Difference between Initial Stress and Boundary Loads
Hello, I like to get some help in the basics. I have a 2D axisymmetric model of a thin membrane. The ends of the membrane are fixed at the outer edge using Fixed Constraint node. The membrane has a...
View Articlemutual coupling waveguides
Hi everyone, I am trying to model two oppositely located waveguides for heating fluids. I am using 4.2, Electromagnetic waves in RF module and non-isothermal module in heat transfer module. I am trying...
View ArticleEmpty parameter list
Hi everyone, I'm beginner to COMSOL and I'm modeling hyperthermia cancer treatment with magnetic nano particles. I'm using bioheat transfer for the body cells, mixture model for modeling nano particle...
View ArticleMaximum number of Newton iterations reached
I have imported a 3D meshed model from simpleware to COMSOL 4.3b. Some of the materials of the model are Hyperelastic, Neo-Hookean. While running the model via Direct Solver at 99% of progress there is...
View ArticleHow to change colour scale bar width?
Hello, I am using COMSOL 4.2a and when I export post processing image then the scale bar in the image is very thin and almost invisible at the same time the range of values is also not visible. So I...
View ArticleRF Module Incident field
I am quite new in Comsol. I have been doing some simulations in optics with Comsol. I was interested in observing the interaction of a small particle sitting on the interface of two layers, maybe air...
View ArticleTest function for the gradient
Dear all, I was reading the documentation and I couldn't find the answer for this question: Assume that you are using P1 elements to discretize your solution with respect to the space (2D). Your...
View ArticleS-parameter and port BC
Hi everyone I am studying the emissivity of a surface. In order to consider higher orders of reflection or transmission, we need to add several port BCs. for example in my case I am trying to obtain...
View ArticleAutomatic Remeshing for Moving Meshes
According to the release notes, version 4.2 is supposed to have a new automatic remeshing feature for moving meshes:"For a simulation that includes a moving mesh, a new automatic remeshing feature...
View ArticleDeposition rate using particle tracing module
Hi I have modeled a reactor using the "fluid flow" and "particle tracing module". A substrate wafer is placed across the flow channel. I have implemented the boundary condition so that whenever a...
View ArticleState Space Export
Hi , i have build a simple cantilever beam model using time depented model. after defining the points of forces and parameters, i want to export the model to matlb (State Space Matrices) so i could...
View ArticlePacked bed mean field model
Hi, I am trying to solve the time-dependent concentration profile in a packed bed using the mean field theory rather than the whole CFD definition of the problem. The mass giving rise to the...
View ArticleRadiation heating
Hello, we are trying to solve the following problem: We have four radiant heaters on top of a rectangular cavity and two at the bottom. So, we could set up a symmetric problem two at the top and one at...
View ArticleApplying a step function at an unknown time
I would really appreciate if anyone can help me with this issue: I need to apply a load on a boundary. my problem is that this load needs to be applied only if the deflection of a beem has exceeded a...
View ArticlePDE
I am currently working on COMSOL 4.0a. Can anybody tell me how the variables for stress are defined in COMSOL? Since I want to define a Coefficient PDE, which its diffusion coefficient (c) is coupled...
View ArticleBoundary error
Hello, I'm trying to calculate the electric field distortion produced by a water droplet, which I simulate as a half sphere. When depositing the droplet on flat surfaces, like the one shown on the...
View ArticleHow to write stop condition in solver
I am using a COMSOL V 3.5. I would like to use stop condition for time or temperature in solver parameters. Can you suggest me the how to write a equation for particular time or temperature? Thanks in...
View ArticleAcoustic transmission through periodic structures
In the underwater acoustic structure interaction problem I have done a @D problem in 3.5a version. When I convert this to 3D in 4.3b what is the periodic boundary condition to be given. In 3.5a version...
View ArticleAcoustic properties of a ventilation duct
I am trying to model a ventilation duct to try and and understand what happens to sound within a duct and when it exits the duct into a room. I am trying to look at the sound pressure variation and...
View Articleboundary condition dependent on dependent variable
Hello everybody, In a coupled heat and mass transfer problem, I would like a pressure BC to get updated at each time step. Let's call this pressure pv. pv depends on the temperature and pressure...
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