Inconsistent Units
Hi, I´m trying to incorporate the following expression on Subdomain expressions: D=0.926*T^2.5/(T*245) the result should be in mm^2/s, but It shows me "Inconsistent Units" even when I try the...
View ArticleModeling flow through a thin channel
Hi, I'm trying to model water flow through a 2D thin channel (8 cm X 2 mm). This is part of my PhD research. The inlet pressure is 1.5 bar, outlet pressure is 1 bar. The walls have a no slip...
View Articleheat transfer simulation
Hi, I am trying to simulate heat transfer of a 3D closed box with a fluid(Nitrogen) inside it and some solid electronic components that are heat sources. Actually I am a little confused with different...
View ArticleCapacitance as a function of frequency plot
As the subject, I would like to know how to make plot of Capacitance vs Frequency. I am using AC/DC module and electrostatics study.. moreover, i have computed using stationary step to plot the...
View ArticlePDE mode in comsol 3.5(a)
Hi I want to know that whether we can use PDE mode in axisymmetric geometries in comsol 3.5(a). I think it is not available for axisymmetric geometries and only exist for 2D geometries. When I select...
View Articlestuck with perhaps the simplest problem of thermal expansion
Hi, I am a newbie to COMSOL trying to model thermal expansion of a hollow copper disc from 300K to 500K. I am unsure of which model I should to use as there isn't any heat transfer. It is a steady...
View Articleto extract only the geometrical information after deformation
Hi,everyone! Recently I met with a problem about how to extract only the geometrical information after deformation, meanwhile I want to discard the material and physical information (such as stress,...
View ArticleFluid-Porous Slip boundary conditon
Hello, I focus now on the flow and solute transportation simulation in the free flow and porous media. There are traditionally one singe formulation, typically Brinkman and two-domain coupling with...
View ArticleExporting data for multiple Cut planes
Hi all, I'm modeling a mixer and I would like to export concentration profiles at different cut-planes along the channel. I can do a single cut plane export with: Defining: Data Sets -> Cut Plane -...
View ArticleStudy options
I everybody, I've been using COMSOL for more than a year now, and up until now I had no need to changing anything in the default solver, but now I do. To be more specific, I work in a huge file which...
View ArticleElectronic Invitation to the COMSOL Conference Boston (Oct 3-5) now available!
Hello, The COMSOL Conference is the place to be for getting the most out of your simulation work and connecting with fellow COMSOL users. Know what's coming up next in multiphysics simulation and...
View ArticleError while Running Simulation
Hi, I started getting this error all of a sudden and it says not enough disk space. I have 128GB of free space and still I am getting this error. Does anyone have anyidea about how to resolve it? Kind...
View ArticleMethane/Air
I am trying to model the mixing of methane and air. Since they are both gases, I am having trouble getting the mixing to work. I would use two-phase flow, level set if this was a liquid-gas interface,...
View ArticleWill change relative tolerance results in quite different results?
Hi, I always encounter the problem that "Failed to find a solution. The relative error (0.032) is greater than the relative tolerance. Returned solution is not converged." Usually, I change the...
View ArticleStructures ignore each other upn contact
Hi, I'm new to comsol, just started using it few weeks ago. I'm building a model of capillaries and white blood cells. I tried to fit a sphere inside a tube and make the sphere expand due to internal...
View ArticleReciprocal of the time steps
Hi, Does any one knows what exactly the reciprocal of the time step means in a transient simulation. How far its value must fall in order to have converged results wrt time. In my simulation it never...
View Articlemesh data
hi anyone can tell me how to get volume of each elements in comsol?, is it possible to get element numbers in comsol?, I hope 'dvol' give the element volume scale factor, from manual I understood its...
View ArticleGravity effect
Hi, Sorry for my newbie question. I'm trying to simulate 2D two-phase flow in porous media. I'm wondering whether COMSOL considers gravity effect when applying Two-Phase Darcy's Law physics. Thank you,...
View ArticleDeformation of liquid droplet
I am new to COMSOL, so I am referencing a work on deformation of liquid droplet impacting a solid surface. I tried to recreate the same model as that work. But I ran into several problems. As I tracked...
View ArticleTime Dependent Analysis of two Coupled Membranes
Hi everyone! I am very new to comsol, so I apologize in advance if my problem is trivial. I have to perform an acoustical simulation with comsol 4.2a. My system is made of two elastic circular...
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