SimScale CAE Forum

Yaw Simulation for a fsae car


#1

I’m trying to create a curved bounding box so as to simulate a car taking a turn. I tried making a bounding box on my cad software and then using it but the simulation failed, is there any option to make a bounding box similar to a toroid or torus?


#2

Try using the extract fluid volume on a CAD file that has your curved bounding box on it and then do an internal simulation with it… But I do not think you will like the results you get by trying to ‘curve’ your flow…


#3

Hi @markII!

That’s possible, meaning the simulation of “cornering” not the creation of a curved bounding box! Let me give you some resources for that:


Let us know if that helped!

Jousef


#4

I used that term loosely here… with internal fluid extractions, the outside wall is a ‘sortof’ bounding box that can be any shape you want :wink:


#5

Same here, I should have mentioned that you can of course create an arbitrary shape for your bounding box but not on the platform, so you would have to choose a CAD software tool of your choice @markII! :wink:

Hope we could help you a bit!

Jousef


#6

But NOT if you plan to use HEX parametric meshing algorithm (SimScale, please allow internal meshing with HEX parametric meshes :pray: )


#7

Well, I use HEX parametric for Internal CFD.

The project (I shared with you and Ric) is https://www.simscale.com/workbench/?pid=6414850718207970462&mi=spec%3Add5e8f5e-7f49-42ad-a61a-7cf083178f8e%2Cservice%3ASIMULATION%2Cstrategy%3A56

Simulation: CylinderSlice_HEX+MRF

Cheers,

Retsam


#8

WOW, I stand corrected then, my memory is old on that one, thanks…


#9

Maybe you can help with the mesh attempt at this Oct 2019 post where I try to do it?


#10

WOW, great trick I just learned from you Retsam… I have to put a Background Mesh Box around/through my geometry and then select geometry faces for inlet,outlet,‘tunnel’ walls… :trophy:

Darn, I wish I would have thought of that :thinking:

EDIT: But wait, I did do that in my problem mesh above… @Retsam what went wrong :question:

Now I am a dog with a bone again here :wink:


#11

I do not know what went wrong: For Internal CFD, I create my own BMB of any shape. It does contain a ‘negative’ of all geometries to simulate. So, If you assign the BC to that BMB, there is no problem. All internal geometry should be available for detailed BC definitions…


#12

I guess Alex @afischer , couldn’t figure out why it would not work for my case too, since the topic was left unsolved … :sob:


#13

Dale, what problem did you have in that case? I can reach out to the Fluid guys in our office so that one can reach out to you ASAP.

@Retsam, could you set the project to public? Cannot access it, thanks!

Cheers,

Jousef


#14

I will post a clarification of the problem in that topic, thanks… (Ooops, sorry if the non-powerusers do not have access to this issue, I created the Oct 2019 topic in the powerusers hidden forum category )


#15

Yes, I did make it Public now…


#16

Hi @DaleKramer,

I just really quickly checked your project. From the cell count and log you can see that your mesh simply resulted in a single hexagonal cell. I would need to check the sizing, but that’s a special point about the underlying meshing algorithm that it always creates a mesh even if the geometrical domain is captured in a totally invalid way for simulation. That doesn’t mean that you can not create internal meshes with the parametric mesher. We detect if the point is inside a body and in case there is a one to one map available also allow the simulation setup on the CAD.

Best Alex


#17

You lost me there, is this trying to explain why Retsam can do it with his geometry and I can not do it with mine ?


#18

No, my suspicion is that it didn’t work as I guess you are trying to create a quasi-2D mesh with only 1 cell over the thickness which resulted in a single cell for the whole mesh.


What to do if geometry does not appear in your mesh - try the Feature Trick
#19

I will leave it to the coders and mathematicians to figure out why this Feature Trick made my ‘eye’ shaped BMB and geometry appear, but it did…