# Tutorial: Compressible flow over airfoil

This tutorial leads you through the external aerodynamic simulation of an airfoil.

Import tutorial case into workbench

## Step-by-step

### Import tutorial project

• To start this tutorial import the tutorial project into your ‘Dashboard’ via the link above.
• For convenience the mesh has already been created and would be loaded into the viewer as shown below
• You can interact with the mesh as in a normal desktop application

### Create a simulation

• To create a new simulation click on the ‘+’ option next to the ‘Simulations’ tab
• Select the Compressible Flow Analysis type and click ‘Ok’
• 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 parts that are completed are highlighted with a green check. Parts 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
• Set the turbulence model to laminar and choose transient as shown below
• Next, in the tree in the navigator pane, select Domain and assign the uploaded mesh and ‘save’

### Material selection and assignment

• 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 “Air” and click on ‘Ok’. This will then automatically load the standard properties for air.
• Then, select the volume domain and save.

### Initial conditions

• In the tree, select Initial Conditions
• Apply the initial conditions according to the following table:
Variable Value Unit
pressure 1e5 Pa
velocity (x, y, z) (30, 0, 0) ms

$\frac{m}{s}$

temperature 293 K
Turbulent dynamic viscosity 0 kgsm

$\frac{kg}{sm}$

### Boundary conditions

Now, we come to define the boundary conditions.

• To create a boundary condition, click on the ‘+’ option next to the Boundary conditions and select the required boundary condition from drop down menu, as shown in figure.
• For the Inlet select the ‘Velocity Inlet’ boundary condition, specify the values shown in the figure below, assign inlet faces for this boundary condition and click on save.
• Add other boundary conditions as shown in figures below
• Pressure Outlet
• Symmetry
• 2D Empty
• Wall

### Numerics

• Setup the Properties as shown in figure. Keep the Solver settings as default.
• Keep the Schemes to default values as shown.

### Simulation Control

• We will run the simulation on 8 cores, with a timestep length of 0.00005 s and End time value of 0.07 s.
• Set ‘Write control’ to time step with value of 200 for the results to be written.

### 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

### Post processing

• After the run has been finished, you will see the convergence plots.
• 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)
• Select the results and click “All Velocity[node]” to visualize Velocity Profile.