Rotordynamics, eigenvalues and frequency domain
Hi everybody, I have two questions about rotordynamics modelling. First of all, I'm modelling a rotor using a parametric sweep on angular velocity to find its eigenvalues. After that I would like to...
View Articlemode analysis, not getting the right neff
Hi: I am solving one file using Comsol 3.5a but I am getting neff to be 3.8. I am supposed to get it 3.88. Can anyone check why my neff does not go higher?. I have been trying for days and the best...
View ArticleHelp for Modeling Transmission and Reflectance of Light for a Stacked Layer...
I am an undergraduate student at University of Maryland, College Park. I am in a capstone research group, where we are designing a smart window device that consists of stacked layers enclosed in glass....
View Articlelinear system Solvers
Hi all, Basic question about solvers in comsol, does anybody know that what is the difference between direct solvers: 1) UMFPACK 2)SPOOLES 3)PARADISO 4)TAUCS I tried to read manual, but it seems vague...
View ArticleCOMSOL 4.0a : how to set maximum Java heap size??
Hi, I have problem to set comsol java heap. In v3.5a, I know I can modify java heap in comsol.opts. But in v4.0a, I can't find the comsol.opts, and I have no idea about setting the java heap. Please...
View ArticleViewing the whole equation system
Hello, is it somehow possible to take a look at the whole equation system, COMSOL has built, after it was solved? Thanks is advance.
View ArticleError: Failed to find time step so that given tolerances are satisfied
Error: Failed to find time step so that given tolerances are satisfied This is the error that Generalized-alpha gives. I think the BDF solver in similar cases gives the error"Cannot meet error...
View Articleauxiliary sweep
Hello everyone, I am simulating a reacting flow with a rather fast reaction. This problem does not converge, and I found out that I should try an auxiliary sweep with a parameter in front of the...
View ArticleSimulation time does not scale with processor
Hello all, Just as a preface, I do not have significant experience with Comsol in general, and the bulk of my manipulations are occurring within Matlab, but my question is of a general sort. I am...
View ArticleElectrostatics module doesnt work
Hello , I am trying to simulate Sharland et al's paper with 6 species corrosion process. After long weeks of attempts I have used constraints to enforce equilibrium constraints. Please find the...
View Articleelement order and convergence
I have a FSI problem that converges when I use first order elements for pressure and velocity and second order for displacements. But I am not happy with the results I am seeing. Hence I changed the...
View ArticleModeling a droplet formation
Hello, I am currently trying to model in 3D droplet formation such as T-junction. Attached file is my model. This model was simplified to calculate my comuputer. I want to calculate large model if...
View Articleperiodic function - picewise works, analytic doesn't
Hey, I’m fairly new to COMSOL and trying to use the Electric Currents and Heat Transfer Interface to simulate the heating process caused by an applied voltage in a solid. If I implement the applied...
View ArticleHow to implement the Beer-Lambert absorption law when ablating a solid.
Hi, I have a model which I am heating with a laser heat source. The laser is absorbed in the solid according to Beer's law, that is the intensity of the radiation exponentially decays with path length,...
View ArticleGeometry Parametric sweep
Hello, I want to run a geometry parametric sweep. Consider the following geometry sweep parameters: H range(20[mm],10[mm],60[mm]) Z range(0[mm],10[mm],20[mm]+H) The idea is that Z maximum value is...
View Articletime dependent study for sinusoidal wave
Dear all, I'm trying to simulate my module in 2D axis of COMSOL version 4.3 in joule heating physics with sinusoidal input voltage of { V0*sin(2*pi*50*t)} and for the frequency of 50 Hz it will takes...
View ArticleHow to solve the shutdown problem due to "flmklblas.DLL"?
I was running a parametric sweep model with direct solver, and my COMSOL 4.1 keeps shutting down when it goes about 60% of the process. The windows 7 logo says the error is due to "flmklblas.DLL". Does...
View ArticleConvergence problem ( PID heater controller)
Hi, I have a problem with the convergence of my model. I have this message d'error "" there are 876 degrees of freedom returning NaN / Inf in the matrix rows for the variable comp1.T. the coordinates...
View ArticleHow to solve the shutdown problem due to "flmklblas.DLL"?
Dear Ivar Kjelberg, Hi! My name is Shiyi Wang, a PhD student majored in Electro-optics. Your clear response and kind help impress me a lot when I check the solutions on the discussion forum. If...
View ArticleFailed to find a solution
Hello I am a new user, and I am very impressed, Comsol is perfectly simulated in chemical reactor design And when I began using of Comsol I have some problems with it. And I have a set of PDE's in...
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