Airfoil (NACA 0012) - CFD Simulation SimFlow Tutorial

Airfoil NACA 0012 tutorial presents the analysis of the airfoil profile. Using an additional feature dedicated to 2D airfoil meshing and analysis you will be able to perform such a simulation in the shortest way.

SimFlow is a general purpose CFD Software

To follow this tutorial, you will need SimFlow free version, you may download it via the following link:
Download SimFlow

We need to enable the Airfoil feature in the SimFlow launcher in the Advanced Settings section.

Open SimFlow and create a new case named airfoil_naca_0012

Firstly we need to Download GeometryNaca0012

After creating a mesh, it will appear in the 3D window.

Now we will check if the boundaries are set properly.

We want to analyze incompressible turbulent flow around the Airfoil. For this purpose, we will use the SIMPLE (simpleFoam) solver.

We are going to use the standard \(k-\omega \; SST\) model to handle turbulence. This model gives very good agreement with experimental data and is commonly used for aerodynamics applications.

The calculations will be run until Residuals will drop down under 10 ⁻⁶ . This criterion will guarantee high accuracy and will require more iteration. To make sure that the fluid solver will be able to capture very small changes in the flow, we need to make sure that the linear solvers for fluid flow equations will also be able to operate on very slight flow changes. To do this, we will change default solver tolerances.

It is handy to parameterize velocity value to be easily accessible in the further setup. To be able to compare the results with test results we should assume \(Re=6000000\). Based on the air viscosity \(\nu = 1.5 \cdot 10^{-5} \; m^2/s \) and chord \(c\approx 1 \;m\) we calculate the velocity from the equation: \(V=Re \cdot \frac{\nu}{c}\)

We will use the "Potential" initialization feature. This utility solves pseudo potential flow prior to actual calculations. This will give a better initial guess for velocity and pressure fields.

\(U_\infty\) \({\sf [m/s]}\)U

Additionally to observing force coefficients, we will display intermediate results on a section plane.

This controls when results are written to the hard drive. When slices are enabled this also applies to them. Each new result will be displayed at a specified interval.

To speed up the calculation process increase the number of CPUs basing on your PC capability. The free version allows you to use only 2 processors in parallel mode. To get the full version, you can use the contact form to Request 30-day Trial

Estimated computation time for 2 processors: 15 minutes

If you want to change the angle of the attack, you should first reset the simulation in the run panel.

In the Airfoil panel, we can now remesh the Airfoil change angle of attack. And then rerun the simulation.

After creating a mesh, it will appear in the 3D window.

You might repeat the above operations for different angles of attack, e.g: 5, 10 and 15 degrees. Next comparing them with the experimental data (NASA Langley, 1988) you should be able to obtain the following results.

This concludes the tutorial, covering all the aspects we intended to showcase. To create a finely tuned presentation of the results, you may take advantage of the seamless integration with ParaView. You can easily open simulation results in ParaView with a single click from SimFlow.

In ParaView, you can perform typical and advanced postprocessing tasks such as displaying streamlines, contour plots, vector fields, line or time plots, and calculating volume or surface integrals.

To familiarize yourself with the ParaView capabilities, it’s worth checking out our video tutorial, Paraview CFD Tutorial - Advanced Postprocessing in ParaView, in which we demonstrate some of the most commonly used post-processing techniques.

Paraview CFD Tutorial - Advanced Postprocessing in ParaView