Setting initial values for an iterative solver
Comsol user interface shows some options for setting initial values at the stationary study step at 'Initial values of variables solved for'. These are either zero or a solution - but we want to set...
View ArticleCFD - Surface roughness
Hey guys I really need your help on this one! I was wondering if any of you could tell me about the default settings of surface roughness's in COMSOL? All I've found about it in the documentation is...
View Articleprescribed dispacement
Hello, I'm trying to do a simple thing with structural mechanics module, but I don't get convergence. I attached the model. I'd like to apply a prescribed displacement at boundary 2 and check the...
View ArticleHow to solve laplacian euqations on dielectric sphere?
Hi everyone, I'm a starter of Comsol~ I was trying to solve laplacian euqations on a dielectric sphere with a non unity permittivity e, where a uniform electrical field E was applied outside the...
View ArticleHow to get the intensity (or amplitude) of transient laser pulse?
Hi, I have a question on getting the intensity (or amplitude) of laser pulse in RF module. After having created a laser pulse as the sample of 'Propagation of a 3D Guassian beam laser pulse', how can...
View ArticleAC sources
Hi All, I am working on a project using comsol and I need to define an AC source. I want to use the Ac source to see the effect of bioheating. I don't know how to define an AC source and how to use...
View ArticleFGM materials
Hi I'am working on the vibration of FGM plate, and I need to change the gradient parameter in for several values ,so I tray to define a material Matrix ;case of anisotropic materials , after...
View Articlevariation of effective index with lambda
Hi everyone ! I want to plot the variation of effective index with lambda in COMSOL 4.3.151.First i think I have to define freq=c_const/lambda in parametric section.But after that what I have to put in...
View ArticleLaminar mixture model
Hi all, I am trying to simualte a steady state flow of liquid having nano particles of Copper (d=25nm). I have to use Reynolds number for which the Stokes flow is valid. Constant void fraction of 0.022...
View ArticleNatural Free Convection
Hello, I'm attempting to model the temperature rise above ambient over the period of one day within a sealed concrete trough buried in soil with its top exposed to outside air. I have successfully...
View Articlethermal magnetic motor and or generator
Along time ago I had the thought after reading and studying about patents by Edison and Tesla on the development of a thermal magnetic generator and/or motor Has anyone ever tried to follow through...
View ArticleHow to applicate a Magnetic field
Hello I'm beginner wuth Comsol and i wish to applicate a magnetic field into the metal structure of a surface acoustic wave sensor. Thank you for your help
View ArticleLithium ion battery 1D model: solver error
hi, I am trying to solve the Lithium ion battery model from the model library (li_battery_1d). I am always getting this error message while solving study1 in it .Please help me on this. Repeated error...
View ArticleNo eigenpair solution selected
Hi I'm new in COMSOL. I want to find out eigenfrequencies of a pinned-pinned rectangular concrete beam. this beam has 5X5 cm cross section. It is a simple problem but I have some problems in getting...
View ArticleError to initialize a physics interface created with Physics Builder in...
Hi all, I am trying to compile with LiveLink for Matlab (Matlab version MATLAB_R2012a) a Comsol model (Comsol version COMSOL 4.3.0.151) that uses a physics interface which I created with the Physics...
View ArticleMovement of air due to thermal expansion
Hi everybody! I'm trying to simulate the movement of the air in 2D and I only get errors. I use two physics: laminar flow with heat transfer. I've created a square full of air and I put easy boundary...
View ArticleUnsteady Analysis
Hi, I am solving unsteady state navier stokes equation with a volume force term. My volume force term contains a term like sin(t), now i want to make sure that the unit of angle in comsol is radians,...
View ArticleUnsteady Analysis
Hi, I am solving unsteady state navier stokes equation with a volume force term. My volume force term contains a term like sin(t), now i want to make sure that the unit of angle in comsol is radians,...
View Articleerror in model library
Hi, guys. I am learm a model in model library , the name is "domain_activation_llmatlab.mph". I am doing the example step by step, but at last I find that i can't run the matlab code. There is a error...
View Articleerror in model library
Hi, guys. I am learm a model in model library , the name is "domain_activation_llmatlab.mph". I am doing the example step by step, but at last I find that i can't run the matlab code. There is a error...
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