Boundary condition setting problem for electrode
Hi! I am using transport of diluted species to simulate particle movement in discharge but have some problems with the boundary condition setting for the electrode: the electron move towards the...
View ArticleDEP particle tracing for fluid flow COMSOL 4.3 simulation
Hi, I've tried to simulate dielectrophoresis by using the particle tracing for fluid flow module of COMSOL 4.3, but I' ve encountered some problems with the dielectrophoresis force. I am trying to...
View ArticleBulk velocity on parallel lines
Hi all I have a two layer geometry. On the interface for calculation of mass transfer coefficient I need to Reynolds number how that velocity in reynolds relation for any point is bulk velocity of...
View ArticleSolver Issues
Dear Ivar, I am trying to solve 2D Marangoni effect due to solute evaporation. I never succeeded. Therefore I tried a different system in which Marangoni stresses come into play due to temperature...
View Articlephase field
Dear Ivan My name is Konstantinos Karalis and I am a PhD Student at the National Technical University of Athens. I am trying to work with phase field or level set on a ternary fluid system. Do you know...
View ArticleAbsolute tolerance convergence criteria for flow simulations.
Hey. Normally convergence criteria are divided into a relative and an absolute. Where can I find and set the absolute tolerance for my transient flow simulation. Thank you for your time
View ArticleQuestion on heat transport turbulence model
Hi, I am using the Non-Isothermal Flow (nitf) module and I have a question on the heat transport turbulence model. In the equation given by COMSOL, rho * Cp * dT/dt + rho * Cp * u . Grad(T) = Grad . (k...
View ArticleTime dependent fluid problem
Hi I am trying to model a time dependent flow of a newtonian fluid in 2D. The geometry I'm using has sliding walls which cause a flow to be established. The aim of using a time dependent simulation is...
View ArticleLaminar flow module in Comsol 4.3a
Hi, everyone, I am using laminar flow module in Comsol 4.3a to model Navier-Stokes equation. My question is how I should add the body force term F into the equation? The term F is listed in the...
View ArticleWelcome to a new forum!
Welcome to The COMSOL Discussion Forum. The goal of the COMSOL Community section is to improve the community experience through increased communication, fellowship, and inclusiveness. It is a place for...
View ArticlePoisson Nernst Planck and Navier Stokes equation
Hi everyone, I am trying to simulate the electro-osmotic flow in a nano-channel using the Poisson-Nernst-Planck and Navier-Stokes equations coupling them from the Electrostatics,Transport of dilute...
View ArticleFluid structure interaction
Hi all! I have some problems simulating a "Fluid structure interaction". I start from this model www.comsol.com/showroom/documentation/model/361/ . I have tosimulate the mitral valve of te heart so l...
View ArticlePolynomial Issue with User-defined Variables
I have a 2D rectangular geometry that has porosity and permeability values dependent on x-coordinate. Polynomial expressions are used to define the local porosity and permeability. However, COMSOL does...
View ArticleHow to define a mixture of two miscible liquids at the inlet?
Hello, I have a question about how to define a mixture of two miscible liquids (for instance water and ethanol) at the inlet. My 2D geometry is as follows: I have two parallel rectangles (representing...
View ArticleInternal error in piecewise expression evaluation
Merry Christmas everybody, I was simulating a laminar flow in a heated circular duct with a non-newtonian Fluid. In order to describe the dynamic viscosity I used the non-newtonian power law with the...
View ArticleSimulation of a heated mixer
Hi everyone, In a school project, we are trying to simulate liquid mixed and heaten. We have simulated the heating, which works. However, when we're trying to simulate the mixing, it always fails. To...
View Articleheat transfer in fluids time dependent error
Hi My problem combines laminar flow and heat transfer in fluids. It runs OK in stationary mode. It runs OK also in either time dependent flow or heat transfer . If I try heat transfer+flow in time...
View ArticleFluid flow - solid body rotation coupling problem
Dear all, I am working on a 2D model of a turbine subjected to air and to do this I guess I need to use laminar flow and ale. Also solid mechanics to define a free to rotate connection. What I want to...
View ArticleBoundary condition setting problem for electrode
Hi! I am using transport of diluted species to simulate particle movement in discharge but have some problems with the boundary condition setting for the electrode: the electron move towards the...
View ArticleDEP particle tracing for fluid flow COMSOL 4.3 simulation
Hi, I've tried to simulate dielectrophoresis by using the particle tracing for fluid flow module of COMSOL 4.3, but I' ve encountered some problems with the dielectrophoresis force. I am trying to...
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