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 ArticleNo-slip on interior boundary
I like to solve (Comsol 4.1) Navier-Stokes (incompressible) in a 2D-domain that has an interior boundary (typically a line starting at some point on the exterior boundary and ending at some point...
View ArticleInterpolation Function Help
Good Morning, I'm having trouble using COMSOL's interpolation function, and I was hoping someone might be able to help. I'm trying to load data from a tab-delimited text file. I've followed the...
View ArticleModel heat transfer in block but can't get the solution
I modelled the heat transfer within a block with some air gaps. In the model, heat is transferred by conduction in the solid domain, and in these air voids, convection and radiation are also involved....
View ArticleGas flow into a reactor
Hi. I'm new to COMSOL and am puzzled on where to start. I would like to model the flow of a gas into a reactor. The gas would be at a temperature T1 and the contents of the reactor would be at T2 (T1...
View ArticleHow to plot two or more independent vaiables in one plot?
Hi, I am solving some PDEs and I want to plot 2 or more independent variables in one plot. how can I do this?
View Articlepzt deformed
Dear Comsol, I'd like to calculate the volume formed by pzt to be deformed, when applying a DC voltage. How can I make this calculation in comsol ? Thanks
View Articlecomplete elliptic integral
Hello everybody, I need to compute the complete elliptic integral of first kind and of second kind in a complex Comsol model. I didn't find these functions in the mathematical functions page of the...
View Articledeformed mesh
I'm using moving mesh analysis and piezo solid for simulating a piezoelectric cantilever .. I’m able to get the results only when I use the physics separately. If I combined both the physics and tried...
View ArticleConvection between to domains
Dear reader, I am trying to setup a convection between two domains. An issue I have is that the boundary condition "convective cooling", defines the external temperature (or environment temperature) as...
View Articlecalculating magnetization?
Hi, In Comsol 3.5, I was able to calculate the magnetic moment for an object (in the model below, a sphere) with a constitutive relation B=mu0 mur H, when embedded in a bigger block with B=mu0 H, (ie...
View Articlereacf
I have not found the mathematical formula for the "reacf" operator. What is it? Another issue: When I integrate "Current density norm" = ec.normJ or reacf(V) over an insulating surface, I get a nonzero...
View ArticleParameter Estimations by Inverse Analysis using Comsol 4.2.
Dear Sirs, I would like to have an opinion by more expert users than me. I am facing a problem of parameter estimation by inverse analysis for structural mechanics. More simply, I have to estimate the...
View ArticleNumber of degrees of freedom solved for: 96195
Dear Sirs, I am trying to understand from where the number 96195 comes from. In particular, the mesh I am considering is a tetraedral mesh of a rectangular domain in 3D ( width = 5 cm, depth = 1.5 cm,...
View ArticleModal Mass calculation
Hi Is it possible to calculate the modal mass for a particular mode shape? Can someone please explain how to do it.
View ArticleTime Integral in Frequency Domain
Dear All, I have got a simple geometry: a 1mm thick piston-disc is vibrating with a frequency of 1kHz at 1cm above the closed bottom of a (L=353mm long, Rc=38mm radius) cylinder. The maximum...
View Articlewhat is COMSOL plotting when I surface plot a complex quantity in time...
I'm new to time harmonic analysis. I guess the answer to this question is obvious to many of you that are familiar with time harmonic analysis. I am doing a 2D time harmonic simulation of a...
View ArticleHelp Needed: Comsol solving Error
Hi I am new to Comsol Multiphysics 4.2a. I built a model & try to run it but after clicking compute and it gave me an error specifying the following feature has encountered a problem: -Feature:...
View ArticleWeakly compressible Navier-Stokes Equation
Can Acoustic module be used with Weakly compressible Navier-Stokes equation module to simulate the plate's natural frequency due to sound wave under fluid flowing over it?
View ArticleHow to apply ac voltage
Hi all I want to apply ac voltage(using piezoelectric excitation) to an accelerometer to perform transient analysis. I have tried the SPICE circuit editor, but it supplies only dc voltage. Is there any...
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