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This errors has something to do with the mesh size. I got this error when I was trying to refine the mesh near a singular point in my model. However, by using coarser meshes, I didn't see it. Hope this helps. Amin
Failed to find consistent initial values. Undefined value found. NaN or Inf found when solving linear system using SOR. Last time step is not converged. - Feature: Time-Dependent Solver 1 (sol1/t1)
I am simulating a RC beam, which I want to load a displacement of 4mm/s, I do not know how to implement this in Comsol. Should I use "prescribed displacement"? In addtion, I have met the error ' Iteration of finding elasto-plastic strain variables did not converge" when I used the "prescribed displacement". Thank you.
hi. I want to simulate motion of two large particle that immersed in a fluid chamber. the particle move by dielectrophoresis forse. I use the fsi model of comsol. but the simulation diverged very soon. can anyone help me???? please
when i simulate a turbulence flow, i see the velocity on walls is not zero. anyone know about this??
Hi,
I set up a simple test case to understand COMSOL and FE simulation, however, could not understand the result.
2D, linear elastic material in solid mechanics interface, stationary study step. a block of aluminium. Initial location of this block is (0,0)
two study steps:
1st step, move the block for 1 meter with "prescribed displacement". location of the block is (1,0);
2nd step, set the result of the first step as initial "values of dependent variables", and remove all the boundary conditions.
to my surprise, the result of the 2nd step showed that the block moved back to (0,0) instead of staying at (1,0).
Could someone explain me the drving force of this movement? Is there any way to keep the block stay at (1,0) without any boundary condition except for "free"?
the .mph file has been attached.
best, Chi
Hi Could someone tell me if Comsol is able to analyze noise produced by a water pump? If yes, is there any example to be shared with me?
Tx in advance
P. SOUBIRAN
After the call from Matlab, we failed to save the model, and the Eerror Message is :"Failed to save model. The file 'aa.mph' is locked by another program." Using "clear all""clc" in Matlab is ineffective. So how to deal with this problem. Thank you !
Hi
I have an optical fiber simulation running on Comsol 5.1. I have a fiber with a tapered end and am using the Ray Optics module with rays tracing showing rays propagating along the fiber. I would like to calculate the power/transmittance in the cone at the tapered end.
How would I go about doing this?
I have used the Deposited Ray Power node to find transmittance with the fiber having an open end because it uses boundaries only, but I don't know how to do it with a cone end as this is a domain. I think it would have something to do with a volumetric integration. Any help is appreciated.
Thanks
I'm trying to build a finite element model for an acoustic metamaterial, where losses play an important role. However, I'm having some trouble when combining the thermoacoustics physics with Floquet boundary conditions.
In the case of the pressure acoustics model, the system predicts resonance frequencies that are in reasonable agreement with the experiements. However, when using pressure acoustics the resonances completely change. I'm using a boundary layer mesh with 8 levels and considerable resolution, and refining the mesh further doesn't seem to impact the results.
Any idea what may be going on?
Attached a comparison between pressure acoustics and thermoacoustics.
Hi all, I want to construct a hologram and want to use it to interact with Au particles， Is it possible in comsol multiphysics? Can anyone suggest me which module should i use? and how would it be possible? Thanks for a lot for any help.
Hi, I am new to comsol.I have created a geometry which has glass fibre block on which there is a platinum strip to study the Joule heating due to current flow through platinum strip. On computing it shows the following error message: Failed to find a solution. Maximum number of segregated iterations reached. In Segregated step 2: There was an error message from the linear solver. The relative residual(0.68)is greater than the relative tolerance. Returned solution is not conerged. Please help me to find out what the error means and what should I do to compute the program. With Regards Minna.
Can it be possible to import FORTRAN script in initial values? Instead of sine wave as initial condition we want to use random initial wave condition. The random wave initial condition is in FORTRAN language script. Otherwise can we run it as MATLAB code and import it to initial value condition?
Hello all,
I am trying to solve a turbulent channel flow with Re of order 10000. I am using a SST model.
I am trying to plot uplus and yplus values and finally find wall shear stress values to verify my results. But i am unable to access the uplus and yplus values.
Could anyone give me a lead with respect to same.
Regards, LN
I'm running a comsol model on a cluster using the syntax:
comsol -clustersimple -nn 5 -f hostfile batch -inputfile <filename.mph> -study std1 -outputfile <ofilename.mph>
This runs if the number of domain elements are such that the memory required does not cross that which is available on a single node. Although I get an error saying Error on node 1, Error on node 2, ..., the outputfile contains results that I believe are complete.
If I run the case with increased number of domain elements such that the memory required is more than that available on a single node (the reason for which I would like to use cluster computing), the simulation runs for 20 or so minutes and ends with a bad termination error with Exit code: 9. I've attached a screenshot of the error. Ideas and suggestions? I'm using a FNL of course.
Thanks and regards,
Hello all together,
I have a Problem, which maybe have been discussed several times in a way here, but not for this special case.
I am simulating a 3D model of an anode in a battery.
The 3D model particles are surrounded with binder which contains active material to connect the anode particles with the conductor and also simulate the porosity around the particles in the electrolyte. The binder is modeled as a porous electrode.
Is it possible to connect in a solid the transport of diluted species module(cs=Lithium-concentration) with the diffusion module of a porous electrode(lithium-ion-battery module)? So that I have a Lithium-flux out of an solid electrode into a porous electrode where it is transported further?
And how ?
So that the lithium-diffusion of the solid electrode is connected to the porous electrode which surrounds it. Of course the other way round as well.
Thanks, Greetings Daniel
Hello,
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Hello,
I want to implement a rotating ring and a cube, that gets in contact with the ring and adds friction. This should happen with plastic deformation. So far I understand that one cannot combine plasticity in solid mechanics with multibody dynamics via multiphysics but with an attechment node and joint. But I have problems with assigning the domains to both solid mechanics and multibody dynamics at the same time. So my question is, how do I assign the domains that I have rotation (multibody dynamics) and plastic deformation (solid mechanics) in my model?
Thanks for your help in advance.
Hello, I noticed that once i apply rigid domain to my 2D model in solid mechanics, the rigid connector becomes invalid. What is another way to keep the solid fixed (not let it move in x and y direction) but allow it to rotate? Any help is appreciated. Thanks.
Hi,
I am modeling a mems resonator. The resonator has electrodes attached to it (rectangle bars in image). Underneath the electrodes are another set of electrodes which are fixed. Electrodes attached to the resonator (mass) are movable (top electrodes). I am applying a positive and negative dc and ac voltages to the fixed electordes. Thus producing an electric field. This electric field is suppose to push the movable elctrodes, which are right above the fixed ones, away from the fixed electrodes (out of place displacement). Unfortunetly this is not happeing.
I have tried various changes to my model. I am getting various errors.
I have also included an air domain (with and without it; i am getting errors). When i chose the air as the material, it asked me for young's modulus and possion's ratio. This doesnt make sense to me, but i think the problem is deeper.
If someone can help me getting this simulation running that would be greatly appreaciated.
Thanks in advance.
-Nabeel
