Free Convection - General Modeling
Hi, I'm new to Comsol and i'm trying to model free convection in a prety large domain. I've realised the model in 2D and it has about 1 square meter and in 3D it has about 0.5 cubic meters. I'm using...
View ArticleCoupling Solid Mechanics and Optics
Hello, I am trying to analyse some optical data that changes when strained. I want to deteremine the values for specific strain which means that I need to do a parametric sweep of strain. However, I...
View Articleeigenvalue shift with additional point, no mass assigned
Hi, I've met some trouble when calculating the eigen-frequencies of notched plate. I've compared three cases, the first one is a simply notched plate, the second one is a notched plate with one more...
View ArticleLaminar flow without outlet (mixing with sliding wall) does not find solution
Hey, I have been trying to simulate a system where a sliding wall is causing convection in a closed box. In brief, the system is a box with one wall sliding at a rate of 0.01 m/s. The other walls are...
View ArticleTime dependent Navier Stokes does not converge - inlet boundary condition
Hi all I am modelling a laminar flow problem in a micro channel in a transient mode. My model works well but when I change the inlet boundary condition to velocity instead of pressure it does not...
View ArticleAsymmetrical & one-directional torque on rotating particle about center point
My colleague and I have been struggling with COMSOL modeling recently. Specifically, COMSOL seems to calculate forces that should be symmetrical to be assymetrical about a zero point. In my case, I am...
View ArticlePlease help - Maxwell Boundary element integral
Dear all, I'm trying to solve Maxwell electrostatic surface integral equation, lambda*U(r) = 1/(2*pi)* Integrate( U(r') (r-r')/(abs(r-r'))^3 ds) for a sphere. Lambda is an eigenvalue and the...
View ArticleParameter list gives empty sweep
Hello, I am modeling a system intended to display light scattering off of a particle suspended in a liquid medium. I used Electromagnetic Waves, Frequency Domain (emw) and keep getting the error "The...
View ArticleWhat is the difference between solving in one step and solving separately
Hi, I have built a modeling including two modules, one is laminar flow and the other is transport of diluted species. Strangely, I found there is a little difference for the results between solving...
View ArticleStationary solver will not converge
Hi, I have a cylinder, and I'm applying a Gaussian load to one of its faces and trying to find the displacement field. I am trying to hold the center of mass stationary by applying a body force in the...
View ArticleLeasts-squares gradient-free optimization
Hello all, I've been trying to fit parameters of my model to experimental data (9 parameters), I can set up a least squares problem and solve it with the SNOPT algorithm. The only thing is that some...
View ArticleComputing two physics models Simultaneously
Hello, I am trying to combine MAGNETIC FIELD physics with Electromagnetic Waves, Frequency Domain physics for a Helmholtz coil application. In middle of coils is a FR4 board with transmission line on...
View ArticleMultigrid failure during solver
Hey all, I'm working on a 3D model of a microfluidic system using the laminar flow (spf) and transport of diluted species (chds) physics models. I've got everything modeled with all the physics...
View ArticlePML error
Hi all, Can someone point me what I do wrong? I tried to repeat Scattering from plasmonic nanosphere model, so I have Au sphere + Air domain (sphere) +PML/ABC domain (sphere). When I defining PML as...
View ArticleScattering Model Doesn't Compute
Hello, I'm trying to model the scattering effects of light off of a thin box. I used the model example "Optical Scattering Off a Gold Nanosphere" as a reference model. " I've tried a few approaches...
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 ArticleThermal expansion in a core wire
Hello, We are trying to simulate the thermal expansion of a guide wire from the medical industry, when it is exposed to 4 different temperatures in 4 different ovens. We are using the solid mechanics...
View ArticleHow to simulate 2 objects in free rotation ?
Hello, I try to simulate 2 objects A and B in free rotation, but I don't find the solution, Comsol say problem with solid.mises but I don't know how to resolve the problem, could you help me...
View Article3d laminar flow - solver problem: Segregated group 1.
Hi I´m simulating the convection heat transfer in a pipe. The external surface of the pipe receive solar radiation to heat the fluid that is flowing. I start my model with the laminar flow and after I...
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