Introducing boundary conditions
This topic explains the different types of boundary conditions used in turbomachinery simulations and how thermal, shared, and structural conditions are applied through simulation objects, constraints, and loads to represent multiphysics behavior.
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
Turbomachinery simulations rely on multiple interacting physical phenomena, each represented through specific boundary conditions.
- Convection boundary conditions capture heat transfer between fluids and solid components across main gas paths, cooling streams, cavities, and external flows.
- Contact boundary conditions model thermal and mechanical interactions at interfaces such as joints, bolts, flanges, and mating surfaces.
- Radiation boundary conditions account for radiative heat transfer from hot gas paths to surrounding components.
- Structural boundary conditions represent loads, constraints, rotational effects, and deformation-driven behavior within the engine.
| Boundary condition categories | Thermal boundary conditions | Shared boundary conditions | Structural boundary conditions |
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| Simulation objects |
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| Constraints |
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| Loads |
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Hands-on material
To gain experience with the topics discussed here, complete the following:
Perform a heat transfer analysis between a chip, PCB, and casing
Model thermal connections of bolts, nuts, holes, and flanges
Define convection boundary conditions at 2D interfaces
Define convection boundary conditions using ducts
Define convection boundary conditions using thermal streams and voids
Using fields to define boundary conditions
Learn thermal plugin basics
Explore advanced thermo-optical properties for radiation modeling
Set up radiation requests
Model radiation on 3D components
Further learning
How to use an average surface temperature as an input in expressions?
How to define a value in the boundary condition as a function of time?
How to constrain duct temperatures on nodes or elements in Simcenter 3D?
How to apply a spatially varying heat load on a polygon face?
How to create a thermal coupling between 2D and 0D elements?
How to create a thermal coupling between 2D and 3D geometry?
How to verify if thermal couplings are correctly defined?
How to check connections in thermal coupling?
