Hagen–Poiseuille flow
I would like to use Comsol for a microfluidics project I'm working on. As this is my first time working with Comsol I am trying to simulate a simple problem to compare the simulation with analytical...
View ArticleCement flowing around funky 3D shape and displacing mud
Hi, I have an interesting fluids problem. 3D object in a snug fit inside a water filled tube. Pump heavy cement in one end, will it displace all of the water as it flows around the object or leave some...
View ArticleWhich solver type to use for coupled K-Epsilon and pipe flow model?
I have a heat exchanger model that I am solving with the CFD and pipe flow modules. I am unsure of which type of solver I should use. I have looked at the COMSOL example model 'heat exchanger plate'...
View ArticleFree & Porous Fluid Flow -- Measure of mass flux
Hi All, I am attempting to model a stream bottom seepage collection device, but I getting some strange results. I am starting out fairly simple with no lateral flow in the free fluid, and setting the...
View ArticleUsing strain rate as a variable
Hi All, I am using COMSOL 4.2 to simulate plastic deformation of aluminum via a dynamic-viscosity approximation. The approximation requires strain rate. My question is how do I access strain rate for...
View ArticleMeshing Internal Volume of CAD import
All, I am trying to model fluid flow inside of a CAD object. How do I create a domain inside the object that I can mesh? I have capped all the openings. Thanks, John
View ArticleProblem with meshing
Sir, While meshing my model, I am getting an error message as follows "Out of memory for mesh processing". What does that error mean and what are the correction requirements??
View ArticleDubinin Sorption Model on Dual Porosity System
Hope this message finds you all well. I have a little technical question. I am currently trying to build a dual porosity model using the earth science module of comsol multiphysics 3.5a. However, I...
View ArticleTry converting to triangular mesh on these faces
Dear sir, While meshing my model, only one domain didn't get meshed. And the error shown for a face which is not meshed is "Try converting to triangular mesh on these faces". And, I was not able to...
View ArticleProblem with periodic boundary condtion.
I am trying to implement the advection equation with periodic boundary conditions using DG. I have specified homogenous Neumann flux on all the boundaries and then I have used the periodic condition on...
View ArticleRandom nucleation
Dear all, I am currently involved in a phase change simulation. I have not yet found the way to deal with random nucleation occurring for instance during the quenching : during the transient heat...
View ArticleSharp Fluid-Fluid Interface
I’m new to COMSOL, and I was hoping someone here would be able to help me. I am trying to model fluid displacement in a pipe. I could use the two-phase flow module, but I don’t need that level of...
View ArticleWhat Physics I need for a liquid cooling problem with phase change
Dear everyone, I am totally new to COMSOL. Now I am working on simulation of a cooling system. It is a melted material thrown to another liquid (e.g. water). This may cause phase change of water from...
View ArticleModifying the Fluid Flow Equation System
Hi everybody, Is it possible to change the fluid flow equation system in order to fit a logarithmic function in the derivative? I am currently using the earth science module to model a dual porosity...
View ArticleHeat Transfer Problem
Hi everyone, I found my heat transfer problem is taking too long to solve even in stationary. The problem is about a pair of thin pipes embedded in soil. pipe diameter 25mm, 20m long each. There is...
View ArticleProblem with insulation...
While using the Non-Isothermal Flow (nitf) and Heat Transfer in Solids (ht), I am facing problem with insulation being allocated to the faces that are not insulated. I suppose that I am not getting...
View ArticleHow to enter the temperature that varies with time??
Due to the variation in air velocity, the external temperature varies with time. Can I know how can I input the values using an equation or an excel sheet??
View ArticleMeshing in a thin fracture
Hi, I am trying to generate mesh for 2D geometry with dimensions(fracture-matrix): i) 0.1mm x 0.1m for fracture ii) 0.05m x 0.1m for adjacent rock-matrix Due to smaller fracture width there is dense...
View ArticleHow to incorporate varying temperature with respect to time??
As the ambient temperature varies with time, I wish to add that variation pattern of temperature in COMSOL 4.3a. Is it possible? If possible, how can I add 1. using equations 2. using excel sheet for...
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