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July 2019


Luma Bendini

Computational Fluid Dynamics explained

Understand the main concepts behind one of the most complex computer-aided engineering technologies.


What is a CFD Simulation?

Can you picture the difference between these two images?

Can you see the air flowing around the flying bus?

On the left is a video game snapshot. It is generated through a visual effect software used for films, video games and animations. You can see the air pushing the balloon and it looks pretty realistic. But in reality, the picture on the right is the one that most represents how air flows around the balloon in this particular scenario.

The image on the right is generated by numerical simulation software.

What you see in the picture on the right is actually the visual aid for a lot of numbers or algorithms working on  supercomputers to try to solve one of the most complex equations ever discovered- the one that describes turbulent fluid flow. This is a Computational Fluid Dynamic simulation.

The goal of a CFD simulation is to predict the behaviour of flow, like water or air, as it would happen in the real world using high-performance computing. Behind the scenes of a CFD image, there’s a lot of mathematics, physics and computer science going on.

Meshing, solving and post-processing

Meshing, solving and post-processing

In general, we can say simulations run in 3 different steps. These processes can be really complex and require a lot of expertise. But, even if you’re not a specialist, you can still benefit from CFD technology by choosing an automated solution that will require less manual work to generate accurate results!


3 steps of a CFD simulation:

1. First the creation of a mesh that will define the domain of interest.

2. Secondly, the actual numerical simulation that will calculate the flow on that defined domain.

3. And lastly, the creation of images and movies to see and analyse the simulation.