COMSOL Error for Initial Values(RF Module)
I am defining a model with different concentrations of oil and water and trying to measure the heat distribution by using the microwaves. But I obtained the error mentioning Initial values: THE...
View ArticleHigh Viscosity in Two Phase Flow
Hi, I have constructed a two-phase flow model, using the "Droplet Breakup in a T-Junction" model in the gallery. I managed to compute the default model successfully. However, when I change the...
View ArticleHow to define Function in Definitions / Variables.
I'm currently working on electrical simulation using AC/DC module. I define nonlinear electric conductivity for zinc oxide material using following function(ZnO) in subdomain settings, but it shown...
View ArticleHow to Improve Convergence in Natural Convection
I am wondering how I can improve convergence in my natural convection model. It is a simple model; an isothermal aluminum plate in water. The model starts out fine but as the run continues (transient...
View ArticleHeat Transfer
Actually, I need to give boundary condition to one of the part of my system. At that part, I will use cryocooler of capacity 1 W at 4.2 K, how can I give this boundary condition to particular part. My...
View Articleintegral
hi do you know if it possible to calculate this integral in comsol (attach file) ? thanks
View ArticleSurge impedance of transmission tower
Hi everyone. I am trying to model an overhead line system, in which the transmission tower should be defined as a surge impedance. I expect the wave will go down the transmission tower and get...
View ArticleStationary / time dependent solution differs
Hello everyone, my model is a U-shaped pipe in a concrete block. Cold water (1°C) flows through the pipe and the warmer concrete (11°C) surrounding it warms up the water inside the pipe. I used the...
View ArticleCooling Towers
Can we input humidity for simulating cooling tower on COMSOL 4.3a? Can you help me with amy examples, if any??
View ArticleDisplacement computation
hi, i hv designed a nanotube based pressure sensor, am getting some displacement values for pressure applied on nanotube boundaries but how can i know whether the result i am getting is right or...
View Articlethermal model
Hi everyone, I am working on a thermal model and used conjugate heat transfer for simulation. My problem is when i want to calculate the thermal efficiency of the flowing fluid (cooling) by identifying...
View ArticleSetting up a previously solved physics as an initial condition for a second...
I am new to COMSOL 4.3a and I have what seems to be a simple dilemma, but I can't figure it out. I have a model incorporating three different physics. I want to run COMSOL to solve for the first...
View ArticleFixing an Object to a Set Position, Mises Force, Fluid Dynamics
Hello, I am trying to design a 2D microfluidic channel using COMSOL Multiphysics 3.2b. Inside of the channel, I want to fix an object and use COMSOL to calculate the magnitude of the von Mises stress...
View Article2D TRANSIENT Heat Transfer Problem
Hi everyone, I am encountering an error in the time dependent situation - Failed to find consistent initial values, last time steps not converged. I have specified 'initial values' and the required...
View ArticleHow to plot the relative error?
I've just spent more than a whole day troubleshooting my model. However, if I could plot the relative error over the geometry, I believe it would have been solved in minutes. There was a problem...
View ArticleMultiphase Flow LS - Air Bubble in Water Cylinder - Conservative forms fails
Hello everybody and thank you in advance for any kind of help you may give, I am trying to simulate a simple kind of scenario, an air bubble in a water cylinder rising due to buoyancy force. I made my...
View ArticleProblem: "Variables not coupled to any dof" in multiphysic sequence
Hello to all. I have a problem with a multiphysic sequence on Comsol 4.0. In order to simulate the electromagnetic behavior of a rectangular waveguide with a dielectric block inside, that can be warmed...
View ArticleConcentration problem within micromixers: absurd concentrations, no mass...
Hello everybody. I am modelling micromixers and want to check their efficiencies. For that purpose, I first used the Incompressible Navier-Stokes model, to calculate the flow inside my device. I set it...
View ArticleSetting up solver loop for 2 physics.
Hi, I have a problem that involves EM wave (frequency around 10^14 Hz) and mechanical movement (frequency 10^6 - 10^8 Hz). Basically the EM wave will give a force on the structure, and the force...
View ArticleSome problems of Bandgap Analysis of Photonic Crystal (ver 3.5)
Hello All, I am trying to run the built-in model of Bandgap Analysis in ver 3.5. But I got some problem: Error: 6170 Failed to evaluate variable. - Variable: lambda - Global scope Failed to evaluate...
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