Comsol Definition and 223 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...

I would like to solve a coupled system of two PDEs using Comsol for the following geometry: Equation 1 (valid for 0⩽Z⩽bm): The initial and boundary conditions are: Tm(r,t→0)=20 Tm(r→rw,t)=70 Tm(r→∞,t)=20 However, for bm⩽Z⩽bm+b2, the equation to solve is: With the following initial and...

Hello, I followed the following example for modeling the induced current from a moving magnet in a coil https://www.comsol.com/support/learning-center/article/Modeling-Induced-Currents-from-Moving-a-Magnet-Through-a-Coil-9871/112 If I have a bigger model with a bigger displacement of the...

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...

I am trying to simulate a Thick-GEM detector in Garfield++. In order to do so, I need information of the field maps which I generate using COMSOL. I've already extracted the mesh data and the potential data. For the initialise function, I need another file that gives dielectric information of...

Hi. I am studying the effect of plasmonic nanoparticles on solar cells. Is there a way to calculate absorption efficiency in different layers of tandem solar cells in COMSOL Multiphysics.

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...

I really don’t understand the advantage of 3 phase flow, phase field module in comsol. For example, if I want to simulate a compound droplet inside a fluid. Can’t I use the moving mesh with 2 fluid-fluid interface? If yes. When should I use the 3-phase flow, phase field simulation?

I have been simulating a 2D particle/droplet motion inside a larger emulsion using Comsol where the flow field inside the emulsion is calculated from a moving mesh laminar flow simulation. my problem is: I always get an undefined variable error " Variable: comp1.w" however this variable is the...

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

Hello What is Metal and PML boundry condition in Comsol? How can i specify metals and insulators ?

Hi All How can i simulate Graphene in Comsol? I am using semiconductor module . I s it correct to use Drude model? Drude model is in RF module but my simulation should be run in semiconductor module. How about Kubo formula?(for optics application or no?)

Hi, I'm trying to study single sheet testers. Anyone could provide with a sample model on comsol for me to get started with? Any help is greatly appreciated.

Consider the weak form Input this equation in COMSOL Homework EquationsThe Attempt at a Solution test(ux) -exp(x)*test(u)

Hi, anyone using COMSOL? I'm new to this program and I'm trying to get a plot of the pressure distribution on a cut-plane of a cube. I have applied a boundary load of 4 MPa to the upper surface of the cube and fixed constraint to the bottom surface of the cube. Now, as a check, when plotting...

I am doing the dynamic process of a water droplet impinging onto a wax substrate in COMSOL, using the Phase Field method for tracking the free surface. I am able to do the simulation for Static Contact Angle(SCA) i.e i am imposing a fixed contact angle throughout the time step in wetted wall...

Hello everyone, In the COMSOL v5.1 doc i haven't found the mathematical description on how does the automatic geometry analysis or the curvilinear coordinates adaptive method (it is mentioned that they are similar) works. It would be convenient to have an idea about how does the Ecoil vector...

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...

I am new to COMSOL and I want to model fluid flow in stress field. As starting point I want a simple 2D box having a fracture from right to left while pressure gradient vertically. I want to know the threshold value of that pressure from top which allows flow of fluid in fracture. Can anyone...

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...

Does anyone here have experience with COMSOL? I want to model a system where i have a fluidic channel containing warm fluid running through a block and I want to analyze the heat transfer from the channel into the block . To establish the warm fluid I put an initial temperature condition at...