[SOLVED] Comsol v4.3.0.233 crashes
Hi, Today, after restarting my machine I opened several applications and I was logged out from my desktop session. After checking one by one, I get to see it was comsol that was giving problems. I've...
View ArticleChanging the relative repair tolerance seems not to be effective in any way
I need to define a geometry that is very awkward but it's necessary, It's a sphere with a very big radius compared with the thickness of a single layer (1000 times smaller, e.g. s/r = 1e-3, where s =...
View ArticleConvergence of time dependent and linear solver
Hello All, I am trying a model in which electrodes can electrically stimulate certain layers having different conductivity (input being a biphasic pulse train). Using time dependent study, the model is...
View Articletime interval for automatic remeshing
Hi, I would like to know the COMSOL keyword for the time interval when using the automatic remeshing module. I want to define a criterion based on the time that's why I need to know the actual number...
View ArticleIntegral Constraint
Hi, I am using the Nernst Planck Module (chnp) on Comsol 4.3 and I want to create a constraint so the total current in a boundary it's equal to 0, but I have no idea how to do it. Can any body help me?...
View ArticleInitial values error using mapped mesh
Hello, Every time I try to use a mapped mesh for a time dependent simulation I have the following error : --- The following feature has encountered a problem : failed to find consistent initial values....
View Articlegas mixture
Hi I am trying to model an ejector with 2 inlets and one outlet. In the first inlet I have hydrogen with low pressure, in the second inlet I have (hydrogen 30% + steam 70%) with a higher pressure. The...
View ArticleOverride not-applicable boundary
Hi, This may be easy but I don't see how to do it in V4.3a. In V3.5a it was not hard. I would like to apply convective cooling at an interior boundary in my model. Currently, all the interior...
View ArticleExport Image through script
I would like to be able to save an image of my plot using a script. I thought opening my script and going to export image in the GUI would add the steps to my m file but that didn't work... Thanks
View Articlemicrofluidics
hai all my geometry is a rectangular having 10mm in x direction and 1mm in y-direction. the first half ( up to x=5mm) consists of one fluid and second half consists of other fluid having same...
View ArticleState Space Export
Hi , i have build a simple cantilever beam model using time depented model. after defining the points of forces and parameters, i want to export the model to matlb (State Space Matrices) so i could...
View ArticleHow to plot the relative error?
I've just spent more than a whole day troubleshooting my model. However, if I could plot the relative error over the geometry, I believe it would have been solved in minutes. There was a problem...
View Articleacceleration due to gravity Laminar flow
I want to give acceleration due to gravity effects to fluid in Laminar pipe flow, any one know how to give,????? I have tried by applying domain volume force like 9.81*density of fluid but i am not...
View ArticleSimulating an expanding plasma plume
Hello, There are two ways (at best of my knowledge) we can simulate the expanding plasma plume due to the irradiation from a laser on a target. 1. Particle tracing module 2. Fluid model. We are working...
View ArticleHow to set boundaries as continuity ?
I want set the boundary as a continuity but I don't know how? I know that in Comsol by default the boundaries are define as continuity and it follow this equation: n.j=0 but I want change it to n(j1-...
View ArticleFluid structure interaction with Turbulence k omega model
Hi, I want to study he effect of blood(fluid )on arteries wall layers(structure ). so i have been trying to model it with FSI and turbulence K omega. There is in inlet velocity waveform that is...
View ArticlePlasma electron impact reaction
In plasma simulation If i have the reaction Metastable –metastable associative ionization Hes+Hes=>He2++e with rate constant, k and threshold energy -18.2 where Hes is metastable Helium and He2+ ion...
View Articletransmission spectrum for beam focusing in plasmonics
Hi everyone Iam trying to simulate using the RF Module beam focusing through subwavelength slit using grating but unable to get transmission spectrum i hv defined two port one side it is small in width...
View ArticleCreating (and using) an involute coordinate system
I've defined an involute coordinate system using an interpolation function. For an unstructured grid of x and z coordinates, I have defined two new coordinates t_coord and h_coord which have vectors...
View ArticleStore data at certain time intervals
How do I set up my model so the data are not stored at every time step, but at certain intervals. That way I don't end up with huge file, and my plot files for exporting are small as well. Thanks in...
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