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 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 ArticleHow to solve a derived PDE equation with coefficient form?
Dear all: I had derived a PDE equation in attachment. But the result seems to be not correct. Please give me a help. Thanks a lot.
View ArticleHow to assign automated input values?
Can we assign input values to faces of an object via .csv file or through any web based tools?
View ArticleParticle Tracing time plot
Hello, I am attempting to create a 2D map of drift times from release until contact with some defined surface. Is this possible to do in COMSOL? If so, how?
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 ArticleError linking Heat Transfer in Fluids and Turbulent Flow (Spalart-Allmaras)
I am using COMSOL Class Kit 4.1 to model a pretty simple flow of hot air in a vertical pipe. I was able to get the model to working using Laminar flow (all are steady state studies) and the Heat...
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