Mesh problem combining the physics of "fluid-structure interaction" and "heat...
Hello everybody, I'm working with a simulation model of a bimetallic strip inside a microchannel with laminar flow. I'm using both physics the fluid-structure interaction (with a dynamic mesh) and heat...
View ArticleFailed to find consistent initial values
Dear COMSOL users! I am trying to model wormhole formation during the acid injection in the reservoir. It is two scale model: Darcy scale and pore scale. I am using 3 physics: Darcy law, transport of...
View ArticleCarrier diffusion in photonic crystal
Hi, I would like to ask if anybody have tried to calculate carrier diffusion in photonic crystal using COMSOL?
View ArticleSolution does not converge when source term is added?
I am trying to solve laminar flow in porous media and vapor domain. The vapor domain is attached to porous media. I use laminar flow in vapor domain and flow in porous matrix in the another domain. The...
View ArticleMatrix has zero on diagonal
Hi experts, I mat a problem when simulate a AC/DC model. it came out as below: Failed to find a solution for the initial parameter. Segregated group1 Matrix has zero on diagonal. Returned solution is...
View ArticleThe inlet condition in the plasma module
Dear all, I am using the DC plasma module to model a certain discharge. I recently wanted to use the inlet condition in one of my simulations. But the problem is that I always get 'Inconsistent Initial...
View ArticleHow to find partial derivative of dependent variable at one point
I am using diffusion time dependent model with two dependent variables cp and cb. My equation of cb requires me to input "partial derivative of cp at x=0" i,e cb=k*pd(cp,x)|(at x=0) k is constant. And...
View ArticleConvergence problem-Dielectric Barrier discharge
Hello I am modelling an AC-DBD. I am facing convergence problem as i run my model. The error that shows up is Repeated test error failures Failed to find consistent initial values. Last time step is...
View Articlesimulating an imported mesh (from matlab)
Hi, I'm trying to simulate a prescribed displacement (one end is fixed and the other one displaced) of a mesh created in matlab (the geometry is from a microCT image). The problem is comsol dons't...
View ArticleHow do I extract the gradient at a specified location?
Hello, I'm new to COMSOL. I tried to use COMSOL to solve Fick's second law, Ct=Cxx, for a 1-D geometry using the coefficient form PDE. Once I have C, which is a function of x and t, I'd like to plot...
View ArticleCurrent-temperature dependence in semiconductor
Hello In my research work I've got simple heat transfer LEDs time domain model. First problem is simple and typical. I supply various forms of current impulses and watch time-temperature dependence...
View ArticleWhy do I get convergence error when I increase the mesh?
I solved a model with low mesh like 11. The results were not satisfactory at all but no error. Then I increased the mesh to 6000, and it stuck in 4% and after 20 minutes I got the convergence error....
View Articlehow to plot error vs iteration number comsol?
All I can see is the "reciprocal of step size" vs "Time step" in the progress window of the solution but I do not know how to plot error vs iteration number in comsol. Can I do it real time or it will...
View ArticleWhat is "Maximum Element growth rate" and "curvature factor" in the Mesh...
Under "Mesh" node and then under "size" , I see a section named "Element size parameters". Inside it there is this "Maximum Element growth rate" and "curvature factor" that Comsol always automotically...
View ArticleError : Failed to find consistent initial values
Hi, I have made a 3D EHL model using Thin-Film Flow, Shell and Solid Mechanics. When computing the model, the following error is popping:"Failed to find consistent initial values" Maybe this error is...
View ArticlePN optical modulator
Hello, I am a student in TUD and I have started to work with COMSOL. My task is to model and simulate PN silicon optical modulator. I am using Semiconductor module. I have couple of questions I would...
View ArticleStacking objects
For a project we have to analyse the forces of the stacking of ancient pots(amphora). We have tried everything we could think of with contact pairs and without but nothing seems to work. In the...
View ArticleSolving coupled PDE's in COMSOL 5.2
Hi! Is there any way to solve coupled PDE's without using the Coefficient form PDE? I am not able to fit in my equations using that module. Also, How can i custom add boundary conditions(I am not able...
View ArticleHow to define for comsol to use only one cpu for the solution? Also using the...
When I run Comsol Sometimes I need it to work only with one CPU. Is there any option anywhere to do that or Comsol automatically decides on that? Also for some solutions, I noticed my CPU is at 87% and...
View ArticleWhat are the physical and virtual memory in comsol interpreted during the...
When I press solving to compute my model, I always see the numbers at the bottom right "physical memory" and "Virtual memory." What is the importance of these numbers? How do you interpret them? I have...
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