"The meshing algorithm failed with a floating point exception."

Hi everyone,
I’m a student who participate to Formula Student in France and I am in charge of the aerodynamics department.
Currently, we want to simulate the airflow around our car but I have a problem with the mesh : The meshing algorithm failed with a floating point exception.
Here is the link to my project for anyone who wants to help us : SimScale Login
The simulation with the problem is called : “Incompressible ET-21 avec aéro”

Thank you everyone and let me know if you have any further question

Hey there!

It seems like there are some modeling problems in your geometry, for example in this area:

Please check the model in your CAD, and clean it for interferences and small faces. Also, I can see parts intersecting each other, which can also cause problems. Please also fix those cases, for example:

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Hi, thanks for your answer. Unfortunately, despite the changes made, I still have the same problem…
Best regards, Johan

Hi @jmazet

I had a look at your case and here are some pointers:

  1. As my colleague @ggiraldof mentioned, the struts connecting wheels and the body are not modeled to touch each other. You can extend the struts and then do a boolean → union to merge them.
  2. For an external Aerodynamics simulation we would need to create an enclosure around the body of the car to imitate the wind tunnel setup. This can be done within SimScale’s CAD mode and choosing the External Fluid volume operation. Here is an article that shows the workflow: How to Create Flow Volume Extraction? | Knowledge Base | SimScale

Once you create the External flow volume, you can follow the tutorial on Aerodynamics Simulation of Flow Around a Vehicle
to get an overview of the setup.

Please let us know if that helped. Happy to assist further.
With Kind Regards,
Ajit

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Hi @ananthu_ajit
In the last mesh I tried to generate, I think I have corrected all the problems caused by the CAD, but if you can confirm this, I would be grateful.
Secondly, we have already done a lot of aerodynamic simulations without the external fluid volume operation and all simulations were successful. I don’t really understand the point of this tool, can you tell me more?
Thank you very much for all your answers
Johan

Hi @jmazet

I see that you are using the “Hex-Parametric” mesh to create the background box. This looks valid without an External Fluid volume. But is prone to errors often. The latest CAD geometry has all the parts modeled as Sheets and this might cause the mesh to fail. I would recommend looking into the CAD and check if you can convert them into solids before importing.

The previous model ( T21_30_30_R0_4) looks ok with Solids, except One part where many solids are put together and has a few edges interfering with each other.


Can you please look into the CAD tool and see if you can clean up these interferences?