In the Comsol conference article, I saw the magneto-caloric effect simulated by A. Noume related to the article, but I do n’t know how it was made, and I do n’t know if anyone can help.
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Simulation of magnetocaloric effect
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Modeling gas-solid non-catalytic reaction
I am working on gasification of biomass. In this, char (a solid phase) reacts with carbon dioxide (gas phase) to form carbon monoxide (gas phase). I need to model this system in a plug flow reactor, in which the solid char will be entering from one inlet with some velocity and a side injection of CO2 will be provided.
If anybody can help in this regard that would be a great help.
Thanks
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Problem with the convergence of Mooney Rivlin model
Dear all ; Im trying to model an hyperelastic tissue using Mooney Rivlin (MR) model in Comsol. When I use parameter values that satisfies the stability condition (below), the software never converges. This problem also occurs when I use two terms model. For all the examples that I could find and that work the C10 and C01 were positives. Did anyone face the same problem with Comsol? Stability conditions for MR: C10=-0.2948[MPa] // C10+C01>0 C01= 0.3179[MPa] C20=0.0300[MPa] /// C20+C02+C11>0 C11= 0.0715[MPa] C02 =-0.0973[MPa] /// C02<0 K = 0.4616[MPa] Regards
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Moving source and Time dependent geometry
I was trying to model a moving heat source over a plate. So the area around the source would keep on melting when it is moving. In each time step the material whose temperature is more than melting point would get removed in reality. How to go ahead with these kind of problems. I am able to model the moving source, but really dont know whether it considers latent heat , melting enthalpy etc. If the temp is more than melting point , will the system consider it as liquid? Aso how can we delete those meshes as the boundary conditions itself would change in each time steps.
Thanks a lot, Stay safe
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Surface Plot vs. Volume Plot
Hello,
For my simulation I would like to plot the Von Mises stress of a domain in a 3D Plot Group. However, I get different results if I use a Surface or a Volume within the 3D Plot Group. The stress values are substantially lower when I use a Volume plot. Does anyone know why this is the case? And which one should I use for my Von Mises stress analysis?
Thank you very much!
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Hello
I have version 5.4 and it doesn't have an induction heating in the heat transfer physics. Is there an add-on package for the induction heating physics?, and how can I get it ?
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Importing a complex geometry of a fault into the 3D geological model
Hello,
I am struggling with importing complex geometries of fault systems into my 3D geological model in COMSOL. I have tried many techniques and all of them seem to fail. See the description below:
1) I tried to include faults with a .dxf file and the fault geometry is nicely imported, however it seems to be weirdly compartmentalized and rather too complex (see picture). I am not able to merge this geometry into one surface.
2) I tried to import it as a polygon (just using the boundary lines of the fault) with a closed curve. Polygons are nicely imported, however i am unable to create solid or surface out of it (i get a message that output object is empty) (see picture).
3) I tried to import it using the interpolation function. It seems to import well the geometry, but as the geometry is pretty complex, i am left out with weirdly quazi-horizontal planes on the top and the bottom of the fault (see pictures), which i cannot remove as the surface is not 100% flat.
Does anybody have similar issue? I would very much appreciate some help and some suggestions how I can implement faults into my 3D geological model. See pictures below.
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Livelink for Matlab error
Hi All,
How do you extract the results in Livelink with Matlab. I can use mphglobal on the tuning fork example but get an error when I try it on a plasma example
I get an error when I use
mphglobal(model,'plas.ne')
Any help with the commands would be greatly appreciated.
Kind regards
Sinéad
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Make 1D simulation visible in 3D
Hi guys, I'm pretty sure, that this is possible, but I don't know, how to do it. So, my problem uses a cylinder as geometry. However, due to symmetry, I only want to do a 1D simulation to reduce computational costs. This 1D line would be basically the diameter of the cylinder. The simulation yields me a stress distribution over this line, but I'd like to make it visible on the whole cross-section of my cylinder, meaning I need to rotate my results of the 1D line around its centre. How do you do that?
Thanks in advance.
Simon
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Customize the physics equations
Hello everyone,
I am modeling a set of experiments in which I need to make some changes to the default equations and relatively new to COMSOL.
In the CFD module, what I would like to to do is to make one of the parameters a function of two-phase flow interface curvature.
Second, in the Structural Mechanics module, I would like to add an extra stress term to one of the either linear of nonlinear viscoelastic models. The extra stress can be a constant (which I think is easy) or a function of surface curvature.
I appreciate your helps.
Best,
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2d- isometric induction heating
I am a senior i working on simulating the response that a aluminum structure has to an external coil. i have built the assembly entirely in comsol and can run the simulation. when i create a new project using the inductive heating preset it loads in and after i build my objects it puts magnetic insulators on all the boundaries. the resulting simulation shows that the magnetic flux never leaves the coil, as if it was trapped inside. my question is how to get the field to actually leave the coil and influence inductive heating on the objects. attached is the .mph file, i had to clear the study though to make it small enough to attach.
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New to Comsol: Missing Magnetic Modules Under "AC/DC"
Hello!
I am new to Comsol and I am trying to simulate an electromagnet used in my research lab at school. I am trying to use the Magnetic Modules I see in videos, like "Magnetic Fields (mf)" but they are missing. I have an Academic License through my school, is that why these are missing? How can I access these modules?
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Numerical Wave Tank, Tw和ophase_Flow, Phase Field，the definition about Wave
Dear all, I am simulating a numerical wave tank in comsol, by using the twophase_flow, phase field method. I have found some examples in comsol, I feel confused that how can I make the waveform in 3 dimensional model. The result that I need to make is the uploaded picture. Maybe the Walls in Laminar Flow , or the interior wettet wall , or the other condition in the model builder. Hope you can share some idea with me.
Regards
Joey, Mai
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Can you give me some advice about piezoelectric materials?
Recently, I have been doing research on two-dimensional phonon crystal plate waves.I have some difficulties about how to set the boundary conditions of short-circuit of piezoelectric material.Thank you for reading and I hope I can receive your help!
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Reducing simulation time with two different time steps
Hello together,
I would like to simulate the temperature profile during laser drilling with an ultra short pulse laser. The problem is that the pulse duration is 800 fs, but the drilling takes 0.1 s. If my time step is greater than 1e-11 s, the pulse is not recognized by the software. If the time step is 1e-11s and the endtime is 0.1 s the simulation time is much too long.
Is there a possibility to shorten the simulation time, but the pulse is still detected?
Thanks for the help Best regards Marcel Jung
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Erosion rate
Can any one suggest me, How to find Erosion rate in Comsol model?
Which module need to be use?
Regards,
Vipul Rokad
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AC electrothermal flow pumping - ACET body force ?!!
I am simulating AC electrothermal effect for fluid mixing/pumping in simple design of chamber with 2 electrodes over silicon substrate. I used Electric current module + heat transfer in solids & fluid + laminar flow with electromagnetic heating Multiphysics to couple between EC and HT.
There is equation to be used as volume force that drag the fluid with permittivity and conductivity gradients resulting from AC applied signal. 2 Photos of equation is attached. no 1: Force equation represented by gradients of permittivity and conductivity no2: same equation but represented by change in Temperature gradient
I am stuck with writing any of the 2 equations in Comsol
What I know is that I can add all parts of equations in Variable section and define force in X and Y direction. I can define w, t stated in equation.
But I am not sure how (mathematically correct) to write full equation in Comsol ? Also, How E and nabla.T are defined ? nabla.sigma ? nabla.e ?
Someone can provide me with any ACET simulation files (not AC electroosmosis) with any design that include ACET body force added so I can see what I am missing ?
Hopefully someone with prior experience with ACET can enlighten me. Thanks in advance.
Here for more information https://www.comsol.com/paper/fast-biofluid-transport-of-high-conductive-liquids-using-ac-electrothermal-pheno-19635
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Wrench example question
HI all. My von Misses stress results when running the wrench simualtion are of the order of 10^-2 MPa. According to they "Introduction to Comsol" pdf and to the video herehttps://www.comsol.com/blogs/model-stresses-strains-comsol-multiphysics/ the stress should be of the order of 10^2 MPa. I am following the instructions to the letter and I tried building the model twice, same results.
Any idea what can be wrong? Has anyone faced the same issue?
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POINT EVALUATION (3d model)
Hello
I've done some velocity profiles in comsol 5.5 by using 3D cut line option. I want to know exact values of velocity along this cut line on several points. Let's say, some points following Cut Line, equidistantly spaced one from the one, for example a step of 5 cm.
By using Cut point option, then Derived values ----> Point Evaluation, it's possible to read specif values, but it takes so much times coz I'm obliged to do it one by one. I want this to be more automatic, I mean, by defining a step and be able to generate several cut points and evaluate them. I've tried with Array 1D option but it didn't work.
I've read this post and this one, but a exact solution wasn't provided. You can read them if you don't understand my explication of the problem
Maybe someone knows how to overcome this issue??
Thanks, Jhoan
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Can you give me some advice about Phonon crystal plate wave?
Recently, I am doing research on two-dimensional phononic crystal plate waves. I would like to know how to add only symmetric Lamb waves to the model to study the mode of S0 Lamb waves.
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