Piston Cylinder Simulation
Hi, I am trying to simulate oil flow in a piston cylinder assembly. The flow is incompressible and so I am using the Incompressible Navierstokes ---> Transient analysis application made. However,...
View Articlediffusion convection issues
Hi, I want to simulate the concentration variation of nano-particle in a micro-fluid channel under magnetic field, and to show nano-particle will build up in the region near the magnet. I have built a...
View ArticleModel the flow of a visco-elastic material
Hello, I'm currently working on a model and i can't seem to tackle a few problems. If you would be so kind to help me out, I would be entirely grateful. The model is a 2D section of the real 3D...
View ArticleSegregated solver steps do not involve all components.
Dear Mr. Gene, Please I noticed you had a segregated solver problem a couple of years ago. Please did you solve it? If yes could you be kind to share you experience with me? I am actually facing it on...
View ArticleRegarding out-of-plane thickness in Conjugate Heat Transfer
Hi all, I assume that default out-of-plane thickness is 1m for Conjugate Heat Transfer or Non-Isothermal Flow. I would like to if there is a way to modify it to some other value like in Magnetic Fields...
View ArticleSolver settings for 3D k-e model
When faced with 100K DOF comsols defeault solver is a 1 or 2 level multigrid with GMRES as iterative and PARADISO as linear solver. Some papers on CFD and mass trasfer (such as the one by Birgit Stute,...
View ArticleInsufficient result in flow velocity profile.
Hello guys. I'm doing simulations with the attached geometry. Firstly, I should do a fluid flow calculation. The small center circle is the inlet, and the other (or 2 of 4) are the outlet. The diameter...
View Articlecfd simulation
Hello everybody! I would like to know what is the residual and tolerance factors, in the tab solver/fully coupled. How can we change them in order for the solution to converge? Thanks in advance.
View ArticleSelection of surfaces on interior geometry
Hello, I am working on a project involving the simulation of airflow through a room. When I import a sealed room, I am unable to select the desired inlet and outlet within the room. When I do not place...
View Articleauxiliary sweep
Hello everyone, I am simulating a reacting flow with a rather fast reaction. This problem does not converge, and I found out that I should try an auxiliary sweep with a parameter in front of the...
View ArticleFailed to evaluate variable jacobian!..
Hi everybody, I want to simulate a heat transfer and navier stokes problem. I have two subdomains. In one of the subdomains only the heat transfer equation is solved, not the navier stokes equation. To...
View ArticleMeshing
Hi, I need to mesh a microfluidic model with different mesh sizes in different domains to save on computing time on the unimportant regions. Consequently, I've partitioned the model into different...
View ArticleMass Fluxes Does not Match on Boundary, and Different Results from Different...
Hi all, I'm currently modeling a mass diffusion problem, using Transport of Dilute Species and Laminar Flow modules. On the boundaries of two adjacent diffusion domains, I use the Stiff-Spring method...
View ArticlePeriodic flow condition
Hi, I am confused about how to use the periodic flow condition. I have a long and repeated geometry, and I want to model just one section of it (since it is repeated anyway). Geometry is very simple...
View ArticleFluid U-flow in a cylindrical tube
I am trying to model a U type fluid flow through a cylindrical tube. But every time while computing, it shows this error, " Failed to find a solution. Maximum number of Newton iterations reached....
View ArticleParticle Tracing (the stored trajectories have the wrong dimension)
I have a model in comsol 4.3 with a 3D and a 2D geometry. The model calculate fluid velocities in the 2D geometry. I added the 'Particle Tracing for fluid flow' physics to the 2D geometry but after the...
View Article2D TRANSIENT Heat Transfer Problem
Hi everyone, I am encountering an error in the time dependent situation - Failed to find consistent initial values, last time steps not converged. I have specified 'initial values' and the required...
View ArticleError in DEP simulation-Help
Hi All, I m getting simulation error while simulating DEP based separation.I choose particle tracing with time dependent study, I m able to simulate for laminar-starionary, electric field-stationary.....
View ArticleBoundary as a thin wall (baffle) in non-isothermal model
Hi I'm a new member. Now I'm simulating about 3-D non-isothermal model in Comsol (4.3b). I try to make geometry box, 2 meter(H), 1 meter(W), and 5 meter(L). But in the box must have plate (like a...
View ArticleRarefied Gas Flow module
Dear all, Is it possible to link a physic with a study its not preset for? For example, I want to perform eigenfrequency analysis in the free molecular flow but I am unable to link these two even...
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