Can I link models or studies via an internal variable?
Hi, I'm struggling with a diffusion-only problem using dilute species transport. I would like to set the flux of species B into my system by setting it as the equal to the negative of the final...
View ArticleAcoustic-Structure Model
Good evening, I am attempting to model the response of a fixed beam when driven by an acoustic source within a fluid. Initially, I used an eigenfrequency study and obtained results that make sense to...
View ArticleTrouble coupling heat transfer physics for both fluids and solids
Hey all, So I'm getting stuck with my model where I try to couple three different physics. The three physics are: Electric Currents, Heat transfer in Solids, and Heat transfer in Fluids. Basically what...
View ArticleLater version of COMSOL has robuster and stabler solvers
Dear all, I just want to share my recent experience with a convergence problem. During last several weeks I was struggling with convergence problem. The model has two 2nd-order PDE and Electromagnetic...
View Articlesegregated vs fully coupled solver in comsol
Hi All, I have compared these two solvers for a heat transfer case with surface-to-surface radiation. Acutually simulation results, i.e., temperature distribution in the domain, are quite different....
View Articleout of memory during assembly
Hi All, I am running a heat transfer with radiation, and the error message says "out of memory during assembly". Rigth now, I am using a workstation with 48GB memory. I check the element number, and it...
View ArticleSkip unsolvable parameters in parametric sweep?
General question. I run a parametric sweep and occasionally one of the parameters causes a simulation that doesn't converge. e.g. the parameters are param = 1, 2, 3, 4, 5 meters and this simulation...
View ArticleStructural optimisation
Hi, I am using a livelink from Solidworks to Comsol in order to import 3D geometry and quickly define some geometry parameters. I've made a structural analysis with applying torque load to my model and...
View ArticleMultiphase Stirred Tank
Hello! I'm trying to simulate a stirred tank of water with air bubbles in 2D Axisymmetric model. But, In the bubbly flow module doesn't exist the condition "sliding wall" Can you help me with this?...
View ArticleCoupling Stationary fluid flow and transient solute transport to AC/DC module
Hello, I'm not the most proficient COMSOL user yet, and I have a 2D problem in v3.5a that would seem to be rather simple but has proven difficult to me thus far. My problem is as follows: I want to...
View Articleinternal DOF
Hi All, I am running a case with element number of 0.18M, and number of degrees of freedom solved is 311413 (plus 200428 internal DOFs). What is the internal DOF? And I select the fully coupled solver....
View Articleradiation heat transfer
Hi Ivar, Since you are the expert in radiation heat transfer, I wonder if you can help with some problem in radiation heat transfer. I am running a 3D case with surface-to-surface radiation heat...
View Articlefrequency domain using reduced basis (modal)
Hi all, I'm trying to make a frequency sweep on a (big) model of an acoustic cavity, with specified surface impedance as boundary conditions. If I use the "Frequency domain" study, everything goes...
View ArticleCUDA and COMSOL
Dear all, I have a new NVIDIA Quadro GPU and I would like to use it to accelerate my simulations, is it possible to use it somehow? I looked for some informations and it seems to me that CUDA it's...
View ArticleCoefficient form PDE with Dirichlet boundary conditions - Problem with...
Hello, I have a Coefficient form PDE with Dirichlet boundary conditions with two dependent variables. The dependent variables range -5<v1<5 for v1 and 250<v2<600 for v2. The model converges...
View Articlehow to simulate the strain/stress of the beam at 1m/s2 70Hz acceleroration?
Dear Sir, I have read several of your very useful answers here. Thanks a lot. I built a beam structure using the solid mechanics model, did the stationary strain/stress analysis without any problem. I...
View ArticleRadio frequency (and general) convergence question
I have a model which COMSOL is having a very difficult time finding a stationary solution for - the solver gets a fair way, but then tends to oscillate and never settles down to a converged solution....
View ArticleMulti-steps simulation (100 and more)
Hi! Is there any way to optimize solver to solve hundreds of steps? I'm trying to simulate tunnel construction process and there is a lot of steps. Right now with standard settings at the beginning...
View ArticleCan I link models or studies via an internal variable?
Hi, I'm struggling with a diffusion-only problem using dilute species transport. I would like to set the flux of species B into my system by setting it as the equal to the negative of the final...
View ArticleAcoustic-Structure Model
Good evening, I am attempting to model the response of a fixed beam when driven by an acoustic source within a fluid. Initially, I used an eigenfrequency study and obtained results that make sense to...
View Article