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Tutorial: Hex-dominant parametric – Electronics cooling

Overview:

In this tutorial, the meshing process for a geometry used for cooling electronic device using the conjugate heat transfer (CHT) technique is carried out using the “Hex-dominant parametric” approach. The “Hex-dominant parametric (only CFD)” is the semi-automatic meshing option that uses hexahedral cells and allows full flexibility in meshing parameters with all type of refinements options. The objective is to get a good quality mesh that resolves the geometry and domain well.

This tutorial will highlight some essential points of the meshing process that would help in getting better simulation results.

Link to tutorial project containing the geometry:

Import tutorial project into workbench

  • As a first step we need to create a new simulation. To create a simulation left click under the Geometries  and then on Create Simulation.

Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials

    Create Simulation for Conjugate Heat Transfer
  • Select the simulation model. Click on Conjugate Heat Transfer.

    Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
    Conjugate Heat Transfer Analysis for Electronic Heat Sink
  • In this case of electronic cooling sink the uploaded geometry has three solids, two representing the FB-4 chips and one for heat sink, and one fluid region which represents the air domain.

Mesh Generation

  •  Left click on the mesh icon to create a new mesh.
  • Choose the Hex-Dominant parametric (only CFD) Algorithm.
  • Select the number of cells in each direction for Bounding Box as shown in the figure below.

    Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
    Mesh Settings – Bounding Box Resolution
  • Scroll down to specify the Number of computing cores for the meshing operation (16 in this tutorial)

    Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
    Selecting the number of processors for meshing

Geometry Primitives (Base Mesh Box and Material Point)

Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
Set up the coordinates of the background mesh box

We start with Background Mesh Box, under Geometry Primitives. Here we specify the extents of the box for the Base Mesh. It is suggested to maintain the automatic bounding box generated when a geometry is imported, since this is an important factor to split the different faces. Hence the following Background Mesh Box and Material Point settings can be left default for any other simulations you want to perform using conjugate heat transfer problem.

  • Keep the default values for material point coordinates
Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
Set up the coordinates of the material point

Mesh Refinements

  • In order to have a finer mesh over the surface of the body, we add surface refinement.
  • Click on Refinements to add a new refinement and select surface refinement. We use 2 surface refinements:

Fluid Region Surface Refinement

  • Click on Refinements to add a new refinement and select surface refinement.
  • Rename it to ‘Fluid Surface Refinement’
  • Specify the parameters as shown in figure below. The fluid domain has to be selected for this surface refinement.

    Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
    Surface refinement of fluid regions

Solid Region Surface Refinement

  • Click on Refinements to add a new refinement and select surface refinement.
  • Rename it to ‘Solid Region Refinement’
  • Specify the parameters as shown in figure below. The remaining 3 solids have to be selected for the surface refinement.

    Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
    Surface refinement for solid regions
  • Once the mesh is fully set up, the mesh generation can be started.

Mesh Inspection

  • The generated mesh is displayed below:

    Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
    Mesh generated for electronic heat sink
  • Click on generate mesh clip to inspect the internal mesh. Adjust the settings of the normal. Click on generate mesh clip icon.

    Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
    Generation of mesh clip for mesh inspection
  • The mesh of the heat sink is shown below

    Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
    Surface refinement over the heat sink
  • The meshes of both the chips are presented below
Meshing, CFD, Simscale, Internal Flow Analsysis, Electronic Cooling, Meshing Tutorials
Surface refinement over chips
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