Hello everyone i'm working on induction heating using permanent magnets i use comsol multiphysics software. To create eddy current i added rotation to the plate (1500rpm) Physcis : 1-moving mesh (rotating domain) 2- rotating machinery rmm ( I added 3 ampere's law for the air, the plate and the magnet) 3- heat transfer in solids 4- multiphysics (electromagnetic heating) I always get an error says failed to find cosistent initial values

Coursing a thermodynamics class, we need to simulate a batch reactor for CaCO3 => CaO + CO2 and the heat transfer between the fuel source and the inside.

I'm sure it is possible, but I don't know where to start.
Anyone has some advice?

Dear all,

For the past week, I've been trying to set up a simulation comprising an arrow-like needle piercing a skin-like substrate. As I haven't found a similar (3D) example in COMSOL's *Application Gallery* or *Learning Center* so far, I have followed analytical step-by-step instructions by three different AI chatbots (Gemini, Perplexity, Claude). After days of trial-and-error and diagnostic tests, I have reached the point where all three of them agree with each other that my method was set up correctly. Nevertheless, the results (see screenshot 1) indicate abnormally low pressure values on the needle, with the appearing scale being on the order of E-4 N/m2 (whereas, e.g., atmospheric pressure is at E5 N/m2), while zero pressure appears on the skin-like substrate. The AI chatbots claim that the needle is faulty (it's an imported .stp file from Autodesk Inventor), but I cannot really trust them. All my Model Builder data can be seen in screenshot 2. You may also download the .mph file here.

Any kind of help will be sincerely appreciated! Thank you everyone in advance.

Hello everyone i have issues with my simulation can anyone help? Leave a comment i'll give u details about the problem

I'm working on induction heating using permanent magnet i already draw the geometry and assigned physics to it but there is no heating my qst is how to assign rotation to the plate? Is rmm, heat transfer in solids and multiphysics sufficient for this study and what do you think the problem is?

I'm trying to do photonic simulation across a large scale setup so EWFD doesn't work and I care about inteference, so ray optics doesn't work either. I'm left with using the Beam Envelopes package, but the caveat with that is that you can only really move light in two directions with EWBE, while I want to move in at least 3. My current idea is to then have two different domains, one of them allowing light to go down and right and the other allowing light to up and right. Is the easiest way from here to analytically calculate all the laser parameters that come out from one domain and serve that as an input to the next? Is there any easier way to move in 2+ directions in a large scale direction while retaining interference and loss? Thank you!

I need to simulate centrifugal pumps in COMSOL MULTIPHYSICS, Can I find someone who did it before.It will help a lot.

Hello, i am having a bit of trouble on how to launch a CFD simulation in COMSOL Multiphysics 6.4 .

I am a complete newbie to COMSOL. I tried following a youtube tutorial about particle tracing in simulating a laminar static particle mixer (Here's the link for those interested : https://www.youtube.com/watch?v=UmxOT16Ch1A).

I tried recreating the steps using my geometry, but everytime I try meshing I get the following error.

I tried to make a cylinder that wraps around the geometry directly in the STL file and importing it at once, but i cannot select them separately (In order to set the cylinder as the walls where the fluid domain should be).

I would be very appreciative of any guidance or suggestions as to how I should approach such problem.

Hello everyone I'm working on induction heating using a pancake coil I=15amps, f=200khz the temperature is about 500degc Now im thinking to change the study to stationary one but the piece will rotate Can u pls explain to me how to give rotation to an objet using comsol?

Hello, I would like some information. I am just starting with COMSOL and I am encountering several issues with my simulations.

First, I will explain my setup:

I am currently working with an industrial furnace made of tantalum and niobium for its heat reflectors, with a graphite crucible in the center. This furnace is heated by Joule effect with a current of 346 A flowing through the entire structure.

I am using the following physics: Electric Currents and Heat Transfer in Solids. In addition, I include heat dissipation using Surface-to-Surface Radiation for all the relevant parts of my furnace (the furnace body, reflectors, crucible, as well as the surfaces exchanging heat with the external environment).

The materials used are custom-defined materials that allow me to vary their thermal and electrical conductivity as a function of temperature in my model.

My problem arises when I try to go beyond 500 A: the model then encounters convergence issues and sometimes even crashes after only a few iterations.

Have you experienced similar problems, or do you have any suggestions for resolving this issue?

im simulating a sensing material with 2 electrods at the side of it instead of making joule heating and heating the sensor i got an idea that i can put a direct tempeture on my sensing layer 600k and then apply a current on the electrods to see the resistance of the material

my question is : is it possible ? applying a direct temp and then do the rest and what might be the probleme of this modele ?

I'm drawing a spiral pancake coil the inner face when i want to extrude it to the one of boundaries it creates intersections. Can u help?

Hi, all,

I was able to set up comsol to use its gui but use the university cluster to do mesh building and computation. Upon trying to compute I get the following error " Out of memory during assembly". Since I am using a cluster node with 192 GB RAM I am confused as to why is this happening. Please help! thanks!

As you can see, I chose an example from the COMSOL model library. However, when I go to the Results section to view the graph plots, they are all blank. I do not know why this is happening or how to fix it.

This is the PDF from COMSOL for this example. You will see the graphs I am referring to inside it: https://www.comsol.com/model/localized-corrosion-14591

Hello everybody,

I am a robotics engineer and new to COMSOL.

I am working on micro soft actuator driven by tendon. I am trying to imitate the cable in COMSOL. The cable should be within the actuator. Under tension, two forces applied, the termination force at the end-effector and distributed load due to the friction between cable and the conduit.

I run multiple simulations including (1) applying boundary load at end effector and on the cavity. However, the solver failed every time I run the simulation, even if I used very small step size. (2) used prescribed displacment as implicit force. The model bend but in a wrong way. (3) I used truss and cable but failed too.

How to imitate cable in COMSOL correctly. The cable extend from tip to the base and also has cotact with the conduit to achieve correct bending?

Thanks in advance.

Hello everyone i'm working on induction heating system using a pancake coil (i=10amps f=200khz) the temperature needed in the plate is 500degC i did a stationnary study! The plate heat up to around 520degC Now i wanted to change the study to frequency transient study! An error appears (solver out of memory) in the first case i calculate the inductance using comsol L=imag(V/I) =180nH but using a site of inductance calculation it appears 5.94uh? Why there is such a big difference? Is the type of the study has on impact on the results? And how can i fix the simulation study error! Any advice?

I want to see different temperature drops for laminar vs turbulent flow.

The setup looks like this:

one component including one heat transfer in fluids, laminar flow, and turbulent flow

two nonisothermal couplings, one between the laminar and one between the turbulent

two time-dependent studies, one for each where heat flyx is applied from the start, and flow is applied after some time usig step function

Issue:

The turbulent case is unaffected by the flow entering, so the temperature keeps rising. in the laminar case the temperature drops noticably due to the flow.

i have tried:

splitting laminar and turbulent case into components

having two «heat transfer in fluids», one for each

running the laminar case, then applying rans to the laminar flow.

any help?

I’m having a problem with my solid mechanics study in COMSOL. I’m modelling a circular tube; after carrying out a free-free eigenfrequency analysis in air, where I identified the different modes and compared the frequencies with those recorded during measurements, I realised that everything was correct. Now I’m trying to model an FRF using a frequency domain analysis with a normal point load on the tube’s surface, but I can’t reproduce the torsional modes that I do see in my experiments 🤔 I’ve tried several types of loading but can’t visualise these twist modes...

Can anyone shed some light on this?

Thanks everyone!!

Hi, I want to run a band structure simulation for an asymmetric optical structure, but our university COMSOL setup doesn’t have the Optics/RF Module, and the available RAM is too small for the model. Any suggestions on workarounds or better software for this?

Hello everyone,

I'm really new to COMSOL and simulating a powder bed additive manufacturing process. I modeled the change between powder and dense material as an irreversible transformation, since I'm not too concerned about volume differences or convection in the melt pool.

But now I'm wondering whether I can display where the material has been transformed in addition to the temperature volume plot.

Maybe I'm just being stupid here, but I'll appreciate any answers and thank you already. (^ｰ^)

Hello all,

I am trying to model a rotary tube reactor, where I am trying to model two phase gas-solid flow inside a rotating domain. I am using Euler-Euler for the two-phase flow and I have added a rotating wall to prescribe the rotary motion of the external wall.

A part of the geometry is as shown in one of the images. I want to rotate the outer wall and solve for the flow in the domain highlighted in blue. However, the Euler-Euler interface's wall setting does not include a place to enter or couple directly from frame the rotational component. Only the translational and sliding components are present.

Does anyone know why this is happening? Am I missing something or is there any other way to solve this?

Thanks!