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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).
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.

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.
- 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.
  - Create a 1D duct network in a mold
    Practice creating immersed ducts in a mold. You will create a 1D collector and display the ducts in the model.
  - Create duct boundary conditions in a thermal model
    Practice defining duct boundary conditions in a thermal model. You will specify immersed ducts boundaries and solve a transient solution, using a mold cooling model.
- 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.

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.

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

1D hydraulic network modeling is used to simulate fluid flow and convective heat transfer in duct systems without the computational cost of full CFD analysis. In Simcenter 3D Space Systems Thermal, hydraulic elements represent one-dimensional duct networks and allow you to model pressure losses, mass flow, and heat exchange between the fluid and surrounding structures.

Duct flow networks define advective heat transfer due to fluid mass flow and include properties such as cross-sectional area, hydraulic diameter, flow resistance, and fluid conduction. These networks can be used to model steady-state or transient fluid behavior and are well suited for applications such as cooling channels, ventilation systems, and internal fluid loops.

Depending on the level of detail required, duct networks can be created using different approaches. You can solve for pressure, velocity, mass flow, and temperature using standard 1D duct elements, prescribe fixed mass flows using duct elements with mass flow conditions, or include heat transfer through duct walls using thick-wall duct elements. Heat exchange between ducts and surrounding 3D structures can also be modeled directly in the solution using the Immersed Ducts simulation objects.

The thermal solver treats duct flow in a manner analogous to heat transfer, conserving mass flow and using correlations for laminar, developing, and turbulent forced convection. Head losses at bends and junctions are automatically computed based on duct geometry. When required, additional thermal elements are created to represent duct walls and enable accurate coupling between the fluid and the solid model.

These capabilities allow efficient simulation of fluid-driven thermal behavior in complex systems while maintaining a balance between accuracy and computational performance.

Hands-on material

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