Defining a Piecewise function of two variables
Hello, I am trying to model NMR diffusion in COMSOL 4.3 and need to define a function beta at three different time intervals as follows: beta = gyro*(g*x) (0 < t < 0.016s) beta = 0 (0.016s < t...
View ArticleHow to generate a "Join Data" set from parametric steps?
How to generate a "Join Data" set from two stationary and parametric steps? Hello everybody. Does anyone know how to merge two solutions when one of them is the continuation of the other? For instance,...
View ArticleSimulation of the magnetic fied
Hi, I have one physical NdFeB magnet and I need to simulate this magnet in Comsol 4.2a, but I dont know exactly how to do it. I know these parameters of the magnet: Remanence Br = 1380 mT Coercivity...
View ArticleMaxwell stress tensor integration
Hi everyone! I'm still trying to compare the electrostatic force calculated by the expression (F=0.5*epsilon*V^2*A/g^2) with the result coming by Maxwell stress tensor in COMSOL. I used the suggestion...
View ArticlePlease help! (error: Undefined value found)
Hello everyone, I’m working on the following model from Comsol library: Batteries and fuel cells>>ht_pem. When I change the geometry to a more complex one, for example using two or three...
View ArticleEigen-frequency analysis of metal grating
Dear all, For a metal grating (see attached Structure_Reference.jpg), now I would like to analysis the dispersion relationship of surface plasmon wave supported by a metal grating, which propagates...
View ArticleHow to know a material's parameter value
Hi people, i have a newbie question: in my heat transfer simulation i'm using a wood block (kingwood of Comsol material database). If i look the parameters, the value of density rho is not indicated:...
View ArticleHeat Transfer in Soils
Hi, I am a comsol user and I want to have a 2d axisymmetric model. In my model, I have a soil sample that I put a steel bar in the soil. I want to heat the steel bar with a constant temperature 500(k)...
View ArticleConvergence of Solver with Hyperelasticity - Problems
Hello, I've modeled a cantilever beam composed of Magneto-Rheological Elastomers (MAE) that bends when subjected to a magnetic field. The MAE used in the model currently uses a linear elastic material...
View ArticlePlease help me find how to achieve this function.
It seems to be a simple problem but I can't figure out how to make it. Description: a 2d transient model of a square is built, the left, bottom, and right side is thermal insulation and the top side is...
View ArticleSimulation of a floor heating
Hi all, I want to simulate a floor heating in a 2D modell. Floor heating systems release about 90 % of heat in the form of radiation and about 10 % in the form of convection. So is it possible to take...
View ArticleHow to change equation during a transient solution in V4.3
Hello everybody, I am simulating a transient solution by using transport of dilute species. I would like to change the equation during a transient solution and use the initial value of simulation 2...
View ArticleChange coordinate axis label
Hi Guys, Does anyone know how to change the coordinate axes labels in COMSOL 4.3? As we know, if we have a 3-D model and click 'Default 3-D view', we can observe that X axis is in the upper right...
View ArticleThermal Conductivity as a function of temperature
Hi all, I am trying to include thermal conductivity as a function of temperature in my model but its giving me error 'inconsistent unit'..let us say the function is -1.27E-9*(T)^3+8.09E-6*(T)^2-...
View ArticleRotating machynerry with rotor flow
Hello I would need to deal with this problem. I need a rotary device that had a rotor with one piece in the shape of a hollow ring which rotates to fill the metallic dust magnetic materials. But there...
View Articlecannot select an edge to become an outlet boundary
Hi! After struggling for quite a while with 4.2a, I haven't been able to enable one edge to become an outlet. What I did was to construct two objects: the first one is a sequence of lines, which I then...
View ArticleDefining wires in 3d models
I am trying to simulate a process that includes flow, electrostatics and mass conservation. The model is simply a rectangular. One edge is grounded and the opposite includes 59 wires. The grounded edge...
View Articlevolume within a closed isosurface
Hello WIthin a 3D domain containing closed isosurfaces, is there a way to calculate the volume of material contained within each isosurface? Many thanks Dan
View ArticleComsol 4.0
Yesterday I got a copy of the trial version of Comsol 4.0 at an on-campus workshop, with all the modules. My very first impression after spending all of maybe three hours with it: It's going to take...
View Article