Navier and Pressure acoustics equations (Conditions at same boundry)
Hi all, I am modelling the Acoustic-Structure interaction in PDE module. For the acoustic part, I have used the general pressure acoustic fieild ( only p as variable) (PDE1) and for the solid part...
View ArticleHow to use the output (solution) of one boundary in a model as the input...
Hi, everybody! I have a question about the boundary settings in the CFD module. I built an open channel and calculated the fully developed turbulent flow. Now I want to build another channel, which has...
View ArticleTube diffusion
Hello all, So I have flow through a cylinder, and want to inject some sort of dye into it. I made a cylinder, and then extruded a circle on the edge to simulate the injection point where I will have...
View Articlevolumetric shrinkage
Dear all, I have a question regarding the setting of initial volumetric shrinkage rate of a geometry. I want to simulate the polymerization process, during which volumetric shrinkage happens when...
View ArticleDAE is structurally inconsistent - Induced current in coil
Hello, I am just starting to use COMSOL (4.3b) and I have encountered a problem while modelling. I am modelling two identical multi- turn coils where from one is excited by sinusoidal voltage source...
View ArticleField Effect Transistor(FET) Design
Hello Everyone. I want to Design Field Effect Transistor(FET). I want to measure I-V characteristics,capacitance,charge and some device physics phenomena. I have already tried but not realizing how to...
View ArticleEarly Bird Abstract Deadline *TODAY* July 5th: COMSOL Conference 2013 Rotterdam
Dear COMSOL users, Today is the Early Bird Abstract Submission Deadline for the COMSOL Conference 2013 Rotterdam. Do you have any work using COMSOL you would like to present? Already I have received...
View ArticleLocal current density
Hi, I am working on a simulation of a redox flow battery. I used the redox flow battery model COMSOL provided and edited it a little. I don't understand it fully and what puzzles me the most is that...
View ArticleMaxwell Equation
Hey! I am wondering if it is possible to solve the Maxwell equations with Comsol 4.2a and if yes, which module do I need for this? I found a description of the Maxwell equations in the Users Guide, but...
View ArticleModelling of cryocooler in COMSOL
Hi, I would like to model a heat extractor/cold stage in cryocooler in COMSOL. The cold stage of the cryocooler extracts heat from the attached mass through conduction. The cold stage maintains cooling...
View ArticleProblem with semiconductor device simulation using COMSOL version 4.0
Hi, I am new to comsol. I am trying to learn how to use comsol version 4.0. Since I am interested in semiconductor devices simulation, I downloaded two models ( mos_transistor and semiconductor_diode)...
View ArticleModelling nanotube
Dear all, I would like to simulate the influence of fiber orientation of CNT (Carbon Nano Tube) on some properties, like thermal conductivity and mechanical properties. Please feel free to contact me...
View ArticleNaN on surface integration
Hi I get a NaNon surface integration of a cut plane but if the integration is on a boundary on the same plane the results are good. Cut planes are easy to define after running the model, Is there a way...
View ArticleCould you please tell me the name of the variable for time steps in comsol?
Hi I am working in comsol 4.2a version for hydrogen storage system modelling. Could you please tell me the name of the variable for time steps in comsol?
View ArticleHelp understanding detailed solver log and time-step size selection
Hello Everyone, Could someone please help me understand what is happening in this excerpt from one of my solver logs? I'm trying to understand what exactly the non-linear solver is 'thinking' so that I...
View ArticlePacked bed mean field model
Hi, I am trying to solve the time-dependent concentration profile in a packed bed using the mean field theory rather than the whole CFD definition of the problem. The mass giving rise to the...
View ArticleCalculation of a magnetic field caused by a current density
Hello everyone, I am very new to Comsol Multiphysics. I have created a quadratic conductor loop (height, width and depth) in 3D and have applied a magnetic flux density to it. By using a certain...
View ArticleChanged environment from air to water doesn't alter electric field
Good afternoon, I have two electrodes set apart several microns, with their voltages set to p/m 5 V, and I'm measuring the electric field norm between the two tips. I want to see what would happen to...
View Articlesingularity error
Hi, I am trying to solve a time dependent, 2D, multiphysics problem using "Transport of Diluted Species" and "Electric Current". In my model there are basically 5 domains in series: at all of them and...
View ArticleCalculation of the Magnetic Field generated by a Current
I have a 3D cylindrical wire, surrounded by air. I want to apply 1V across it. I want COMSOL to: - calculate the Current (known the resistance of the wire); - calculate the Magnetic Field generated by...
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