Invalid field variable in property Llimitfivar
Hi, I'm new to Comsol 5.1 version and i have a problem with my simulation. Does anybody know what "Llimitfivar" is? I'm searching for it's meaning for some time and i can't find anything. I have no...
View ArticleSolving differential equations (Diffusion and Reaction) using the Mathematics...
Hi all I'm trying to learn a bit of mathematical modeling of chemical reactions whilst combining it with the Mathematics physics of COMSOL. I am however, in a bit of trouble and I hope you can help me...
View ArticleApplying DC voltage to get current distribution in a biotissue
Hi, I am looking for some help to make a model which will so current density distribution in a biotissue after applying dc voltage. Thanks in advance.
View ArticleElectric field for concentric spheres with a current source
i am trying to compute electric field and potential for a four concentric spheres with different connectivity. inject a constant 1 [A] current from one cylinder (source) and eject from other one(sink)....
View Articlefrequency-transient equavalent simulation method
Hi, I am wondering whether it is possible to do a simualtion by taking a method which is equavalent to the frequency-transient solver. For example, i'd like to perform a electromagnetic heating by...
View ArticleFluid-Structure Interaction Particle blockage
Hello! Have a nice day! I am solving one problem in COMSOL Multiphysics Fluid-Structure Interaction model (FSI) at the moment. I need to take results in which particles must blockage porous media. I...
View Articlesetting logging time step size and time step taken by solver
I am using Comsol to model a problem with time dependent boudary conditions. The boundary conditions vary with high frequency, so I set the maximum time step very small, to 0.001 seconds. However, I...
View ArticleTime dependent Optimization
Hi all, I have already modelled the time dependent simulation for porous media. I have two equation variables. !) for inlet in to CFD (time dependent equation with two time parameters.) 2) an another...
View ArticlePiezoresistive Beam
Does anyone here uses Piezoresitive module for modeling a piezoresistive beam? Or has any example which s/he can send for me? I am really confused about the results and I need to take a look at one...
View ArticlePML error
Hi all, Can someone point me what I do wrong? I tried to repeat Scattering from plasmonic nanosphere model, so I have Au sphere + Air domain (sphere) +PML/ABC domain (sphere). When I defining PML as...
View ArticleHow to specify infinite line currents in a 3D Magnetic Field model?
I have a Magnetic Fields model where an infinite line current induces current in a nearby passive loop. I have attached a toy model that illustrates this scenario, and image of the geometry. I define...
View ArticleError with high reaction heat
Hello, I have a problem with solving the heat balance for high reaction heat (-165 KJ/mol, math interface). If I reduce the heat production with factor 100, the simulation works, otherwise I get an...
View ArticleMoving solid particles in a laminar flow
Hello, I want to simulate moving solid particles in a laminar flow with some obstacles (vertical columns) in their way. What I want to see is that how they get trapped in the gaps between the columns...
View ArticleUsing values from the "Equation view" section as input in a Coupled Multi...
Dear All, I am doing a Multiphysics modelling on the formation of an ultrasonic standing wave field that is used to separate suspended particles in a continuous medium (a colloid). As you can see from...
View ArticleRequired power for an electronic system
Hi, I have successfully built and simulate a system in the AC/DC module. Now I want to know the power input required required to sustain the condition/reach that voltage. Is there a way I can find it...
View ArticleODE simulates magnetic hysteresis but fails to find consistent initial values
Hi During my test of COMSOL 5.2, I have confronted with a problem when simulating the hysteresis effect using ODE. I am now simulating the hysteresis effect of actuator based on a smart magnetic...
View ArticleParameter estimation
Hello, I want to determine one parameter k1, which is used over the entire domain. However, objective function values should be compared only at a boundary. According to the Optimization user manual, I...
View ArticleTime-stepping
Hi, I would like to run some simulations which use an exponential time step, and I have figured out how to set that in my "range" of solutions shown, but I was also wondering if there was a way to have...
View ArticleStiffness/Residual Vector Error - NaN/Inf findings
Hi, I am especially writing this, because there is no specific explanation I found online. I checked the BCs and other variables, but could not find any mistakes. I am working on a semiconductor device...
View ArticleHeat Generation in a Disc Brake
Hi everyone, I've got simply problem with few questions. I'm working at a heat generation in a disc brake, just like the one from Application Gallery, but more difficult, with a 3d model synchronized...
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