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Posted:
1 decade ago
2010年1月23日 GMT+1 13:23
It would help if you describe your model in some lines.
It would help if you describe your model in some lines.
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Posted:
1 decade ago
2010年1月24日 GMT+1 01:00
It would help if you describe your model in some lines.
Hi Daniel
Thank you very much for your message. The model is attached below:
www.4shared.com/file/203837477/2bf3f9b7/test.html
As you can see, I have added some support line to prevent the mesh to get inverted. As I increase the pressure gradient the solver diverges. I am not sure about the solving method and time steps that I have chosen but I have tried different mesh models and different support lines. Non of them helped me so much. The desired pressure gradient is 900 ...
Please have a look at the file and kindly let me know your suggestions,
Regards,
Hani
[QUOTE] It would help if you describe your model in some lines. [/QUOTE] Hi Daniel Thank you very much for your message. The model is attached below: http://www.4shared.com/file/203837477/2bf3f9b7/test.html As you can see, I have added some support line to prevent the mesh to get inverted. As I increase the pressure gradient the solver diverges. I am not sure about the solving method and time steps that I have chosen but I have tried different mesh models and different support lines. Non of them helped me so much. The desired pressure gradient is 900 ... Please have a look at the file and kindly let me know your suggestions, Regards, Hani
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Posted:
1 decade ago
2010年1月26日 GMT+1 19:59
Hi Hani,
I cannot access your file. Maybe you try another file sharing?
The file link that you requested is not valid.
Danial
Hi Hani, I cannot access your file. Maybe you try another file sharing? [quote]The file link that you requested is not valid.[/quote] Danial
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Posted:
1 decade ago
2010年1月26日 GMT+1 22:04
Sorry,
I attached the file.
Regards,
Hani
Sorry, I attached the file. Regards, Hani
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Posted:
1 decade ago
2010年1月26日 GMT+1 23:43
Sorry,
I attached the file.
Regards,
Hani
Try using Heaviside functions on your pressure to ramp it up to the final value. In your inlet pressure I used P*flc2hs(t-0.1,.1), and I got the following result (attached screenshot).
[QUOTE] Sorry, I attached the file. Regards, Hani [/QUOTE] Try using Heaviside functions on your pressure to ramp it up to the final value. In your inlet pressure I used P*flc2hs(t-0.1,.1), and I got the following result (attached screenshot).
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Posted:
1 decade ago
2010年1月27日 GMT+1 00:21
Thank you very much. In fact I have tried that as well. I made a ramp from time zero to 2, that the pressure reaches 300 and from t=2 to t=3 pressure is constant p=300. Again the cycle is not completed and it crashes at time 2.67. The file is attached.
What about the model that you tested, as far as I see, it has crashed at t=0.52. Am I right?
The other possibility is to make the channel longer after the moving parts in order to reduce the effect of outlet on the fluid. But again in that case, I could not get any result....
Thank you very much. In fact I have tried that as well. I made a ramp from time zero to 2, that the pressure reaches 300 and from t=2 to t=3 pressure is constant p=300. Again the cycle is not completed and it crashes at time 2.67. The file is attached. What about the model that you tested, as far as I see, it has crashed at t=0.52. Am I right? The other possibility is to make the channel longer after the moving parts in order to reduce the effect of outlet on the fluid. But again in that case, I could not get any result....
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Posted:
1 decade ago
2010年1月27日 GMT+1 11:28
No it didn't crash; I just stopped it, as I was running it my laptop.
I will try again today and report back
No it didn't crash; I just stopped it, as I was running it my laptop. I will try again today and report back
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Posted:
1 decade ago
2010年1月27日 GMT+1 17:33
I will appreciate that.
I will appreciate that.
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Posted:
1 decade ago
2010年1月27日 GMT+1 17:43
Hi Hani,
I tried some more simulations, and I can say so far that mesh around the neck is a very important part. So I refined the mesh in that area and I could simulate a bit further. How about you draw the mesh quality and improve the parts that goes low.
Hi Hani, I tried some more simulations, and I can say so far that mesh around the neck is a very important part. So I refined the mesh in that area and I could simulate a bit further. How about you draw the mesh quality and improve the parts that goes low.
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Posted:
1 decade ago
2010年1月28日 GMT+1 04:39
Yes. That would be a good idea. I will do that. What about the solver. In fact I ma not a finite element man, I do not know how to decide between different solvers and which one is more suitable for this problem. Do you have any idea? UFMPACK, SPOOLES, PARDISO?...
Thanks
Yes. That would be a good idea. I will do that. What about the solver. In fact I ma not a finite element man, I do not know how to decide between different solvers and which one is more suitable for this problem. Do you have any idea? UFMPACK, SPOOLES, PARDISO?... Thanks
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Posted:
1 decade ago
2010年1月28日 GMT+1 09:49
I usually use Pardiso, maybe sometimes UMFPACK. I set the Gen-a solver with 0.5 for frequencies and type of scaling to manual (or none). But it really depends on your problem and needs a feeling for it.
I usually use Pardiso, maybe sometimes UMFPACK. I set the Gen-a solver with 0.5 for frequencies and type of scaling to manual (or none). But it really depends on your problem and needs a feeling for it.