Comsol Definition and 175 Threads

I happen to be modelling PEMFC and accounted for various transport equation including mass, heat, species and charge. I was able to validate my stationary model based on a published reference. In validating its voltage dynamic response, I was expecting at a potentiometric conditions that an...

There is heating of the surface of the material using an electron beam. It is necessary to calculate how much heat will be released and build a graph of dependence. Please tell me how this can be done, which modules in COMSOL can be used?Thank you!

The InSb sample (parameters 10x10x0.5 mm) is glued with silver glue to a cooled copper table. Liquid nitrogen passes through the table. While the model is at a temperature of 300 K and at a normal pressure of 1 bar. The sample is affected by a beam of electrons, which causes the surface to heat...

Hi, I am willing to simulate a 3D ferrite bar transmitter and reciever where coupling coefficient k and Bt magnetic flux density on the each side uses the finite element method for solving partial differential equations. The Magnetic Fields module has equation (jωσ − ω2ε0εr)A + ∇ × H = Je...

in terms of accuracy, solvers etc.

It is a sensor with a fixed surface and a prescribed displacement on the opposite To remove this message error, I have tried to Increase iterations Refined mesh Applied parametric studies And some other ideas from forums However it still cannot be solved It also has a warning of MUMPS out...

I have been experimenting in producing some strain to this object. However, after applying a prescribed displacement and setting it to a certain value, it does not exceed 2.18[um] no matter any extreme value for the prescribed displacement. I have also experimented with an applied force as well...

Hello, I am trying to learn comsol but I couldn't find how to apply the pressure that changes respect to time and space. I have pressure function from articles that I read but couldn't implemented on comsol, and in most studies people make the simulation with Abaqus software so I am not sure...

At the risk of waiting hours on simulations of a sensor, I was wondering if I could use infinite element domain on COMSOL to simplify it. The first image consists of what I would like to simulate but found out that the simulation time is a huge factor as I have a lot to simulations to conduct...

Hello, I have used an edge current of 10 A through a 0,45 cm (lenght) wire inside an air sphere. The thing is that, according with Ampere law, the magnetic field (B) produced at a 1 mm of distance from the wire shall be 0,002 T, and I am obtaining much higher values in this simulation (around...

Hello folks, I want to simulate a 2D heat transfer process in the subsurface on a region which is infinite on the r-direction. So, as you know, the very basic way to model this is to draw a geometry that is very long in the r direction. I have done this, and the results that I obtain is correct...

Hi everyone, Has anyone tried to model Radiative Transfer equation on comsol? I am stuck at defining the integral term which includes scattering. Also , how do i make my functions have 3 variable dependence as RTE has dependence on position, time and direction vector

So I am currently trying to model a MAGLEV train using COMSOL (high school research project). My project uses AC and DC motors as alternatives to the current maglev infrastructure and transportation. I first created a prototype through CAD Onshape, then created it in real life and applied my DC...

I am new to Comsol. I want to draw my model which is a Tesla valve. The geometry is little complicated and I don't know how to draw a semi-circle tangent to a line. Is it possible? I draw it in Solidworks and imported it into Comsol but it gives error and I think it is better to draw inside...

COMSOL gives me the impression that it always gives unrealistic solutions in time domain for wave problems, say mechanical waves or simply solutions of a wave equation. In frequency domain, COMSOL works better for wave problems. Anybody agrees?

Do new versions show advantages in computing capability than old ones? For instance, could a solution not converged in an old version become converged in a new one?

Thanks in advance.

This figure shows 2 capacitor plates. Except the region in between the 2 plates, I want to set the others as infinite elements. How to 'stretch' the x and y directions in the infinite element settings?

How to visualize charge distributions in COMSOL, like showing + or - charges on a surface or a bulk in postprocessing?

In 2D modules, the 3rd direction isn't shown in model settings. What assumptions are made regarding electrostatics 2D modules? For example, how is a 2D Poisson's equation with point sources solved? Is it based on a 1/r potential or a log potential?

Hi I made a simulation (comsol) of a piece of aluminum wire (r=1mm h=10mm) excited by 1A DC inside a sphere (r=10mm) of air. Here are the 3D plots: Since I ever only have 'seen' E&M fields depicted in textbooks and never in real life, I'm a bit surprised by the simulation result, I would at...

Hi Y'all For the purpose of exploring COMSOL, I challenged my self to plot the E/M-fields of a piece of current carrying wire in 3D. It's quite a simple task to plot the fields inside the wire, but I fail when plotting the fields outside the wire. For plotting the outside fields I have...

hello, i have a problem in comsol multiphysics, i want to relate many terminals to each other to buid a current circuit in 2D geometry. I was thinking to simulate the capacity between winding wire of a coil. So, I have to choose boundary conditions in the winding wire which are Terminals and...

Hi. Can anyone help me to figure out how to run multiple studies in COMSOL? I want to first compute the displacement of a membrane using temperature load and then find the capacitance between two electrodes using electrostatics. The idea is that as the membrane moves upwards the capacitance will...

Hi there, I'm failing in simulating the fresnel equations in 2D with Comsol. As you can see in the model added to this post, the reflectance and transmission in the global plots both for TE-waves ("Port, senkrecht polarisiert", Plot "Reflektion und Transimission, senkrecht") and TM-waves...

Hello everyone, I am wondering how to model ambient air around a thermoelectric module in COMSOL. I am fairly new to the software and am doing undergraduate research revolved around it. Any help or pertinent examples would be appreciated. I can send/post screenshots and or .mph files if it would...

Can anyone know please know how can i impose the electrode surface potential to vary lineary and periodically with time as: E(t)= phimin+v*t for 0<=t<t0 phimax-v*(t-t0) for t0<=t<2*t0 with t0=(phimax-phimin)/v v=scan rate in V/s

hi i m looking if there a method to introduce a systema into COMSOL (like coaxila cable) and this systems excited by an external field

Hi, I'm a newbie at Comsol and want ask for guide how to fill something with fluid and make sphere rotate. My goal in creating system where one sphere contains second. Second sphere rotates on its axis. Volume between is filled with fluid. I understand how to create spheres, but couldn't...

Hello everyone, First of all I am new here~ Second, I would like to "prove" on COMSOL that soundwaves (sound vibration) can alter/reshape the fluid flow Can someone tell me the physics i should use as well as all the other parameters to make it work? if someone is more experience can they...

Hello I'm looking for a graphical software to simulate a gas sensor mechanism. I thought "comsol multiphysics" could help me to determine the sensing mechanism of semiconductor gas sensor , but I didn't find any thing about this. I would appreciate you If you recommend an appropriate application...

Hello to everyone, I've just started my PhD in Mechanical Engineering. And we've to buy a computing machine of high end to use ABAQUS and COMSOL software. Can anybody recommend the machines which can run these both software. P.S: We have to use Windows because there seems to be some graphics...

Hi Friends, I am trying to find variation in capacitance between two plates with applied body load. I defined an air box around the plates. Now I'm trying with electromechanics physics for applying body load and finding capacitance. I defined the two plates as linear elastic material. Applied...

Hi I am new to the forum, I am using darcy's equation to model a tumor - tissue medium. In the literature I found that K - Hydraulic conductivity is given by cm^2/(mmHg.s) But in comsol it's given by (m/s) Is there another term involved in this?

Hello! I'm not sure if this is the right forum for this topic, but my question is very general, not a textbook problem or something like that :) . I work in Comsol where I have imported the topography of mount St Helens and I simulate wind flow around the mountain (as laminar flow) and also...

hi im supposed to simulate a vcsel laser for my thesis i got problem in selecting physics.. i should check its heat transfer and threshold current but i don't know which physics should i choose ! does anyone know about vcsel's physical structure in Comsol ? by the way does anyone know that how...

Hi, I would kindly appreciate it if someone could help me with my simulation problem. I am trying to simulate dual porosity in coal and the interaction of coal matrix and fracture flow. The problem I'm having is I can't assign separate domains with different pressures for matrix and fracture in...

Dear all, I'm an electric engineer, and I usually work with software as Ansoft Maxwell, Matlab, Ansys, COMSOL... I need a PC for serious professional simulation, and I would like if someone can give me some tips of the characteristics I should ask for this purpose. I don't want to spend more...

Hi İ recently started working with Comsol and have a few basic queries. İ am using Comsol version 5. 1. İ am trying to use parametric sweep. So i used it once and saved the file. Now when i try to change the range of sweep it is giving me an error : "parameter list gives empty sweep". When i...

Hello,

Hi, I want to know what is the proper boundary condition in COMSOL RF module to study optical interactions, Scattering BC and PML? or what is the difference between them? also I want to know if the rules are different for application of these two BCs in far-field and near-fields studies...

I have a problem in modelling a magnetic field of permanent magnet on ansys and comsol .I'm very thankful to you if you guide me or provide me a tutorial .thank...

Hi, I'm doing a 1D thermal conduction simulation on Comsol Multiphysics 4.4 and my first component is vacuum. I did'nt found the vacuum in the material list. Should I create a new component with a null thermal conductivity ? Thanks

hello to every on i m trying to desalinate seawater with an ion exchange membrane. the initial voltage of my simulation is 5 volt and it increase to 7 and 9Volt when i insert that data to Comsol it doesn't work and give the below error...

Hello everybody, I am a newbie in Comsol and I would like your help regarding a problem I have. I am modeling the 3-layered human skin (epidermis, dermis, subcutaneous tissue) and I would like to know how the temperature of each layer is affected after laser irradiation on the top layer...

hi, can somebody pls help me with the model i have appended to this post? it is a simple thermal mechanical contact problem but i don't know what is wrong about it and why there is some errors in it after computing. thanks

Can I prevent setting up standing waves in my COMSOL model? I'm using integration over two opposing faces to get the pressure at the 'outlet' - but it seems that no matter what I do to prevent the standing waves, they won't go away. Any help would be great, Thanks

I have a model set up, that is a cuboid, with a membrane half-way along - a bit like an impedance tube setup. I've used Integration 1 & 2 with Explicit 1 & 2 to define an 'inlet' and 'outlet' at opposing faces of the tube. The Variables for the inlet and outlet are intop1(p0) and intop2(p)...