sinusoidal voltage to time dependent solver
I am trying to apply sinusoidal voltage to a model with time dependent solver. I apply the voltage based on a function but it doesn't show anything. the model is attached. thanks
View ArticleThin film joule heating
Dear all, I'm interested in whether I could apply an thin film joule heating approximation to model an MEMS heater. (Dimensions are 200nm x 0.025mm x 2.5mm on a 1um substrate.) I've got the thin film...
View Articlegrid control
Hi, I am trying to plot a graph using the 1D plot Group and Line Graph, but I want my graphs to appear with the background grid invisible but I can't find an option to remove the grid from the graph....
View ArticleMetal film with subwavelength size hole: Transmmittance and reflectance study
Hi I'm novice in comsol RF simulation. I'm trying to simulate transmittace and reflectance throught metal film with subwavelength size hole. My structure will consists of Air/metal/semiconductor...
View ArticleTest function for Electric field
Hey all I am working in the 2D piezoelectric module and I want to take weak forms of Electric field in different direction, test(pzd.EX) and test(pzd.EY) but its showing error. When I try by making the...
View ArticleHow I can add data for a solution to a new study?
I'm working on the simulation of an iron foundry, I made a transient thermal study, and I exported data solution in time 200seg temperatures. I would like to know how I can add the output exported to a...
View ArticleError: 7248: Undefined value found.
I tried to solve a 3-D model with a fine mesh. half way through the program stopped and I got this message: Error: 7248 Undefined value found. When I click Details, there are two lines in red that say:...
View ArticleSurface roughness
Hi, I'm new to COMSOL Multyphisics. I successfully built a 3D model of Laminar pipe flow. My idea is to build a pipe that is made of stainless steel and then change to glass with the same diameter. I...
View ArticleError: Failed to evaluate variable
Hi! Can somebody help me with troubleshooting this error:"Cannot evaluate expression. Failed to evaluate variable. - Variable: mod1.es.Ex - Geometry: 1 - Domain: 1 Failed to evaluate expression. -...
View ArticleMagnetic Particles Path Tracing
I want to plot trajectory of magnetic particles in a magnetic field of coils designed by me. When I use the built in particle path tracing module , it does not give any option to define to define...
View ArticleMagnetic Particles Path Tracing
I want to plot trajectory of magnetic particles in a magnetic field of coils designed by me. When I use the built in particle path tracing module , it does not give any option to define to define...
View ArticleForced external convective cooling
I have what must be a stupid question about cooling by external forced convection. I'm trying to model a metallic object that is locally heated on one surface and that will be cooled on the other...
View ArticleUsing external file data for heat source
Hi all, I am trying to solve a model for heat transfer in solids using external data as heat source input. The geometric model is simple and composed of 3 separated bodies attached together by a...
View Articlerectangle equation
Hello, I am aiming to create a rectangle equation that depends on x and y in COMSOL 4.3a. I read an article in which the author created a similar one shown below: min(min(x,8-x),min(y,6-y)) in FEMLAB...
View Articlebiphasic flow
I want to do a simulation of a two-phase flow of a water drop in air with "comsol 4.2", but I could not, he displays this error "Failed to find consistent initial values. Last time step is not...
View ArticleNersnt-Planck model
can anybody give tutorial other then given in library, where Nersnt-Planck model has been solved by 2 or more species. I have solve the library tutorial but still I am not comfortable.
View Articlehow to create polar plot in journal bearing
hello, need some help from u all to plot these polar plot. these study about pressure distribution around bearing surface of hydrodynamic journal bearing.. radius bearing : 50mm height bearing : 50mm...
View ArticlePlane wave in RF module
I have been trying for a while to produce a plane wave using a custom transient waveform using the RF module with no success. I have gone back to try to reproduce the 3-D gaussian beam example file to...
View ArticleTwo very basic questions about direct solvers
Hi all, I have two very basic questions about direct solvers. 1. Why is there convergence problem with direct solvers? I suppose direct solvers inverse the matrix somehow directly, rather than...
View ArticlePDE Initial value
Hello, I am trying to construct a circle as my initial value on a 6x8 rectangle as my domain in the PDE general form of V4.3a. In V3.5a I can do this by entering sqrt((x-3)^2+(y-3)^2)-radius, but I can...
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