Moving ground in car aerodynamics simulation

[kajetankurtek]

Hi everyone,

I'm working on a CFD simulation of airflow around a car model, and I need to include moving ground to better replicate real-world conditions. However, I haven't found a clear way to implement it in my simulation. What is best way to do this? I used Fusion 360 to create the model and Autodesk CFD 2024 for the simulation.

Any guidance or references would be greatly appreciated. Thanks!

[John_Holtz]

Hi @kajetankurtek . Welcome to the CFD forum.

I assume your model is with the car stationary and the air has a velocity at the inlet (like in a wind tunnel). To duplicate a car moving relative to the ground, you also want to have the ground moving relative to the car.

I suggest you apply a velocity boundary condition to the ground. The air at the ground is moving at the same speed as the car but in the opposite direction.  The velocity perpendicular to the ground is 0.

Let us know if you have any other questions.

John

[kajetankurtek]

Hi @John_Holtz ,

Thank you for the response. Just to make sure, while assigning boundary condition to the ground, in the dialogue box I should select the Component Method, enable the suitable axis, and for example if I want the car to be moving 20m/s, put in -20 as a magnitude?

Kajetan

[sara_in_mood]

You can model moving ground in Autodesk CFD by adding a moving wall boundary condition to the ground plane, matching the car’s forward speed. This helps replicate the relative motion between the car and road surface for more accurate results. We’ve applied similar aerodynamic principles when refining vehicle behavior in our multiplayer driving game.