One boundary with two boundary conditions (Neumann and Dirichlet)
Please help me to understand about this issue. I have a system of two PDE equations with two variables (u1, u2) need to be solved in General Form. On a boundary 1, for example, I set up a Neumann...
View ArticleError Jacobi with user-defined function
I defined a function in Global Definition to describe the graded-index. However, when I used the Solve-Modal Analysis, the COMSOL popped a window to warn error in Jacobi matrix. Plus, I suppose my...
View ArticleHow to Improve Convergence in Natural Convection
I am wondering how I can improve convergence in my natural convection model. It is a simple model; an isothermal aluminum plate in water. The model starts out fine but as the run continues (transient...
View ArticleHow to get final dimensions i.e. outer profile in COMSOL?
Dear friends i want a help in this part. Here, i'm explaining the full problem. # i got the co ordinates of a biological part from image analysis in MATLAB . I plotted those points in the COMSOL (...
View ArticleEuler-Euler Model: reached singularity
I am running a Euler-Euler model and get a singularity error about six seconds into a 12 second analysis. It appears that there is a high velocity flair at an inlet when the singularity occurs. I have...
View Articlefunctionality of time-dependent adaption
Hello, I’m member of a research group at the University of Augsburg which is working on acoustic-wave-simulation in composite materials using COMSOL. Since the problems we solve are extremely...
View ArticleSimulatneous temperature distribution...!
Dear Comsol Users, I am willing to come over to you again, this time with some questions I would like to be enlighted. I've built a 3D heat exchanger (coil) inside a material (cylinder) and with...
View ArticleHow to plot required results??
Dear sir, I wish to create an imaginary plane in required location of my model and plot the results like Maximum, Average and Minimum temperatures at that particular plane. How can I do that?
View ArticleCoupling three physics "variables not solved for"
Hi, I have to solve three different physics together in COMSOL . physics 1-Electrostatics: solving for variable V physics 2-Electrostatics:solving for variable V2 physics 3-Navier stokes...
View ArticleVolume Integration and Surface Integration
What is the use of volume integration and surface integration for the parameters like temperature, pressure and velocity??
View ArticleRunning the simulation for the required time span in more than one times (loops)
Dear sir, My requirement is "Running the simulation for the required time span in more than one times (loops)". I actually do not know the initial values of temperatures of the room that I am going to...
View ArticleHow to output results in MATLAB livelink with COMSOL?
A Finite element analysis was done in COMSOL and it was saved as .m file, so that i could run it in a livelink with matlab. The program executed and i got nothing as output i.e. there were no errors...
View ArticleRunning the simulation for the required time span in more than one times (loops)
Dear sir, My requirement is "Running the simulation for the required time span in more than one times (loops)". I actually do not know the initial values of temperatures of the room that I am going to...
View ArticleCOMSOL Failing at Simple DE?
I've encountered a very simple problem with COMSOL's eigenvalue solver and I was wondering if anyone else has had the same problem. I'm trying to solve the simplest DE imaginable. I'm trying to find...
View ArticleUndefined value found
I had great trouble meshing a geometry. After I refined the mesh and was finally able to mesh it, I clicked the compute button. 78 seconds later, I got this message: Undefined value found. - Detail:...
View Articlebatch file
Hey. How to use batch files. And where is possible to find documentation on this topic. Thank you.
View ArticleError: The file position must be a positive integer
Hello, I am going through the SAR in human head example provided. Everything is completed as per the tutorial. I am trying to solve now. However, I get this error: ==================================...
View ArticleMagnetic Field Simulation
Hi, i'm currently trying to do a mf analysis of the system in append figure. The four quadrangular structures are coils with a external current applied. I defined all the domain's material and added...
View ArticleHow to generate pulsed laser in Bioheat Eq.
For Bioheat equation, there is one parameter which I can input corresponding to laser source, Q_ext (spatial heat source) In this part, I typed the equation of laser radiation below,...
View ArticleHow to restrict the scale of calculation
Well, I'm interested in a model as attached. I'm using the Structural Mechanics Module in order to calculate a deformation at low temperature caused by different thermal expansion coefficients....
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