Coupled Physics
Hi i'm a beginner and i don't know a lot about multiphysics simulation. I solve a model with drift-diffusion equations (variable of the phyisic: quasi fermi potential FIn) coupled with piezoelectric...
View ArticleNanowire joule heating
Hey, I am new to comsol. I am trying to model temperature profile along my nanowire. My process is as follows: There is a constant current pulse for a few nanoseconds. The nanowire joule heats, with...
View Articlemultiphase flow with moving interface combined with diffusion
I'm working on a simulation of two droplets in air coalescing into one combined droplet in which I want to follow in time the mass transport of a species C in one droplet into the coalesced droplet....
View Articleupdating a nested parametric sweep
Hi I use nested parametric sweep and once in a while after the model has been solved, I would like to add one or two additional values to my parameters to fill the gap between them or increase the...
View ArticleMaking unions, intersections and such
Hello, this is the question regarding the "Internal error in geometry decomposition" message that I'm consistently getting. What I'm trying to build is a 3D RVE of particulate composite (see attached...
View ArticleDifference between "Porous Media and Subsurface Flow" and "Poroelasticity...
I am a little confused by two physical module, the first one is Fluid Flow-----Porous Media and Subsurface Flow, and the second one is Structural Mechanics--------Poroelasticity (Poro). What is the...
View ArticleFSI error : segregated solver
Dear All, I am trying to work with FSI simulation of Blood-flow in an artery using a coupling of the Laminar Fluid flow and the Solid Mechanics Interface.But my solution-progress is stuck around 10% (...
View ArticleMW Equations + Phase Change in 4.2
Hi, I am using microwave heating option of the RF module for heating a mixture of oil and water.Can any body let me know which set of equations COMSOL is using to solve the microwave heating problem? I...
View ArticleTED in MEMS resonator
Hi I am new to COMSOL. I was trying the Thermoelastic damping in MEMS resonator model [it was done on 3.5 but my version is 4.2a] provided by the comsol. Although I get the similar eigenfrequencies but...
View ArticleCan someone help me understand this error?
I need help understanding the cause of the following error:"Failed to compute elastoplastic strain variables" I have received this error numerous times in a few different structural models where I am...
View ArticleDiode example solved but strange
Hi I tried to solve the semiconductor diode example from the model library but simplifying it a bit. In particular, I discarded the rounded corner and just made it a text book like pn-junction. It...
View Articlestop criterion adaptive mesh refinement
Hi, I have a question concerning the stop criterion of the adaptive mesh refinement (adaptive solver) algorithm: In the Reference Guide stop criterion is only described by: “Terminate execution if it...
View Articlehow to model interface position when filling a channel
Hey, I'm quite new to comsol and so my questions are maybe simple to answer - but not for me yet. For my work I try to model a microchannel with 1mm*1mm crossarea and 5cm long, where water is pumped in...
View Articlesolving helmholtz equation
I wish to solve Helmholtz equation for an Axi-symmetric geometry. The problem geometry consists of a excitation source a tube and air box (all rectangles). Is it possible in equation based modeling?....
View ArticleTransient Hot Wire Method
Hi Everyone! I'm new on COMSOL so I don't know too much yet. I need to simulate the transient hot wire method, I don't know how to start with, and I cannot find any example. Could somebody help me with...
View ArticleRegular Meshing
Hi all, I've been asked to create a regular mapped mesh for a cube which has faces of 10 by 10 square areas throughout the whole of the cube. I'm applying a magnetic field to the cube and I wanted to...
View Articledifference in results when the duration of the model was changed
Hi! I ran the same model for a longer time (Rotating Machinery, Laminar Flow module) and the resulting velocity and pressure are different. Which one should I trust? Why does this happen? For the 2 s...
View ArticleHow is the penalty factor used in the penalty method?
I am modeling a transient contact problem using the penalty method instead of the augmented Lagrangian method. How does COMSOL use the penalty factor when the penalty method is being used? I understand...
View ArticleDilute species transport concentration condition
Hi I wonder why the "Concentration" condition in the dilute species transport model is of type "boundary" and not "domain", since its unit is in "Mole/Volume". Why does this make sense? How should this...
View ArticleHow to simulate the dynamic process of the shelled microbubble using COMSOL
We plan to simulate the dynamic process of the shelled microbubble with diameter of 5um and thickness of 10-100nm, which vibrates inside the ultrasound beam with center frequency of 1MHz. There is one...
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