new beginner
Hello I am new to COMSOl and I'd like to perform a certain task .. I'd like to simulate the electric field distribution( in 2D and 3D) for a point- plane electrode configuration applied on a block of...
View Articleindependent variable derivative in piece-wise function
Good day all, Lets say I am solving a general form PDE for a variable 'u' and I define some piece-wise function in terms of 'u' (i.e. pw1(u)). My question is, it is possible to evaluate the spatial...
View Articleundefined pressure variable error
Hi! I am new to comsol and I created this toy model to play with in order to get a better understanding. The model intends to simulate the rizing air in a cylinder. The cylinder has an inner and outer...
View ArticleEvaluate derived values
Hello, In the Results node, I would like to evaluate several expressions of derived values simultaneously in the same table. For example, I have to evaluate the Surface Maximum of stresses sx, sy and...
View ArticleEigenfrequency analysis in Acoustics Module
Hei, I am performing an eigenfrequency analysis on a simple energy harvester to find the Q factor. I am able to perform the analysis but the problem is that the mode shape looked like what I was...
View ArticleS-Parameters Two port Network
Hello, I am new to comsol. I have attended couple of workshops and now i have a specific problem. I want to calculate the s-parameters of my network but I do not know how do i create this circuit...
View ArticleBuckling of a fixed-fixed beam
I am trying to model the buckling of a fixed-fixed beam while one end has a specific displacement. When I fix a boundary the COMSOL would not let me to define a fixed displacement for that boundary...
View ArticleWeak form for 2-D elasticity
In an effort to learn COMSOL, I decided to model the two-dimensional elasticity equations using the weak form. I was surprised looking through the documentation that there are very few example...
View ArticleReg Error in 2D residual stress resonator -MEMS
When I tried to perform COMPUTE for a set of values of the beam I am getting the message Failed to find a solution. The relative error (0.028) is greater than the relative tolerance. Returned solution...
View ArticleDamped Eigen frequency Analysis
Hei, I am working on calculating Q factor from eigenfrequecny analysis using structural mechanics. I know that Q factor= abs(imag)/2*abs(real) but my problem is when I add damping in the form of...
View ArticleRotating Magnetic Tweezer
Hi, I am trying to model a permanent magnet magnetic tweezers using comsol's rotating magnetic machinery module. I am using a 3d model and am having a number of problems. The main problem i am having...
View ArticleCoupled PDEs in Coefficient form PDEs
Hello to all, I am working on ultrashort pulsed laser heating modeling. Two Temperature Model is used in this model. which coupled with two Partial differential equations. Ce*(d/dt)*Te=...
View ArticleBoundary Loads Piezoelectric Modeling
Hello, I have a question. I am modeling a piezoelectric and I want to apply a load to it to generate charge, current or voltage. I am using the boundary load condition and would like to use the...
View Articleerror limit set
i saw this in Comsol 'Help' menu. 'The default setting is tol, in which case the segregated iterations are terminated when, for each group, the estimated error is below the corresponding tolerance set...
View ArticleUsing Time-dependent vs Frequency study for single DC pulse
Good day, I am modelling a scenario where a single 100 microsecond DC pulse is passed through a coil. Is it better to use a Time-dependent study or a frequency study set to 10000Hz to model the eddy...
View ArticleFSI Module for blood vessel simulation
Hi, I'm trying to implement a very basic 2D axisymmetric model of a blood vessel (straight tube) using the FSI module as I'm interested in getting a wall deformation profile. The problem is that my...
View ArticleMEMS Piezoresistive
Hi team, I hope you are ok, I am working on a simulation of a piezoresistive pressure sensor covered by a polymer layer, to understand the effect of the polymere on the performance of the sensor. First...
View ArticleVariable modifications between solution iterations
I'm developing a transient model using the Livelink interface. The model first calculates an initial solution for the first time window, then I would like to modify the state variable values due to...
View Articleparticle tracing
hello i have just read your question about particle tracing. i know it was send 1 year ago, but i hope still you are interested on it. i have exactly the same problem you had when you tried to compute...
View ArticleContact between sphere and block
Hi, Eventually i want to calculate the friction between a sphere and a magnet. To understand how contacts work in COMSOL i made two identical models, one which is 2D axisymmetric and the other one 3D....
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