3.5a and 4.2
Hi to all, I am trying for the first time the new version of COMSOL, while until now i could work only on 3.5a. I have to do a multiphysics simulation including heat transfer and fluidodynamics. The...
View Articlemagnetic field intensity distribution
Hi, i have a pipe that consists of some stainless steel wires with a magnet out of the pipe and magnetic nanoparticles flow through the pipe. How can i simulate this system and the magnetic field...
View ArticlePID Controller Constraints
Hi all, I have implemented a PID temperature controller (based on Voltage control) into my model but I am having one issue with it when I change the setpoint temperature. I have the setpoint...
View Articlescrew movement using multibody dynamics
Hi, I modeled screw/nut assembly in SolidWorks and transfered to Comsol multi-body dynamics module. The goal is to keep the nut fixed and give one rotation to the screw to see it is advanced by 1...
View ArticleVariable modifications between solution iterations
I'm developing a transient model using the Livelink interface. The model first calculates an initial solution for the first time window, then I would like to modify the state variable values due to...
View ArticleHow to use Laminar Flow Pressure results in Solid Mechanics, help?
Hi, I need to use as an input in the Solid Mecanic module the Pressure results from Laminar Flow calculations. Can anyone explain me how to do this? thank you for yor answer. Best regards, Leonardo.
View ArticleGeneral Projection Bulk Temperature Example & Question
Dear all, The following model may prove useful to somebody (other than myself) who wishes to calculate the average of some scalar value as a function of axial distance. In this case it's the bulk fluid...
View ArticleHow to simulate the Surface roughness for a solid particle
I want to simulate how the liquid to wet solid particle by considering the capillary force and surface roughness. I have simulated the capillary force by level set. but for the surface roughness, I...
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 Articlefrequency domain using reduced basis (modal)
Hi all, I'm trying to make a frequency sweep on a (big) model of an acoustic cavity, with specified surface impedance as boundary conditions. If I use the "Frequency domain" study, everything goes...
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Re: problem in apply the numerical flux in PDE
Hello, (This discussion refers to paper in www.comsol.com/paper/3d-simula...ion-in-a-squid-giant-axon-7317) Perhaps I'm mistaken, but I think that there is an error in the paper. For me, it would be...
View ArticleThe affect of air flow on cantilever
I'm working on a project on COMSOL to study the affect of flow on cantilever, I used laminar flow and solid mechanics in my model. I drew the cantilever with fixed end in a box. two surfaces of the box...
View Articlejacobian error
Hi all, I am running more than one model in the same file, separately. I do it because in one model I need the results of another model. I tried to refer to a solution typing, for example mod1.mf.Bx....
View Articleacoustic pressure, frequency response on modal basis
Hi all, I am using Comsol 4.3a and I can't find what's wrong with my use of the frequency response study using reduced model. This is my second post on the subject, as the first one didn't attract much...
View Articlecoupling electromechanics with electrical circuitry
Hi, can some one help me please? I want to couple electromechanics with el. circuit to solve cantilever problems. And the problem is, I applied a button surface as a terminal for el. circuit and this...
View Articlemems based capacitive type humidity sensor
Hello I am working on capacitive type humidity sensor in which I've to model diffusion of humidity in polymide layer that will change the permittivity of polymide hence changing the capacitance between...
View ArticleFailed to evaluate variable Jacobian
Hi there, Im trying to simulate a 3 phase synchrone machine using Rotating MAchinary, Magentic and magnetic field The simulation model works but when I add the roating machinary and magnetic physics...
View ArticleFlow through a concentric annulus
Hi, I have some problems for the simulation of a simple flow trough a concentric annulus. I use an axisymmetric model in which only the annular duct is defined (the model is attached here). Then, for...
View ArticleCanceling a solve operation takes a LONG time. Why???
For some reason, canceling a solution process often takes a very long time with COMSOL (10's of minutes to hours). So what it happening that takes so much time to stop? I would think if you're just...
View ArticlePolar coordinate system to evaluate stresses in an axisym. problem
Hi, we have a hollow sphere under constant outer pressure which we reduced to an axisymmetric problem in Comsol. We want to evaluate stress normal and tangential to the surface! So we need a polar...
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