Accessing prior solutions while solving a Time-Dependent Study
I am trying to create a condition for my bioheat transfer simulations that will deactivate blood perfusion effects when the maximum temperature (at any previous time point) exceeds 60 degrees Celsius....
View Articlewhy the scattering cross section calculation result is negative?
Hi, I am doing some calculation with comsol 4.2a, and I manage to do the scattering cross section calculation for the sphere model. Then I use exactly the same model, but change the sphere scatter to...
View ArticleExtract data of a contour at any time step
Hi everybody, In my results I have a contour and its position (i.e. x, y) is changed at any time step. I want to extract data of the location of that contour at any time step . Would you please help me...
View ArticleCurrent at the boundary
Dear User, What will be correct expression for current density in Joule heating module? I have 2D antisymmetric model. I want calculate current at the boundary. So, I need to integrate current density....
View ArticleDensity-limited diffusion
Hi, I'm trying to solve a set of 3 PDEs where one of the diffusion in one of the PDEs is limited by the value of one of the other variables, something like this: ut=... vt=vx*(D*(1-u))+... when I run...
View ArticleWill the increase of the relative tolerance reduce the solving time ?
Dear all, as mentioned in the title, I would know if the change (specifically an increase) of the relative tolerance in Time Dependent solver (but also in Stationary solver, why not) will reduce the...
View Article2D->3D
Hi Everyone, I successfully build a model for a redox flow battery in 2D, but now I tried to convert it to 3D and following error occurs. I have read the others threads regarding this error but...
View ArticleProblem with Neumann boundary condition definition
Hi, I am simulating a Helmholtz equation (using the PDE mode module) with a Neumann boundary condition. Some days ago, we decided to update our Comsol version from 3.4 to 4.0. In the new version we...
View ArticleWhat's the difference between Form a union and Form an assembly?
comsol version 4 In Geometry, there is an interface called Finalize (Form Union or Form Assembly). What's the meanings of Form a union and Form an assembly? Is it like this? For example, when I creat...
View ArticleWhich interface choose for fluid flow with heat transfer
Good day! I would like to ask for an advice. I wish to solve the following problem: I have a plate of a solid material with low thermal conductivity. There is a pipe with cold water inside the plate....
View ArticleStore part of solution for next run
Hi: I have 2D and 3D models of the same experiment which are in the same file. I would like to do two things: 1) Store the solution of the 3D run and store seperately the data from a "cutplane". 2) Use...
View ArticleHow to specify the phase shift in electric currents (ec)
Hi, I try to reproduce the 3-phase cable simulation as shown in www.youtube.com/watch?v=ZCLcbSQB1-Q I used the electric currents physics and time-dependent. How to specify the phase shift among the...
View ArticleFinal Abstract Submission Deadline for COMSOL Conference 2013 Rotterdam –...
Dear COMSOL Users, The Final Abstract Submission deadline for the COMSOL Conference 2013 Rotterdam is Friday, August 23rd! Show the modeling and simulation community what you are working on, and get...
View ArticleCan cut line result be used in simulation?
I am currently using comsol to simulate a concentration lets name it C on a 2D symmetry rectangle. at one point I need to take a boundary value of C, I am wondering if there is anyway I can take the...
View ArticleSaving a file for later assemby
Hi, I want to model geometry of a complicated tool for later studies on Multibody dynamics module. As an start, I have created each part in different files and I have saved them as the mph file....
View ArticleDisplacement between two points
Hi I am very new to COMSOL and I am having trouble with calculating the displacement between two points. I'm using the structural mechanics module and I'm applying a body load to a an object and I want...
View ArticleApplying weak constraints in Darcy's law
Hi, I'm working on vapor intrusion modeling from subsurface into the overlying building. I have a large domain (100m X 100m) and a building (10m X 10m) with 2m basement is locating at center of the...
View ArticleScattering off a gold tip
Hey everyone, I'm having trouble with my model and was hoping someone could help me out. I am trying to model what happens when a frequency of light washes over a small tip of gold. My model is very...
View Articleinduced current in a loop, but with symmetry plane
I'm studying the induced current in a loop of wire from AC current driven in a nearby wire. The symmetry of the fields should allow for cutting the model in half, but I'm not sure of the BC's to use on...
View ArticleDisproportionate Number of Degrees of Freedom
Hi All Using an adapted mesh roughly numbering 2 million mesh elements, the solver calculates based on 14 million degrees of freedom which is outside my RAM capabilities (48Gb). When using a normal...
View Article