[Ibbyza]

Hi everyone, I am a uni student learning CFD on my own and im using star ccm+ to do my FSAE assignment. I'm using youtube, steve portal and other forums to learn and I am always reaching frustrating moments where i am stuck and cant move forward. I would like to pose some problems in this forum with the hopes that these doubts can be clarified. If any of you are wondering what my simulation is like, i try to copy it with the fsae resource technical guide exclusively in the steve portal ( shout out to that guy, he made it really simple )

1st issue : After importing cad -> creating fluid domain-> assign parts to regions.. i sometimes come across an issue when i want to run the automate mesh. It says 'SUBTRACT SURFACE INTERSECTS ITSELF'. i look around in my mesh and couldnt see any problem , maybe to an untrained eye like mine it makes no difference, so after days of playing with the programme, i realized that if i increase the base size slightly, the problem goes away. So i want to know what exactly was the issue?


2nd issue : This is the craziest one.. and most frustrating. After doing the local coordinate systems for the tyres, adding physics and putting my monitors/reports and finally pressing run.. the sim will not run. it says conjugate solver did not converge and i can seem to find a way to troubleshoot it. for this issue, i have posted it on the CFD subbreddit but have yet to receive a solution. the link will be below so that there u can find some links for the images in the comments.
https://www.reddit.com/r/CFD/comment...with_star_ccm/

PS- thank you for taking the time to read this and if you have any suggestions pls feel free to let me know.. at this point i'll do anything to solve this. take care and stay safe all.

[cwl]

Not quite sure which surfaces correspond to Interface 1 - but screenshot at Reddit says that there is 96%/97% intersection.
Sometimes few small faces not recognized by the interface and thus "hanging" as walls can cause problems.
From what you've described (not much information provided) - I'd suggest checking those surfaces at Interface.

[Ibbyza]

Originally Posted by cwl

Not quite sure which surfaces correspond to Interface 1 - but screenshot at Reddit says that there is 96%/97% intersection.
Sometimes few small faces not recognized by the interface and thus "hanging" as walls can cause problems.
From what you've described (not much information provided) - I'd suggest checking those surfaces at Interface.

Hi , that interfaces corresponds to my radiator(inlet is 1 , outlet is 2). what do you mean by 'check those surfaces' , what am i looking for exactly and how do i remedy it?

update: i deleted the interfaces just to try if the simulator will run, and it gives of the same thing,
"A floating point exception has occurred: floating point exception [Invalid operation]. The specific cause cannot be identified. Please refer to the troubleshooting section of the User's Guide.
Context: star.turbulence.TurbUstarSolver
Command: RunSimulation
error: Server Error"