SimScale CAE Forum

Error in meshing


#1

hi everyone ,
i am participating in upcoming simscale contest 2019. i was simulated one part and i face some issue in meshing.
meshing error :point_down:
β€œThe machine ran out of memory. Please choose a larger machine by increasing the number of computing cores.”

i face this problem lots of time and i know if i decrease refinements then this problem will solve.
but in this contest there is one ponit .
Community Challenge Judging Criteria:point_down:
–––––––––––––––––––––––––

  • Quality of the meshing and simulation setup

if i reduce the refinement it will work for me but this is not a β€œQUALITY OF MESHING” so, can simscale increase my computing cores for only 1 month ? if not, then please shear alternating option to solve this problem without affecting mesh quality.

Thank You,
Rohit.


#2

Hi Rohit,

is it also related to the project in the other thread? If not share the project and if it makes sense to increase the fineness I can run the meshes for you. Upgrading the account would allow people to set projects to private which would be against the rules.

Best,

Jousef


#3

hi jousef
here is project link:point_down:
https://www.simscale.com/workbench/?pid=3023301305500093616&mi=spec%3A03921cdb-45bc-4d74-bb9f-753ecea9e736%2Cservice%3ASIMULATION%2Cstrategy%3A1
please run the mesh for me.
thank you,
rohit.


#4

Hi Rohit,

have you performed a convergence study already to see if you reach a plateau at some point? For me level 7-8 is a very fine refinement and might not be needed. @Get_Barried what do you think?

Cheers,

Jousef


#5

Hi everyone,

7-8 is def much too high. You don’t need that level of fidelity unless its a very specific area you need to refine. My advice to keep the cell count and simulation time down is to start with surface refinements between 2-3 for larger areas, 3-4 for smaller areas and add on feature refinements with 0 length and refinement level 3-4. Once this mesh is of sufficient quality and the cell count seems reasonable, then move on to adding layers.

The current geometry is a single piece, hence you will get the meshing problem you see now as shown below. You need to split the surfaces first then proceed to mesh. Since as mentioned you want to split 2 general surface refinements, the splitting will allow you to select the areas that you want to specifically refine. That is also important for layer generation as you might want to select only specific areas to inflate your layers as inflating everything might decrease overall cell quality.

Hope this helps.

Cheers.

Regards,
Barry


#6

thank you for your great advice.:grinning::clap:
i will change my part file.
and follow your advice for refinement.
thank you,
rohit


#7

hi everyone,
I face problem in meshing :point_down:

i was trying to find the problem my self and i was found some area where the actual problem can happen.
my mesh box content mini 0.03 m value and max 1.2 value

and my Surface refinement area content max 3m n 2m

Surface refinement area has more value then mesh box so can this is the main reason for failure?
and i use only two refinements because i was followed 2017 f1 webinar

project link
https://www.simscale.com/workbench/?pid=8474346144209101048&mi=spec%3A1956167f-5814-4137-94f1-c2dcc1f0dc3a%2Cservice%3AMESHING%2Cstrategy%3A2&ps=algorithm%2FHexDominantSnappy--oneOf%2Frefinements%2F0&sh=1

please help me
thank you,
rohit!


#8

For a start perhaps find and remove these small faces on your geometry:


#9

Hi Rohit!

You have chosen the internal automatic mesher. It should be the external one for such a case and if you follow the old tutorial use the parametric mesh option anyway to adapt each setting manually.

If you choose the automatic one make sure you increase the fineness for resolution as the thrown message states.

Best,

Jousef


#10

hi @DaleKramer
thank you for your reply:+1:
but how I can find this small face in my geometry?:thinking:


#11

Hi Rohit,

finished a mesh - shared it with you. Looks good I would say. You can add additional refinements around the wing if necessary.

Best,

Jousef


#12

hi @jousefm sir

I WAS INCREASE THE MAXIMUM RUNTIME 3000S TO 5000 IN RUN3 BUT THERE IS PROBLEM
PLEASE HELP ME
PROJECT LINK
https://www.simscale.com/workbench/?pid=3551733751828840133&mi=spec%3A48851bb0-1dcb-44e9-8ec6-dea1892f0bac%2Cservice%3ASIMULATION%2Cstrategy%3A1&ps=analysis%2FIncompressible--oneOf%2FsimulationControl


#13

Hi Rohit!

Increase your runtime to 30,000 that will work. P.S.: You have caps lock on :wink:

Cheers!

Jousef


#14

hi @jousefm sir,
finally :star_struck:the RUN was successful.
thank you for your help me meshing and runtime setup :clap:(still i don’t know how you can say directly to increase the runtime from 1000s{ default value} to 30000s ?)

NOW the most important thing is for me to find the force(in N) on the different part of the wing SO, I will calculate the total downforce on the wing surface.
so if you have any tutorial link about this topic please send me.
thank you,
ROHIT:grinning:


#15

Hi @ROHIT_SR,

You will likely need to perform the post-processing offline in ParaView. This particular video should help you. Basic principles are the same if you need to change the type of data you want to look at (calculator function). Surface extraction should allow you to determine which surface you want to check.

Cheers.

Regards,
Barry


#16

HI @Get_Barried
thank you sir for this video :grin: