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Space Systems Thermal
Contains Spase Systems Thermal knowledge base articles, including how-to-guides, best practices, and troubleshooting tips.
How to control satellite boundary conditions during eclipse
This article explains how to control loads on satellite panels during eclipse periods without using complex time-dependent fields.

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  Contains Spase Systems Thermal knowledge base articles, including how-to-guides, best practices, and troubleshooting tips.
  - Multi-layer insulation modeling in Simcenter 3D Thermal
    This article shows how to model multi-layer insulation in different ways. Multi-layer insulation (MLI) is a type of thermal insulation commonly used in spacecraft and other applications where it is necessary to maintain a stable temperature within a structure.
  - Modeling charring ablative materials
    This article describes how to simulate the material transformation that an object undergoes when it is exposed to an intense transient heat source.
  - Model checks in Space Systems Thermal
    This article outlines methods to verify that a model functions as expected, covering fundamental Space Systems Thermal model checks.
  - How to extract solar loads in the thermal analysis without calculating temperatures?
    This article outlines two methods of extracting solar loads, including Solar, Albedo, and IR.
  - How to improve the solution time for models with solar heating and radiation request?
    This article provides guidelines on speeding up solutions that include solar heating and radiation requests.
  - How to control satellite boundary conditions during eclipse
    This article explains how to control loads on satellite panels during eclipse periods without using complex time-dependent fields.
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  Contains multiphysics knowledge base articles, including how-to-guides, best practices, and troubleshooting tips.
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How to control satellite boundary conditions during eclipse

This article explains how to control loads on satellite panels during eclipse periods without using complex time-dependent fields.

Details

When simulating satellite thermal behavior, boundary conditions often need to change depending on whether the spacecraft is in sunlight or eclipse. Usually, this requires creating multiple time-dependent fields, which can be complex and time-consuming.

Using the DURINGECLIPSE() function, you can simplify this process by directly switching loads or boundary conditions based on eclipse periods. This function returns true when the solver time is within an eclipse and false otherwise.

For example, to apply 100 W on a panel during eclipse, and 0W in sunlight, you can use DURINGECLIPSE() as an expression in the Thermal Loads dialog box as shown in the following image.

Thermal Loads dialog box showing the eclipse-dependent expression.

From the results, the total panel heat load shows the effect of eclipse switching:

The eclipse starts at 3065.88 s and ends at 5161.22 s.
The heat load is 100 W during this period, and 0 W otherwise.

Time history plot showing a plateau at 100 W during the eclipse.