Using simulated potential to simulate magnetic field.
I have a simple 5 domain model, composed of roughly concentric spheres. I am modeling a transmembrane potential on the 3rd domain using the General Form PDE physics. This part is working correctly. I...
View ArticleGeometric Nonlinearity problem
I have an odd problem. I am trying to recreate the Large Deformation Beam model (www.comsol.com/showroom/documentation/model/204/) before I start my own project to investigate buckling. I was following...
View ArticleInconsistent uni-directional constraint with Conjugate Heat transfer
I am trying to model a simple high temperature hydrogen heat exchanger with the conjugate heat transfer module. While I have been sucessfull in modeling individual tubes of the hydrogen alone, I cannot...
View ArticleUMFPACK
I am using COMSOL 4, I want to solve a nonlinear equation. I can not find UMFPACK in solver list!!! Could you tell me where it is?! Thanks.
View ArticleCalculation of effective material loss (alpha-eff)
I was wondering while doing my undergraduate research that- if there is any way to calculate the effective material absorption loss (alpha-eff) using comsol. I know the equation, but i do not know how...
View ArticleLimit number of eigenfrequency solved for
Hi, In my optimization process, I would like to maximize one cavity mode's quality factor. But since there is a neighbor mode has higher quality factor. Comsol always optimizes the neighbor mode...
View Articlehow to solve these equations using comsol?
Hello Mr. Ivar, I am a new comsol user and have read many froum posts of you, so learned and kind of you. Recently I have meet a equation set and don't know how to solve it. The equation are as follow:...
View Articlehow to solve piecewise equations with integration using comsol?
Hello everyone, I am a new comsol user, recently I have meet a problem and don't know how to solve it. The equation are as follow: X=0, when V<0.5; d(X,t)=V,when V>=0.5; V=sin(2*pi*t); I don't...
View ArticleSegregated Group Solver different results
Hi folks, I have been using COMSOL for a while now and, sometimes, when facing a difficult convergence problem I do mess around with the solvers a bit. I have seen some posts here on the forum...
View ArticleUsing lower limit node
Hi, I'm trying to use the lower limit node, but I can't select any variables because the variables window is not there. I can select variables in the segregated step nodes. See attached file for...
View ArticleUnidirectional coupling of a time dependent study to a stationary study
Hello, I am using structural mechanics module and a stationary study to calculate stresses and strains in a simple 2D axi-symmetrical model. The model has a thermal expansion node. I have another study...
View ArticleOptimisation of processing parameters in laser sintering of metal/alloy powders
Hi everyone, I am new to COMSOL Multiphysics.. Can anyone help me in simulating selective laser melting(SLM)/direct metal laser sintering(DMLS) of metal/alloy powder media in layer-by-layer fashion? IN...
View ArticleFSI - High convergence problem
Hi all, I'm new to COMSOL and I have a problem that involves an interaction between air and a solid body. I am interested in the torque generated on the body by the moving fluid. My intent is to use...
View ArticleConvergence problems
Hi there, Could any one give a hand? I have no idea what is happening with the solver or the model. I am trying to model a laminar flow without any other physics. The default plots during solving...
View ArticleStudy
I would like to deform a component and strain it in the deformed state with internal pressure. How do I set up the study, so that these two processes run sequentially. The pressure load is to take...
View Articlethe mass matrix is zero
Hello I am trying to simulate my design. In the first step, I tried Mode Analysis but unfortunately I faced this error: The mass matrix is zero Please let me know how can I fix it? Of course I read...
View ArticleLaplace-Beltrami Operator on a Curved Surface
Hi all, When I use the Coefficient Form Boundary PDE (cb) on a curved surface, is differential nabla operator the generalized operator which implies the curvature, say, is the Laplace operator the...
View ArticleCombining pysics
Hey. I want to ask if there are any settings in COMSOL-e, when combining both effects of multiple physics into one calculation. For example, electric currents and laser heating in one componente behave...
View ArticleMy biggest wish for X-mas: Solution for crack modeling
Dear Comsol gurus, dear support, my biggest wish for X-mas was, that the new 4.4 release would finally provide some reasonable approach for crack modeling as being standard in other software packages....
View ArticleUsing simulated potential to simulate magnetic field.
I have a simple 5 domain model, composed of roughly concentric spheres. I am modeling a transmembrane potential on the 3rd domain using the General Form PDE physics. This part is working correctly. I...
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