How to assign a 2D random function as porous matrix property (porosity)
Good morning, I really need your help, because I can't find anything in the help files. I have a model using the the Brinkman Equations module for 2 dimensional porous media flow. I want the porosity...
View ArticleConvective heat transfer coefficient
Hi everyone, I'm a beginner in Comsol and I have a very simple problem I can't find a solution for. Basically my model is in 2D and is very easy: I have an horizontal plate from which is flowing a heat...
View ArticleNusselt Number Calculation
I am trying to calculate the average Nusselt # over a flat plate vs. Reynolds #. Thus I need to take the average of the derivative of temperature in the y direction at the plate for the various...
View Articlecalculation of surface curvature, surface tension
Hello every body, I've a 2-D model in Comsol 4.2a where I use PDE and a moving mesh interface. I need to calculate the surface curvature on a boundary. I don't know how to do this accurately in Comsol....
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 Articlebaffled mixer example
I built and solved the baffled mixer example which worked flawlessly. I am making a mistake when adapting this to the frequently performed test tube research. I followed the instructions below from the...
View ArticleHelp with simulating condensation from a partially filled closed glass vial...
Hi! I am having trouble with a condensation simulation. A closed glass vial at ambient temp is partially filled with 10 degC water. When it is put in a cold room with temp of 5degC, condensation...
View ArticleLaminar outflow boundary condition does not converge!
Hello everyone, I am new to this programm and want to simulate the first part of a streamed circular duct. It serves as an hydrodynamical entry length to develop the velocity flow profile. In the...
View ArticleDynamic Pressure Inlet (turbulent flow)
Hi all, I have a question regarding a dynamic pressure inlet. I have a large 3D model with several pressure inlets and one pressure outlet. Some Informations: - Comsol 4.0a - Incompressible turbulent...
View ArticleRestart simulation with particles already in the domain
Hello there, I have another question regarding the particle tracing module. I have a model consisting of a Laminar Flow (chns) and a Particle Tracing for Fluid Flow (fpt) interfaces. Assume that I...
View Articletimestep in stationary study?
I am modeling laminar flow at steady-state. Error message: Undefined variable. - Variable: timestep - Geometry: geom1 - Domain: 2 Failed to evaluate expression. - Expression:...
View Articlecell Reynold number
Dear all, I have some confusion regarding cell Reynold number option provided in COMSOL post-processing. What I understand is that cell Reynold number is calculated with velocity and length within/from...
View ArticleHow to properly define inlets and outlet in "Rotating Machinery" in COMSOL ?
I want to build a model which requires to couple the mass transportation and rotating machinery of the fluid flow. I trying to approach that using 3 steps: 1. Solve the fluid flow in a stationary study...
View ArticleVelocity Profile in two phase laminar flow
Hi, I am simulating a 3D model in two phase laminar flow with level set conditions. The simulations are ok. But i am not able to see the arrow surface plot of velocity. On setting the symmetry...
View ArticleTwo phase laminar flow
What is the meaning of "symmetry" in two phase laminar flow. Does it mean symmetric boundaries or symmetric flow??
View ArticleTrying to simulate electrical arcing
As the title says, I'm trying to simulate electrical arcing using COMSOL. Specifically, I am trying to use COMSOL to determine whether or not arcing will occur in a high voltage battery configuration...
View ArticleWater infiltration in a closed system
Hi,I have some problem with my model. It is about water pouring from surface of a soil column. The bottom of the soil column is bounded (also the vertical wall). Thus, the air inside soil must be...
View ArticleTurbulent Multiphase Flow in Packed-bed
Hi :)I am simulating a packed bed bioreactor. It is multi-phase & turbulent. (attached file) I am just getting errors with mixture and Euler-Euler. (bubbly is not applicable due to high quantity of...
View ArticleFree surface in liquid flow model.
I have modest experience in using COMSOL, very limited in fluid flow modelling.I've encountered a new type of problem for me, & so far cannot 'get started'; any pointer to similar examples etc...
View ArticleHow to model laminar flow between parallel plates with partially slip...
Hi all,I'm trying to simulate a laminar flow between parallel plates. It's inlet velocity and outlet velocity are set to be the same---4z(H-z)umax/H^2 in x direction (only). The top and bottom...
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