Questions about defining different variable in different equation in subdomain
Hi, I am now using PDE model to slove Laplace and Poisson equations. My model has three domains. I have used V as the variable in Laplace equation in two dielectric domains outside and V0 in Poisson...
View Articlephotonic crystal fiber (Higher order modes)
Hi, I have designed few photonic crystal fibers using COMSOL software. How would i determine the higher order modes using this software? Thanks in advance.
View ArticleJava API SwingGraphicsPanel
Hey there, i am currently working on a GUI for the COMSOL results using the Java API. Now i have a very annoying problem. I use the class SwingGraphicsPanel to display the results but sometimes it...
View Article2D->3D
Hi, I built a working 2D model of a redox flow battery and now I am trying to convert this model into 3D. I used the same BCs and the same initial values but it does not converge. I get the error...
View Article2D simulation with floating electrode
I am fairly new to COMSOL and was wondering of anyone knows how to correctly define a floating electrode in a 2D simulation? I have some strange results from my simulation. I have two concentric...
View Articlehorizontal stress only shows in the top layer
hi i'm simulating a road using the elastic model. the road has 3 layers (asphalt, foundation, soil) with different moduli. when I apply the loads of the wheels, I can clearly see how the vertical...
View ArticleModeling Multi-turn circular coil
Hi, I would like to model a multi-turn circular coil as shown in the picture. However, i am confused with the modeling procedure. My objective is to perform RF coil simulating in Comsol. As that i am...
View ArticleHow to become expert in COMSOL
Hi Guys, I am working on COMSOL 4.3a from last three months but still facing some difficulties to become expert in its use. I am not from Engineering background so don't have any experience about...
View ArticleConvergence problem with Comsol 4.3b
Hi Everyone When I run the model in the 4.3a, it can work very well. The convergence firstly is about 1e4 to 1e5. When the comsol software is updated from 4.3a to 4.3b, the convergence becomes 8e8 and...
View ArticleFor a 3D geometry, is there anyway to get data from one of the plane without...
I have a 3D cylinder, is there anyway for me to get the information on the top surface and feed the information back to my simulation? is the boundary probe the only way? Or is there any way I can say...
View ArticleLift and drag force
Hi all, I am simulating a 2D, turbulent flow over the airfoil. In the post-processing level, I do not know how to get lift and drag forces applying on the airfoil. To compute reaction forces, As far as...
View ArticleInitial Values of a Simulation
Hello, I'm trying to use in a time dependent simulation as initial values part of the values I have solved in a previous simulation. I want to use part of the solution, and give other values different...
View ArticleHow to unite objects with assembly mode?
Hi everyone, I'm modelling coils using the Multi-Turn Coil Domain, and I'm having trouble getting the magnetic fields to work when I finalize the geometry with an assembly (I need to use assembly mode...
View Articlehow to show the error curve
Hi All, Normally there is an error curve to show the convegence speed when running a case. However, I closed some windon in Graphic and this error curve is not shown. Wihout this curve, I am not able...
View ArticleTime integration of a variable over the domain
Hi, I am solving a periodic fluid flow problem over a 2D domain. I need to find the time averaging of the term u*ux+u*vy at each point on the domain. I tried defining a global ODE but it gave an error...
View Articlesegregated vs fully coupled solver in comsol
Hi All, I have compared these two solvers for a heat transfer case with surface-to-surface radiation. Acutually simulation results, i.e., temperature distribution in the domain, are quite different....
View Article3D Wall Shear Stress
I realise this may have been asked before, but I'm running a CFD simulation of blood flow through a 3D cerebral aneurysm model. Initially, I have a laminar flow study in which I would like to visualise...
View ArticleStep function
Very simple question, but I can't find out how to do it. I have a external temperature, "Temperature 1", which is 100 C. After 330 seconds I would like it to drop 80 degrees to 20 degrees. I should be...
View ArticleMEMS
How can i compute the displacement due to gravity in a silicon proof mass in accelerometer and therefore i need to compute the change in capacitance in the accelerometer. My basic question is how do i...
View ArticlePartial integration in full integration
Hello all, I am trying to calculate the induced voltage in a coil in the time domain, the formula is: V=int(part(A)/part(t)dl) i hope you get the idea, that is a line integral for one filament of a...
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