particle tracing plot
Hi I have some problem for particle tracing plot. In the particle tracing plot, I guess that the released particle has certain path according to the time. It means, the path of particle at 0.2sec, has...
View ArticleRegarding coupling 3 physics
Dear all, I am simulating power cable exposed to natural convection, i.e. in air. I am using Joule Heating Physics which has by default Electric Currents and Heat Transfer in Solids. But when define...
View ArticleFailed to evaluate expression
I am new to comsol. I have a problem. I repeatedly getting the error message "Failed to evaluate expression". Pls help. I am not able to upload the file as its 56MB.
View ArticleWhy "Tin Melting Front" tutorial don't work with stationary solver?
Hello! There is an interesting question. I study the tutorial model "Tin Melting Front". This is Time depended model as it presented. However, this problem obviously has a stationary solution. So, why...
View ArticleNavier-Stokes Simulation using Coefficient Form PDE
Hi: I need to simulate fluid flow in a triangular duct, but I need to run it on a high reynold number. The problem is that when I run the model using the default "Laminar Flow" physics tab, I need a...
View ArticleGet warnings "inverted mesh element near coordinates"
Hi all, I'm follow the guidance from Ivar to try to develop a simple structure with parameter of surface roughness. However I got the error "Inverted mesh element near coordinates". I have never seen...
View ArticleModeling Laser ablation of Aluminum
Hi everyone :) I use comsol 3.5 to model laser ablation of Aluminum in the following stack - Aluminum/Silicon nitride/Silicon. How to couple the heat transfer equations to the ablation and melting of...
View Article"Internal error in boundary respecting." and "Out of memory during assembly."
Dear All I have two errors in my microfluidic models about "Internal error in boundary respecting." and "Out of memory during assembly.". At first I tried to simulate the flow of the overall 3D...
View ArticleHow to solve the problem of negative concentration
I am a totally new user on comsol. Now I try to simulate the mixing in the microchannel without reactions. I use the laminar flow and Transport of dilluted species. There is a similar example from...
View ArticlePhase change in porous media
Hello, I am modelling a geothermal system, where a porous rock is saturated with groundwater and heated by an intrusion of magma. I have used 'Heat transfer in porous media' coupled with the 'Brinkmann...
View ArticleWeak contribution to levelset interface
Dear all, I would like to add a weak contribution (for surface tension) to a moving levelset interface for the following application: I want to model a fluid with a free surface, on which there should...
View ArticleInertial Focusing
I want to get the projectile of microspheresc in microfluidic chip. I am trying to get a complete solution to Navier and Stokes equations at low (unity) Reynold number. (viscous and inertial ). is...
View ArticleEstimate Hydrulic Tansor
How can I calculate permeability of joint rocks using this software? My parameters are Joint aperture, Joint set spacing, Groundwater viscosity, Dip and Dip direction of joints and assumed that blocks...
View ArticleCouple two transient studies: Using transient flow field in transport simulation
Dear Comsol users, it would be very kind if someone could help me (I spent several hours trying to find a solution). I want to use the results of study 1 (time-dependent flow field) in study 2...
View ArticleMake an stl file a domain for CFD
I need to do a CFD simulation with Comsol. I have an STL file with a mesh describing the surface of an object on which I would like to do some fluid dynamics simulation. As far as my understanding...
View ArticleNegative concentration and strange profiles in microfluidic? help!
Hi everyone! I am modelling a microfluidic device. There's an initial concentration of reagent in the chamber and I apply a flow with nearly 0 concentration at one side. (I put the file at the bottom...
View ArticleAccurate inflow/outflow calculation
Hi, I'm using the Free&Porous workflow, but the question is also applicable to Navier-Stokes. I have an inlet and use NormalVelocity boundary condition which, it seems sets up a Lagrange multiplier...
View Articlewhat is 'fpt.domvar_deff1' in fluid particle tracing module
Hello everyone I want to calculate the dielectrophoresis force by the fluid particle tracing module(fpt). But the equation puzzled me: 2*fpt.rp^3*pi*fpt.er*epsilon0_const*...
View ArticleFlooding with COMSOL
Hello, I want to simulate the inundation of the island due to water rise (as external parameter). Can I do it using COMSOL? If yes, Is It possible to combine it with the model of porous media? regards...
View ArticleThermocapillary recirculation
EDITED Hello, I am a beginning user of COMSOL. Currently, I am trying to create a preliminary model of Marangoni convection, like this one available on the COMSOL site:...
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