Hi @anurags
Are you still facing some issue in this simulation coz I saw your project and the “mesh 2 verification 2” simulation is working in the desired manner. If you have any other issue plz don’t hesitate to share with us.
Thanks
Ani
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@anirudh2821998 No it is not working. Please see the project titled Centrifugal Pump. The one you saw is just a public project.
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Hi @anurags and @sriramchari1
EDIT: Sorry, I couldn’t give an extensive explanatiopn on how I solved this issue as I was busy preparing for my exam. Here is the method I use when I work with MRF problems.
- Your CAD will play a very imp. role in the process of formation of a new cell zone. I usually make my CAD model in this format-
In your CAD models your blades are solid so, my first step was to use boolean cut operation to make that cavity in both the MRF cylinder and the main body. Thus there was no need to make a new assembly from scratch. Then I made a new mesh with MRF zone by using the “with cell zone” option in the surface refinement .
I made some modifications in the CAD model and now the MRF zone has been created properly and it is now able to assign B.C’s to the mesh surface. I am attaching the project link here- https://www.simscale.com/workbench/?pid=8500429970281485035&mi=spec%3Ad0d56b41-419e-4911-b8f5-5ef054630107%2Cservice%3ASIMULATION%2Cstrategy%3A2
You can either download the CAD model and assign desired mesh refinement in a new personal project or you can simply copy my project and work within it. Hope that helps 
Thanks
Ani
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Thanks for reporting this @anurags!
This should usually be no problem, already reported that to our engineers to fix this issue. We will keep you up-to-date about the progress!
Jousef
Hello,
Unfortunately, I have run exactly into the same problem. my case is here:
I have also tried to modify the case prepared by anirudh2821998, but it has a different problem: the blades have a rough surface * case: https://www.simscale.com/workbench/?pid=8801242825754213671&mi=spec%3A6b497a44-009d-4025-b3cf-00d8d3a5e0b3%2Cservice%3AMESHING%2Cstrategy%3A19&sh=2)
Do you know another way around that issue?
Thank you,
Stan
Hi @ephiopia93: Please take a look at small demo project I’ve just created. Internal CFD with MRF. This should allow you to sort out those problems.
Cheers,
Retsam
3 Likes
Retsem,
Thank you very much for your answer. I have tried to rerun your case, but the same issue occurs: the mesh is not assigned to the domain. In addition, using the method presented by [anirudh2821998] gives a poor mesh quality and crashes. I use all boundary conditions as in one of the examples I found in the public domain, so I suspect the problem is in the mesh. Could you help me with this issue?
Thank you,
Stan
Hi Stan,
I do not see, in the posts of this topic, where Retsam provided you a case to run, how were you able to re-run his case?
I opened your case in your post #7 and the first thing I see is that there are still 3 solids, in the only geometry, in that project.
In Retsam’s Post #8, he shows you a project that he created to help people currently having a problem with internal MRF simulations. Currently you must follow his recommendations and if you did, you would have only 2 solids in your geometry.
Please modify you geometry accordingly and try everything he suggests in his sample project…
Regards,
Dale
2 Likes
Hey guys!
The issue has been resolved and the error message “Mapping of assignments from geometry to mesh failed” should no longer appear. Let me know if you have any further questions.
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Hello @anirudh2821998,
During the assembly of body 1 and body 2, wouldn’t the surfaces of of blade cavity in body 1 overlap with the surfaces of blade cavity in body 2? So, though the surfaces will be joined to each other , they still act as two different surfaces. How to provide boundary conditions for both the surfaces, to make them act as one?
Thanking you.
Regards,
Yash Agiwal.
Hi.
I believe the project is already public:
Thanks,
Goku
Hi Goku!
Was a problem with the project name that it converted the link incorrectly. So I do not see any problems (let alone errors) inside your project - can you tell us what the issue was?
Best,
Jousef
Hi Jousef,
I was following the tutorial that I linked above, and set all of the values as it said to. But, when i tried to begin a simulation i got these two errors:
I am not sure on how to resolve the second error.
Thanks,
Goku
Thanks for reporting this Goku!
Will forward that to our engineers - we will tackle this as soon as possible. Getting back to you when I know more.
Have a nice weekend!
Jousef
I am still getting similar errors:
- Mesh cannot be selected for boundary conditions
- Prop inside the refinement boxes not being meshed - I tried both making it a solid and negative geometry inside the fluid domain.
- After meshing (and spending core hours) I get this message
Here is the link to the project: https://www.simscale.com/workbench/?pid=3724086337920935062&mi=spec%3A49cdd096-10f0-4d5b-b222-ce2f8d931fd7%2Cservice%3ASIMULATION%2Cstrategy%3A24&ps=analysis%2FIncompressible--oneOf%2FboundaryConditions%2F0
Hope you guys have some insight
Hi @joshuaxdmb!
You can just click on the button to use the mesh as the domain, that’s fine. Also regarding your setup before you jump back to it.
You want the cylinder to rotate using the MRF approach, right? I would personally increase the domain to make sure the boundaries do not affect the results. CFD Squad, what is your take on that?
Best,
Jousef
You’re right domain will probably need to be larger, but I want to make it work first.
Using the mesh as domain still does not solve the problem tho. The prop is still not being meshed - neither as a part or as a cavity inside a part.
I am trying hex-dominant parametrix. It’s taken 12 core hours and only 50% done.
That’s not that much tbh. Could also be that your refinements are too coarse. CFD Squad, can you make some suggestions here?
All the best!
Jousef
Hi Retsam, I am trying to setup a simulation similar to your example, but for some reason it is not working. The propeller inside the rotating region (which is negative geometry) is not being meshed. Do you have any insights?
Here is the link to one of my setups - I have been trying different setups with small variations to see what happens: https://www.simscale.com/workbench/?pid=2591225129477023134&mi=spec%3A29848356-7db5-4d95-8729-f14339973ac8%2Cservice%3AMESHING%2Cstrategy%3A47&sh=24
Appreciate any help!