Model multi-layer shells and thermal protection system

Practice modeling multilayer shells and thermal protection system for a satellite.

Download and extract the part files.

Open the Simulation file

Open the Simulation file and reset the dialog box settings.

  1. Choose File→Open and open satellite_multilayer/communications_satellite_sim1.sim file.
  2. Choose File→Preferences→User Interface and on the Dialog and Precision page, reset the dialog box memory.
  3. In the Simulation Navigator, explore the following predefined boundary conditions:
    • A Radiation simulation object to define the radiative exchange between the satellite and the environment.
    • A Solar Heating Space simulation object to specify the solar load on the satellite.
    • Several Surface-to-Surface Contact simulation objects defined between the different bodies of the model to specify the thermal contact.

Model the thermal protection blanket of the satellite bus using a thin shell property

Modify the 2D mesh collectors of the satellite bus and specify a new thin shell property to model the thermal blanket. You will assign a new material and thermo-optical properties to the 2D mesh collectors.

  1. In the Simulation Navigator, right-click the communications_satellite_fem1.fem node and choose Make Work Part.
  2. Expand the communications_satellite_fem1.fem→2D Collectors nodes, right-click the Bus node and choose Edit.
  3. In the Material group, click Choose material .
  4. In the New Material group, click Create material .
  5. In the Name - Description box, type thermal_blanket.
  6. In the Properties group, in the Mass Density (RHO) box, type 1200 kg/m3.
  7. On the Thermal page, in the Thermal group, specify the following properties:
    • Thermal Conductivity (K) = 0.024 W/(m·K)
    • Specific Heat (CP) = 1674 J/(kg·K)
  8. Click OK twice.
  9. In the Physical Property group, from the Thin Shell Property list, select 3mm shell.
  10. In the Thermo-Optical Properties group, in the Radiation box, make sure that Top is selected to allow only the top face of the bus surface to exchange through radiation.
  11. Next to the Top list, click Open Manager .
  12. In the Create group, from the Type list, select Thermo-Optical Properties - Advanced.
  13. In the Name box, type blanket.
  14. Click Create.
  15. In the Properties group, in the Emissivity box, type 0.016.
  16. In the Absorptivity box, type 0.003.
  17. Click OK and Close.
  18. Click OK to close the Mesh Collector dialog box.

Model the solar panels using multi-layer shells non-uniform

Modify the existing 2D mesh collector of the satellite solar panels. You will create a non-uniform multi-layer shell property, containing a stack of four layers with different thermo-optical properties. You will also specify the thermal coupling between the different layers.

  1. In the Simulation Navigator, under the 2D Collectors node, right-click the Solar Panels node and choose Edit.
  2. In the Properties group, from the Type list, select Multi-Layer Shell Non-Uniform.
  3. Next to the Layer Stack Property list, click Create Physical .
  4. In the Physical Property Table group, in the Name box, type Multi-layer panels.
  5. In the Properties group, click Create Stack Layers (First Layer is Top Layer) .
  6. In the Create group, in the Name box, type Top layer, and click Create.
  7. In the Properties group, from Material list, select Aluminum_6061.
  8. In the Thickness box, type 1 mm.
  9. From the Radiation list, select Top to activate the radiation calculation for the top surface of the top layer.
  10. From the Top list, select Vapor-deposited coating - Silver.
  11. Click OK.
  12. In the Create group, in the Name box, type Middle layer_1, and click Create.
  13. In the Properties group, from Material list, select Aluminum_6061.
  14. In the Thickness box, type 20 mm.
  15. From the Radiation list, select None to deactivate the radiation calculation for the middle layer.
  16. From the Coupling Magnitude list, select Specify.
  17. In the Account for box, make sure that Conduction is selected to model conduction between the middle layer and the top layer.
  18. In the Heat Transfer Coefficient box, type 0.5 W/(m2·°C).
  19. Click OK.
  20. In the Create group, in the Name box, type Middle layer_2, and click Create.
  21. In the Properties group, from Material list, select Aluminum_6061.
  22. In the Thickness box, type 10 mm.
  23. From the Radiation list, select None to deactivate the radiation calculation for the middle layer.
  24. From the Coupling Magnitude list, select Specify.
  25. In the Account for box, make sure that Conduction is selected to model conduction between the middle layer and the top layer.
  26. In the Heat Transfer Coefficient box, type 0.5 W/(m2·°C).
  27. Click OK.
  28. In the Create group, in the Name box, type Bottom layer, and click Create.
  29. In the Properties group, from Material list, select Aluminum_6061.
  30. In the Thickness box, type 1 mm.
  31. From the Radiation list, select Bottom to activate the radiation calculation for the bottom surface of the bottom layer.
  32. From the Bottom list, select Solar Cells - COMSAT.
    This modeling object contains the thermo-optical properties of the solar cells used by the COMSAT company in communication satellites.
  33. From the Coupling Magnitude list, select Specify.
  34. In the Account for box, make sure that Conduction is selected to model conduction between the bottom layer and the middle layer.
  35. In the Heat Transfer Coefficient box, type 0.5 W/(m2·°C).
  36. Click OK.
  37. In the Selection group, select Top layer, press and hold Ctrl and select Middle layer and Bottom layer.
  38. In the List group, click Add .
    Make sure that the layers are in the following order: Top layer, Middle layer_1, Middle layer_2, Bottom layer. The solver will use this order during the solve.
  39. Click Close and OK for all dialog boxes.

Solve the model

  1. In the Simulation Navigator, right-click communications_satellite_sim1.sim node and choose Make Work Part.
  2. Right-click the Solution 1 node and choose Solve.
  3. Click OK.
  4. Wait for the solve to end, before proceeding.
  5. In the Review Results dialog box, click No.
  6. Close the Information window.
  7. In the Analysis Job Monitor dialog box, click Cancel.

Review the results

Display the temperature results and review the temperatures of the different layers of the multi-layer shell.

  1. In the Simulation Navigator, double-click the Results node.
  2. Expand the Thermal → Increment 25, 4.320E+04s, double-click the Temperature - Elemental node.
  3. Choose Results tab→Display group and from the Edge Style list, select Features .
    The Ply 1 reports the temperature results at the bottom layer of the multi-layer shell, which has the solar panels properties. Notice that the highest temperatures are on the solar panels surfaces, which face the sun.
  4. Choose Results tab→Post View group→Edit Post View .
  5. In the Result Type group, select Ply 4.
  6. Click OK.
    The Ply 4 reports the temperature results at the top layer of the multi-layer shell, which has a conductive thermal coupling with the middle layer of the multi-layer shell. The temperature is lower than the top layer because this side of the solar panels is not receiving the solar load.
  7. Choose Results tab→Post View group→Edit Post View .
  8. In the Result Type group, select Ply 3.
  9. Click OK.
    The Ply 3 reports the temperature results at the middle layer of the multi-layer shell, which has a conductive thermal coupling with the top and bottom layers.
You have completed this lab.