convert .m to .mph
Dear community, Here is a little tutorial about modifying a model in Matlab and send it back in Comsol. In my humble opinion, the Comsol 4.1 LiveLink for Matlab User's Guide is not that clear about...
View ArticleInterpolation Function Help
Good Morning, I'm having trouble using COMSOL's interpolation function, and I was hoping someone might be able to help. I'm trying to load data from a tab-delimited text file. I've followed the...
View ArticleRayleigh Damping in v4.2
Hi, I'm trying to analyze a cantilever beam and I need to change Rayleigh damping parameters (alpha and beta) but I am not able to find them in Comsol v4.2! I knew how to do it in 3.5! Please advise...
View ArticleTube Heat Exchanger
Dear COMSOL community. I am new in COMSOL and I have some problems with my simulation. Mayby anybody could help me. I try to simulate a heat exchanger. Steam is condensing on the outside. The heat is...
View ArticleHow to export data in excel format?
Hey Ivar, I want to export my figure into excel format. and replot it in matlab. Is it possible ? Thank you very much!! Baofeng
View Article'Turbulent Two Phase Flow, Level Set' Module
Hi, We are designing a two phase (Air and Gas) burner model using 'Turbulent Two Phase Flow, Level Set' module with Transient Initialization. We are not getting any error when we compute the model for...
View ArticleIvar, could you please say something about the solver error?
Hi, I would like to model friction stir welding process. I used general heat transfer module and incompressible navier stokes module together. I do not have any problem with the heat transfer module,...
View ArticleInternal error in geometry composition, Comsol 4.2a
Dear Fellows, I want to make blocks with round edges in 3D. I use standard procedure, I define workplanes, make geometrical objects in 2D, do "extrude", end on the end - INTERSECTION. When I do these...
View ArticleCombustion Flame
Does anyone out there have any experience with combustion modeling? I'm trying to model the combustion of methane and air. Any input would be appreciated.
View Articlereacf
I have not found the mathematical formula for the "reacf" operator. What is it? Another issue: When I integrate "Current density norm" = ec.normJ or reacf(V) over an insulating surface, I get a nonzero...
View ArticleNumber of degrees of freedom solved for: 96195
Dear Sirs, I am trying to understand from where the number 96195 comes from. In particular, the mesh I am considering is a tetraedral mesh of a rectangular domain in 3D ( width = 5 cm, depth = 1.5 cm,...
View Articlezero induced current density at conductor boundary, is this normal?
I'm modeling a coil-over-steel-plate system using 2D Perpendicular Induction Currents, Vector Potential mode (emqa), time harmonic analysis (f=1.0 MHz). The calculated induced current density Jz at the...
View ArticlePML and scattering boundary condition in v4.3
HI, Is it necessary to define the outer boundaries of a PML as scattering boundary layers to obtain the losses of a leaky waveguide? In v3.5, I have defined the outer boundaries as perfect electric...
View ArticleHow to have correct expression for stop condition
Dear all, I would like to set the stop condition so when the internal time step below 1e-9, it will stop. I set it as timestep-1e-8, so, so when it is below 1e-8, i will expect it to stop. However,...
View ArticleIntegration with upper bound depending on x
Dear All, I am trying to integrate a function of x in 1D between 0 and x for all x and create a new continuous function, varying with x. It seems the integration coupling (intop) does not have the...
View ArticleComplex eigen frequencies
Hi there I used to solve eigen frequency of a piezoelectric diaphragm with Comsol 3.5 and obtain real values for the eigen frequencies as real numbers. But now that I use version 4.3 for the same...
View ArticleLiveLink matlab, how to plot field distributions?
Hi, I am considering an optical fiber in 2D, where I calculate eigenmodes using the RF module and do a sweep of the wavelength in Matlab using a for loop. Inside the for loop I only have the parameters...
View ArticleBending stresses due to vibration
hi, this is rotor dynamics. A shaft supported by two ball bearings is under vibration due to misalignment of the shaft with the coupling. now i need to calculate the bending stresses in the shaft due...
View ArticleHysteresis Losses on synchron motor
Hi All, i desperately try to evaluating hysteresis loss in comsol way. there are a few commonly used formulas. i think, the easiest is to measure the area enclosed by the hysteresis loop in a cycle...
View ArticleProblem: Oil Droplets Seem To Dissolve In Water (Two-Phase Flow, Level Set)
I have a problem with my "Two-Phase Flow, Level Set" simulation in COMSOL 4.2. I am trying to simulate the formation of oil droplets in water by hydrodynamic flow focusing. The water and oil are...
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