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Old   November 24, 2014, 05:51
Default modify mesh?
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Ived
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Hi all,

I am running simulation on my model from 270 CA to 750 CA and ICE is creating a lot of DBG files around 450 files in 10 hrs and CA is still at 274. I have killed the simulation to check the mesh now. I have created the result at 270 and checked for negvol and smallvol but i found zero such cells. I have gone through the .info file to find many warnings with cell *** has neg vol and also equation of state imbalance at cell ***. What can do more to identify the problem and modify mesh?

Last edited by Ived; November 24, 2014 at 10:06.
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Old   January 2, 2015, 16:48
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Hi,

I have the same problem. if you find a solution or a way to improve cells, please, could you share with me your solution?
Thanks.



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Originally Posted by Ived View Post
Hi all,

I am running simulation on my model from 270 CA to 750 CA and ICE is creating a lot of DBG files around 450 files in 10 hrs and CA is still at 274. I have killed the simulation to check the mesh now. I have created the result at 270 and checked for negvol and smallvol but i found zero such cells. I have gone through the .info file to find many warnings with cell *** has neg vol and also equation of state imbalance at cell ***. What can do more to identify the problem and modify mesh?
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Old   January 7, 2015, 10:03
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check, negvolume, icemethod, all
check, negvolume, 20
check, small, 1e-5, 20

I am no expert but do try these commands and find negative or small volume cells in your mesh at various critical angles. preferably at TDC, BDC, max valves overlap. Identify and modify mesh accordingly. The shitier the mesh more DBG files are created by ice.
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Old   January 7, 2015, 10:14
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Hi,

Thanks for your response.
But i know these commands to check the mesh for critical crank angles.
My question is that how can we modify the mesh except changing parameters of template and trimming panels?


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check, negvolume, icemethod, all
check, negvolume, 20
check, small, 1e-5, 20

I am no expert but do try these commands and find negative or small volume cells in your mesh at various critical angles. preferably at TDC, BDC, max valves overlap. Identify and modify mesh accordingly. The shitier the mesh more DBG files are created by ice.
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Old   January 7, 2015, 10:40
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You should be able to find it in Es-ice User guide. If not here it is for you. version 4.22.

Having identified the problem cells, you must locate them in the Trimmed Template. Generally, you can use the following procedure:
Position the mesh so the problem cell in question is clearly visible.
In the Trim panel, Get the component that has the problem cell(s).
Identify the equivalent cell location in the Trimmed Template.
Note that this method may not be effective if the cell is on a moving engine component such as a piston. This is because the piston position in the Trimmed Template is determined by Piston DZ (set in the Trim panel), whereas the piston position in the Create Result mesh or DBG file is at a user-defined crank angle. In such cases, you should select a viewpoint that makes the two meshes easy to compare. For example, when identifying cells on the piston, a view down the z-axis will be useful (as the piston moves in the z-direction) but not along the x- or y-axis.4. Once you have identified the equivalent cell in the Trimmed Template, you can fix it using one of the following methods:
The VMerge, Cursor command to collapse small edges
The Cdx tool to re-define the cell completely. In the Trim panel, Put the cylinder component back into the database and Assemble the Trimmed Template
Finally, run Star Setup and Create Result at the required crank angle to check that the fixed cells do not cause any more problems.

Hope this helps.
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Old   January 7, 2015, 11:12
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I have user guide, and really read it a lot of time. But I couldn't implement this solution to my model, because bad quality cells are inside model, not on the wall. I mean that I couldn't see it to modify.

Did you implement this solution your model and fix your problem?


Quote:
Originally Posted by Ived View Post
You should be able to find it in Es-ice User guide. If not here it is for you. version 4.22.

Having identified the problem cells, you must locate them in the Trimmed Template. Generally, you can use the following procedure:
Position the mesh so the problem cell in question is clearly visible.
In the Trim panel, Get the component that has the problem cell(s).
Identify the equivalent cell location in the Trimmed Template.
Note that this method may not be effective if the cell is on a moving engine component such as a piston. This is because the piston position in the Trimmed Template is determined by Piston DZ (set in the Trim panel), whereas the piston position in the Create Result mesh or DBG file is at a user-defined crank angle. In such cases, you should select a viewpoint that makes the two meshes easy to compare. For example, when identifying cells on the piston, a view down the z-axis will be useful (as the piston moves in the z-direction) but not along the x- or y-axis.4. Once you have identified the equivalent cell in the Trimmed Template, you can fix it using one of the following methods:
The VMerge, Cursor command to collapse small edges
The Cdx tool to re-define the cell completely. In the Trim panel, Put the cylinder component back into the database and Assemble the Trimmed Template
Finally, run Star Setup and Create Result at the required crank angle to check that the fixed cells do not cause any more problems.

Hope this helps.
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Old   January 8, 2015, 05:44
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Yes. Cells inside the model are not a problem. Use appropriate commands in es-ice to locate the problematic cells and fix them.
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Old   January 8, 2015, 06:00
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OK then, i will try to implement it again. Thank you for your support.
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