Documentation

Heat transfer within a heat-sink

This tutorial shows how to analyze the Heat transfer in a heat sink.

Import tutorial case into workbench

Step-by-Step

 Import tutorial project

  • To start this tutorial, you have to import the tutorial project into your ‘Dashboard’ via the link above.

The CAD model

  • Once the ‘Work bench’ is open you will be in the ‘Geometries’ tab.
  • The CAD model named “heat-sink” would be displayed in the viewer
  • You can interact with the CAD model as in a normal desktop application
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Heat sink CAD geometry

Create a Simulation

  • To create a new simulation click on the ‘+’ option next to the ‘Simulations’ tab
  • In this tutorial we want to calculate the heat flux and the temperature distribution in the heat sink due to the convective boundary conditions caused by the surrounding flows. Hence we choose Heat transfer Analysis type.
  • After clicking ‘OK’, a new tree will be automatically generated in the left panel with all the parameters and settings that are necessary to completely specify such an analysis.
  • All sections that are completed are highlighted with a green check. Sections that need to be specified have a red circle. While, the blue circle indicates an optional settings that does not need to be filled out
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Creating a simulation
  • As the time-invariant state should be calculated we select Steady-state under Properties.
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Simulation properties

 Create a mesh

  • Select the mesh option and set the parameters as shown in figure below
  • The Tet-dominant mesh algorithm is used by default as this is a FEA application
  • Set the fineness of the mesh to ‘Coarse’
  • Click on the Generate button to start the mesh generation operation
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Creating the mesh
  • As soon as the mesh is finished it is loaded into the viewer (as shown below) and you can interact with it in the same way as with the geometry before.
  • Use the meshing log to get some general information about the mesh e.g. number of nodes and elements in the mesh.
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Generated Mesh

Adding materials to the domain

  • Next, add the materials from the ‘Material Library’ for fluid and the solid phases. First, we start with clicking on sub-tree “Materials”, click on ‘+’ from the options panel as shown.
  • This pops-up a ‘Material Library’ from which we select “Steel” and click on ‘Ok’. This will then automatically load the standard properties for Steel.
  • Then, select the volume domain and save
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Adding a new material
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Material properties and assignment to the heat sink

Boundary conditions

  • Use the Boundary conditions section in order to apply heat flux or temperature boundary conditions. A new boundary condition can be added by clicking on the ‘+’ button next to the ‘Boundary Conditions’ option.
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Adding a new boundary condition
  • We use a simple boundary condition setup: The heat source is set to be the single face on the bottom of the face where we apply a fixed temperature of 70 degrees Celsius or 343.15 Kelvin.
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Boundary condition 1: Fixed temperature
  • The second boundary condition is the convective heat flux taking place on all other faces.
  • so select the bottom heat source face and then invert selection by using the right click and selecting the ‘Invert selection’ option .
  • set the boundary condition as shown in figure below.
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Using the Invert selection
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Boundary condition 2: Convective heat flux
  • Use the default Numerics as shown in figure below
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Numerics
  • If you followed the settings of this tutorial so far especially considering the mesh fineness it is possible to select one computing core for the calculation in the Simulation Control section. For finer meshes it may be necessary to choose a larger instance in order to provide memory and reduce calculation time.

 Start a simulation run

  • The last thing to do for running this simulation is to create a run.
  • The new run is created by clicking on the ‘+’ symbol next to ‘Simulation Runs’
  • Give a name to the run and start the run
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Starting a new simulation run

Post-Processing

  • Once the simulation is finished, select the ‘Solution fields’ under the Run to post process the results on the platform. Or they can be downloaded and post-processed locally (e.g. with ParaView)
  • Use the integrated post-processing environment for visualizing the results as below
  • Select  results and click “Temperature[node]” to visualize Temperature Profile
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Temperature distribution around the heat sink
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Temperature distribution around the heat sink

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