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How to mesh a cylinder on a flat surface
Posted Jan 6, 2016, 1:35 p.m. EST Mesh 1 Reply
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Hi,
I am using the RF module and trying to mesh a cylinder with rounded ends laying on a substrate to see the plasmonic fields and interaction with the substrate.
The problem i'm having is the curved surface of this cylinder meets the substrate along just a single edge (its long axis) and produces an extremely narrow gap that is difficult to mesh. Whenever I solve it I get the warning "Using linear geometry shape order for mesh element at coordinates ...". From what i've read this means the meshing in this area is unsatisfactory and will give inaccurate results (extremely high E-Fields seen). I have been playing around with the mesh for a long time but the only way I have been able to avoid this is to slightly drop the nanoparticle into the substrate or slightly raise it above. This isnt ideal for me so I was wondering if anyone has any tips or experience meshing this kind of geometry?
One possible method to improve the meshing is to Form Assembly instead of Union and mesh the NP and substrate seperately however I cannot get it to show the same plasmonic response as with Form union. Guess this has something to do with me having to input BC's for the NP in Assembly but not sure what to use here. Any thought / help would be appreciated.
I am using the RF module and trying to mesh a cylinder with rounded ends laying on a substrate to see the plasmonic fields and interaction with the substrate.
The problem i'm having is the curved surface of this cylinder meets the substrate along just a single edge (its long axis) and produces an extremely narrow gap that is difficult to mesh. Whenever I solve it I get the warning "Using linear geometry shape order for mesh element at coordinates ...". From what i've read this means the meshing in this area is unsatisfactory and will give inaccurate results (extremely high E-Fields seen). I have been playing around with the mesh for a long time but the only way I have been able to avoid this is to slightly drop the nanoparticle into the substrate or slightly raise it above. This isnt ideal for me so I was wondering if anyone has any tips or experience meshing this kind of geometry?
One possible method to improve the meshing is to Form Assembly instead of Union and mesh the NP and substrate seperately however I cannot get it to show the same plasmonic response as with Form union. Guess this has something to do with me having to input BC's for the NP in Assembly but not sure what to use here. Any thought / help would be appreciated.
1 Reply Last Post Jan 8, 2016, 10:25 a.m. EST
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Posted:
9 years ago
Hi Josh,
I am not sure if this explanation of mine will be suitable for your simulation purpose, but in order to get around the point contact problems in meshing, it is advised that you make a small flat shared boundary between the two subdomains. You can achieve this by overlapping the two subdomains and having Comsol to calculate the overlapping volume. And after that, subtracting the intersection volume from them. This will relax the mesh conditions, giving you a "sliver" face at the contact location, but it is surely easier for the mesh algorithm to handle these kind of narrow regions.
In the case of the Form Assembly option, you may let Comsol to create identity pairs. These are the boundary conditions, to which you have to apply the continuity equations yourself. Without your input, Comsol will not know how to treat those shared boundaries, or in other words, Comsol will not take care of the interaction between the subdomains for you, as in the Form Union case.
Hope it helps,
Onur
I am not sure if this explanation of mine will be suitable for your simulation purpose, but in order to get around the point contact problems in meshing, it is advised that you make a small flat shared boundary between the two subdomains. You can achieve this by overlapping the two subdomains and having Comsol to calculate the overlapping volume. And after that, subtracting the intersection volume from them. This will relax the mesh conditions, giving you a "sliver" face at the contact location, but it is surely easier for the mesh algorithm to handle these kind of narrow regions.
In the case of the Form Assembly option, you may let Comsol to create identity pairs. These are the boundary conditions, to which you have to apply the continuity equations yourself. Without your input, Comsol will not know how to treat those shared boundaries, or in other words, Comsol will not take care of the interaction between the subdomains for you, as in the Form Union case.
Hope it helps,
Onur