How can i generated DEP force and electric field between two electrode using...
hi, How can i generated DEP force and electric field between two electrode using comsol 4.4?? i already done my design (electrode desing) in 2D...which module should i use electrostatic(es) or electric...
View ArticleSlug flow of Two immsible liquids
Hello, I would like to generate a slug flow in a micro-channel (as shown in the attached image). I have started my model by using the Droplet Breakup Model but I noticed that the droplets started to...
View ArticleVery Urgent: Piezoelectric Filter Lumped Port Problem
Hi I am trying to find the s parameters of a mechanically coupled piezoelectric filter with lumped port. But even though I have defined the perfect conductor, I get this error: Errors during...
View ArticleVery Urgent: Piezoelectric Filter Lumped Port Problem
Hi I am trying to find the s parameters of a mechanically coupled piezoelectric filter with lumped port. But even though I have defined the perfect conductor, I get this error: Errors during...
View ArticleHow to couple multiple physics
Hello, I have a big issue when I try to model harmonic generation in plasmonic nanoantennas with the RF module. But this can be a general issue when you must couple multiple physics. I am simulating...
View ArticleChange boundary conditions during a heating process
Hello, In an heating simulation, I would like to change a boundary condition during the simulation. I would to impose on this boundary: 1. a heating condition during 600 min 2. an tempering condition...
View ArticleProblem with periodic boundary condition
Hi, i have a problem that i don't really understand. I made some simulation of a square impedance tube to compute sound absorption coefficient. The mode works very well. when i apply a periodic...
View ArticleResolve error; MUMPS allocation factor increased
Hello everyone On running a time dependent study I get an error that "MUMPS allocation factor increased to 2.0736." I know that this error can results due to incorrect boundary conditions but I am feel...
View ArticleRAM using
Hello everyone! I couldn't find the answer on the forum. I have 32 Gb RAM memory (Win8 x64). The Mesh of 3D model consists of ~300 000 cells. When calculation of a task is performed, memory consumption...
View ArticleOut of memory during assembly BUT the mesh number is just 3608
My model is 3D using Heat transfer in porous media, and the total mesh number is only 3608, but the error "out of memory during assembly" still occurred, why? Model file was attached. My operation...
View Articlesolution can not be converged
Dear Everyone, I built 2d axisymmetric model, which consist two iron cores(Cobalt steel vacoflux 50) and two coils(with 5A, 5000turns), I applied HB curve to iron cores. I want to see the magnetic...
View ArticleHow to give maximum and minimum limit to a variable in user defind function...
I am trying to give an user defined function for viscosity which is a function of pressure and shear rate. I want to take the value of pressure to be the pressure calculated by comsol but then i do not...
View ArticleBoundary Stress
Dear all, i have a problem. I try to simulate a fluid flow effected by a boundary stress on a key hole. See attached mph-file. With a very big mesh, comsol solve the problem. But with a smaller mesh,...
View ArticleElectrical Asynchronous Machine, rotor short -circuit in 2D?, rotation via...
Hello, I am trying to simulate an 4pole (q=3) asynchronous machine with the .rmm physics module in 2D with COMSOL 4.1. So far I am able to excitate the coils with a Voltage through the "Electric...
View ArticleAcoustics - Large models convergence
Hi, I'm driving crazy about this subject. I think don't know many things about this model, but regardless how mesh, solver configuration (multigrid, iterative, direct, etc.) or any other thing I change...
View ArticleIsolating components in study steps (and solutions)
Can someone help me understand why even though I tell all my study steps under one study to use only a single physics interface the solver still tries to find dependent values for variables under the...
View ArticleMass flow rate vs temperature.
Hi, I used Comsol to model a really simple problem. A pipe with 50mm diameter and 25m long with an inlet temperature of 20°C and 0.5kg/s of mass flow rate. Also, the pipe´s wall temperature was 150°C....
View ArticleOptimisation of processing parameters in laser sintering of metal/alloy powders
Hi everyone, I am new to COMSOL Multiphysics.. Can anyone help me in simulating selective laser melting(SLM)/direct metal laser sintering(DMLS) of metal/alloy powder media in layer-by-layer fashion? IN...
View ArticleLimiting the Parametric Sweep study step to a specific step(s) in the study.
I'm doing a small signal analysis (stationary, freq-perturbation) and I want to run a parametric sweep (on geometry) for the stationary step only. I can't seem to figure out how to isolate this within...
View ArticleRotation of 3D geometry taking too long time to compute
I am using the rotating machinery laminar flow physics. I am trying to solve with time dependent study. Every time after computing 7% or 4% it hangs up and continues doing iterations upto 2000 and...
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