Velocity gradient expression in 2D-axisymmetric
Hello, the velocity gradient tensor for a 2D-axisymmetric problem presents, for the phiphi component, the following expression chns.graduDGphiphi = if(abs(r)<0.0010*h,d(u,r),u/r) does anyone know...
View ArticlePoission's ratio problem related to Structural Mechnics
Dear all, I just started to learn COMSOL and tried to conduct a simple simulation of deformation of an elastic plate by a face load. I used Solid Mechanics model in 4.3 edtion. 1. When I set the...
View ArticleElectric field not adjusting with moving mesh
Hi, I have created a model which is effectively a capacitor with a moving plate. I have ground electrodes on the fixed top plate and +/-100V electrodes on the bottom moving plate. I am using ALE with...
View Articlehow to set the domain temperature?
In heat transfer in solid model I need to set the domain temperature as a constant value(such as T=300K) In all the computing process. Now I can only set the boundary temperature.Thanks.
View Articlehow to set the domain temperature?
In heat transfer in solid model I need to set the domain temperature as a constant value(such as T=300K) In all the computing process. Now I can only set the boundary temperature.Thanks.
View ArticleAC Electrical Field simulation in interdigit structure
hi I want to do AC filed simulation for interdigit structure. I am wondering what kind of physics should I select and how I can apply AC signal to my structure? I would appreciate any help
View ArticleDefine simple-support boundary condition of a beam (Solid Mechanics)
Hello everyone, I am a new Comsol user and through the past few months I have made simple models comparing the results with some theoretical models. I will bother you with plenty of questions the next...
View ArticleIssues with Full Coupling of Physics
Good day, I am having issues with fully coupling two physics. My system contains the solid mechanics physics coupled with a general form PDE to model concentration change and the diffusive properties...
View Articlejpeg to dxf
Hello everyone, I am trying to import an image in to my model however i am not clear on how to convert the .jpeg to .dxf, i tried a few online softwares but of no use. May your expertise assist me....
View ArticleAdding a weak contribution to a fluid domain
Hello, Can anyone please help me to add a modified continuity equation in fluid domain, I came to understand that by adding a weak contribution node, it is possible to modify equations.....Has someone...
View Articlewhich kind of solver?
Hi all, i am doing some kind of simulation in RF using 4.3 version comsol and the RAM of my computer is about 30G , how to select the best solver to use almost of my RAM to finish the task as faster as...
View Articleanalytic function in another analytic function
Hi, I have two questions: 1. an analytic cunction that has one argument - sigmaxx that I want to incorperate in another analytic function that has another argument = ec.normE. I cant do it no matter...
View Articlecontinuous magnetic separation model
I am modeling a continuous magnetic separator. As it can be seen from the model attached, I have five magnetizable wires that get magnetized by the magnetic field boundary conditions applied to the...
View ArticleAsynchronous Machine time dependent startup, singularity error
Hello, I am trying to simulate a ASM in the rotating machines physics, time dependent. The Stator slots are coupled to the electrical circuit physics for a Voltage excitation The rotor slots are also...
View ArticleScttering problem using comsol4.2
I wanted to calculate scattering absorption cross section and thereby extinction for a nanoparticle. I am not sure how to go for that in comsol4.2. Can anyone please tell a basic flow to accomplish...
View ArticleRF: Emitting planar light from PORT (3D)
Hello my friends. I am trying to construct a model where the port is placed along the y,z-axis and emits light in the x-direction. However, I do not want to just emit light normal to port's surface, ie...
View ArticleFlow in a pipe with a very large aspect ratio
I'm trying to solve what should be a very simple problem as part of a larger project I'm working on. It's just laminar flow in a pipe of length 14,000 feet and radius 0.04 feet. I'm just trying to find...
View ArticleSymmetry
Dear all, sorry the continuous questions today! I am going to use symmetry for the geometry as in the picture I attached. The simplified geometry is a multilayer (only the green part) composed of...
View ArticleUnknown heat source in heat transfer-laminar flow coupled model
Hi all, I am modeling a volcanic conduit (5 m wide) moving up through a "host rock." I want to analyze the thermal budget of this situation. The conduit is a rectangle (Heat Transfer in Fluids, Laminar...
View ArticleHow to use alpha ( thermal expansion coefficient) as piecewise function.
Hello evrybody, I m using a time dependent problem of a beam restricted at both ends. When we use alpha ( thermal expansion coefficient) as a piecewise function, then they give error as "Failed to...
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