Tutorial: Hex-Dominant Automated – Internal Flow Through an Angled Pipe

This short tutorial shows how to create a mesh using the automated Hex-dominant operation for internal flow analysis.
Import tutorial project into workbench.
You can also take a look at the respective public project.

Create a New Simulation

  • As a first step, we need to create a new simulation. To create a simulation, left-click on the ‘Pipe-shape’ and then on the ‘Create Simulation’.
create simulation for an angled pipe on simscale platform
Creating a simulation for the pipe geometry.

This dialog box allows the user to select the simulation model. Click on the ‘Incompressibleoption and then on the ‘Create Simulation’ one.

create a new incompressible fluid flow new simulation with simscale
Choosing the incompressible analysis for the pipe simulation.

The default settings for the simulation are kept the same. Save the simulation model by clicking on the tick mark.

incompressible fluid flow turbulence model steady-state
Setting the properties of the simulation.

Mesh Properties

Hex-Dominant Automated

  •  Left-click on the ‘Mesh’ icon to create a new mesh.
  • Choose the ‘Hex-Dominant (only CFD)’ Algorithm and the meshing mode to be ‘Internal‘.
  • Select the sizing option to ‘Automatic mesh sizing‘ and change the desired mesh sizing to ‘Fine‘.
  • Specify the ‘Number of processors’ for the meshing operation (16 in this tutorial).
Mesh panel hex-dominant internal meshing mode automatic mesh sizing fine automatic boundary layers SimScale Workbench angled pipe
Setting the Hex-dominant properties for an automated mesh generation.

Boundary Layer Refinement

  • In order to correctly model the flow through a pipe, the boundary layer has to be resolved accurately. This can be achieved by refining the mesh in the regions close to the walls.
  • The best method to do this is with the help of a layer inflation mesh refinement. To add a mesh refinement, click on the ‘+’ icon next to ‘Refinements‘ under the ‘Mesh.
  • Select the  ‘Inflate boundary layer’ setting.
add refinement simscale mesh inflate boundary layer angled pipe hex dominant automatic
Addition of an inflate boundary layer refinement.
  • Keep the default settings in the dialog box.
add refinement mesh inflate boundary layer angled pipe layers expansion ratio minimum thickness first layer
Inflate boundary layer refinement properties.
  • The next step is to pick the faces.
  • All faces except the inlet and outlet faces need to be selected.
  • Select all of the faces of the pipe by dragging the Active box selection over the pipe and deselect the inlet and outlet faces by clicking on them.
active box selection mesh faces assignment inflate boundary layer angled pipe mesh
Selecting only the walls of the tube for the inflate boundary layer refinement.

It would be seen 5 faces are selected for boundary layer refinement.

Mesh Generation & Results

Meshing Operation

The automatic mesh generation is performed as part of the simulation run. After all the properties and boundary conditions of the simulation are added, a new run gets started.

start a new simulation run simscale
Starting a new simulation run.

Right before the simulation begins, the mesh is being created, as it is indicated at the bottom left of the interface with the blue icon. The progress can be monitored from the blue bar of the mesh panel.

computing mesh bar for simscale angled pipe hex dominant mesh
Monitoring the progress of the mesh generation.

Mesh Inspection & Mesh Clip Generation

The mesh is generated when the bottom left icon next to the mesh name turns to a green circle with a check mark.
The event log can be checked for further information on the mesh.

meshing log workbench hex dominant angled pipe
By reading the event log, the meshing procedure can be examined.

The boundary layer generation can easily be seen by zooming in on the mesh inlet.

mesh details hex dominant final mesh angled pipe
Details of the final mesh.

Click on the ‘Mesh clip‘ to inspect the internal mesh. Adjust the settings of the normal. Click on the ‘Generate Mesh Clip‘ icon.

generate mesh clip settings normal to axis hex dominant angled pipe mesh results
Adding a cutting plane to inspect the internal mesh of the pipe.

The mesh clip generated is presented below:

cutting plane mesh clip settings normal to axis hex dominant angled pipe mesh results
The internal mesh of the pipe, viewed from a cutting plane normal to the Y-axis.

If you are wondering how to post process your results have a look at this guideline.

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