphysics, space systems, and turbomachinery modeling challenges in Simcenter 3D.
SST getting started
This getting started guide provides a comprehensive introduction to thermal modeling using Simcenter 3D Space Systems Thermal (SST).
- Getting started with Space Systems Thermal
- Introducing the user interface
  This topic covers the user interface (UI) in Simcenter 3D Space Systems Thermal. You will learn how to navigate the modeling environment and how to efficiently use the available tools, menus, and commands to build, set up, and review your models.
- Simulation process
  This topic covers the typical simulation workflow used to perform thermal analyses.
- Preparing a geometry for meshing
  This topic introduces the geometry creation and preparation workflow used in Simcenter 3D Space Systems Thermal. You will learn how to create or import geometry, modify and repair it for analysis, create associative copies for CAE workflows, and idealize the geometry prior to meshing.
- Meshing a model
  This lesson introduces the core meshing workflow in Simcenter 3D Pre/Post, including element selection, mesh creation, mesh organization, and assignment of material and physical properties.
- Advanced meshing and assemblies
  This lesson covers advanced meshing techniques, including primitives-based modeling, mesh controls, mesh quality improvements, and assembly-level meshing workflows.
- Applying boundary conditions
  This topic covers boundary conditions, which define how heat is generated, transferred, and constrained within a model.
  - Define thermal boundary conditions
    Practice defining thermal boundary conditions on a drone mold. You will specify thermal simulation objects, initial conditions, and constraints.
  - Using fields to define boundary conditions
    Practice the workflow for using formula and table fields to define boundary conditions.
- Defining thermal contacts
  This lesson introduces thermal couplings and explains how conduction, convection, and radiation couplings are used to model heat transfer between unconnected or simplified regions of a model.
- Solving the model
  This lesson introduces the numerical solution techniques used by the thermal solver for steady-state and transient thermal analyses.
- Post-processing results
  This lesson introduces post-processing commands to help you review and evaluate simulation outcomes using visualization and data analysis.
- Radiation modeling methods and optical properties
  This lesson explains the two Radiation simulation object types and how each defines radiative enclosures and affects radiation calculation efficiency.
- Orbital modeling
  This lesson explains how to define orbit parameters and solar and celestial body characteristics to establish spacecraft position, orientation, and environmental conditions for space thermal analysis.
- Solar and planetary heating
  This lesson introduces solar and planetary heating, covering solar flux, atmospheric and ground effects, model orientation, and radiative heating for space and near-planet thermal analysis.
- Multilayer and thermal protection system modeling
  This lesson introduces multi-layer shell modeling to efficiently represent layered thermal structures, including thermal protection systems and insulation, using 2D meshes with through-thickness heat transfer.
- Material transformation
  This lesson introduces material transformation modeling, including phase change, ablation, charring, and thermo-optical property degradation, for simulating materials exposed to intense thermal environments.
- Articulation and motion modeling
  This lesson introduces articulation and motion modeling to capture the thermal effects of moving and rotating components, including their impact on view factors, heat loads, and radiation.
- Joule heating and thermal devices
  This lesson introduces Joule heating and thermal device modeling, covering coupled thermal–electrical simulation, electrical boundary conditions, and simplified modeling of Peltier coolers and heat pipes.
- 1D hydraulic network modeling
  This lesson introduces 1D hydraulic network modeling to simulate fluid flow, pressure losses, and convective heat transfer in duct systems using efficient one-dimensional elements.
- Mapping the results to another model
  This lesson introduces temperature result mapping between models and explains how to align source and target models for accurate data transfer.
- Customizing the thermal solver
  This lesson explains how to extend the thermal solver using user-written subroutines and plugin functions to model custom thermal behavior.
- Creating ESC models from PCB Exchange
  This lesson introduces the PCB Exchange application and explains how to import, validate, and prepare ECAD models for thermal and structural analysis.
- Electronics thermal management
  This lesson introduces electronics thermal management in space systems, focusing on heat dissipation mechanisms, cooling techniques, and thermal modeling of printed circuit boards (PCBs) and electronic components.

Applying boundary conditions

This topic covers boundary conditions, which define how heat is generated, transferred, and constrained within a model.

This lesson may include hands-on exercises. Review the Discussion section for background information or click the button to proceed to the practical section.

Discussion

Boundary conditions and related modeling entities are organized as loads, constraints, simulation objects, and modeling objects, and are managed primarily through the Simulation Navigator. Boundary conditions are automatically associated with the active solution, and deleting a boundary condition removes all its instances from the model.

Thermal loads

Represent different forms of heat generation applied to the model. Load magnitude can be defined as a constant value or as a function of time, temperature, fields, or expressions. You can control thermal load behavior using:

Reference Temperature Set modeling objects, which use selected entities to evaluate temperature-dependent load magnitudes.
Thermostat modeling objects, which activate or deactivate loads based on sensor temperatures.
Active Heater Controller modeling objects, which provide logic-based control using proportional or PID behavior.

For temperature-based control, the software can evaluate average, minimum, or maximum temperatures over selected elements.

Temperature constraints

Specify fixed heat source or sink temperatures in the model. These constraints define known temperature conditions that influence heat transfer and system response.

Convection to environment

Models natural or forced convection when convection coefficients or related parameters are known.

Free convection uses standard correlations based on geometry type, such as plates, cylinders, or spheres.
Forced convection models heat transfer using defined fluid velocity and temperature.

The software calculates a single global heat transfer coefficient for the selected surfaces and adjusts correlations based on gravity assumptions.

Hands-on material

To gain experience with the topics discussed here, complete the following:

Further learning