Failed to evaluate variable jacobian - using a step function
Hi every one, Im trying to put a BC (volumetric flow rate) in my model as a step function. But the following error occur: Failed to evaluate variable Jacobian. - Variable: step1 - Geometry: 1 - Point:...
View ArticleMax value of a field and its coordinates
Hello, I know that there have been a lot of posts about this topic and I have read many of them but I am still as dumb as before. I need to find the value of the maximum value of the field in a domain...
View ArticleFluid-Structure Interaction
Hi, There is a sample Fluid-Structure interaction problem given in Comsol model library. In this module, is it possible to specify the deflection of cantilever in terms of relation between y and x, y...
View ArticleHow to simulate the water boiling by Level-Set method
There is a good example simulating water boiling by phase field. I am trying to use the Level-Set method. However, I was frustrated by many times of failure. My problem is how to deal with the...
View Articlebuilding piezo ring projector (electroacoustic transducer)
Hello, I plan to build piezo ring projector, but I don't decide to build it as 2d axis symmetry or entire 3d model. My electrodes would be located circumferentially. 2d model would be problem because...
View ArticleExtracting absorbed power
Hi all! I am currently doing a 2D model where I have an incoming power, and then I have absorption within the material. As a result, I have the value of the intensity everywhere, but I don't know how...
View Articlehi
can anyone explain to me what is geometry linearity and non linearity? what is the different between them? i'm not clear about that... thank you for advanced... :)
View ArticleUse contour plots as geometric entities
I saw in the release highlight video that in v4.3a that you can use contour plots as geometric entities. How do you do this?
View Articlestart comsol server on cluster on multiple compute nodes
Dear, I would like to run the comsol server on multiple nodes, with each 8 cores, on a linux cluster. For this I use the following command in a PBS script: comsol -nn 1 -np 8 -f ${PBS_NODEFILE} server...
View Articledialysis
Hi, I have got the attached model on dialysis process at COMSOL site. I have some questions regarding the solver. As you can see, under the "Stationary Solver 1" there are two nodes- Fully Coupled and...
View ArticlePlot of Temperatures for a Time Dependent Step
Hi, I was running a case last week that included several physics, including heat transfer. Just by chance, I looked at the computed temperatures at the end of a steady state step and again at the start...
View Articlehow create solids
Hi, I imported two objects as .stl files: the topographic surface-imp1 (see figure topo.png) and the top of a geological unit-imp2 (see figure top.png). Finally, I added a block-blk1 (see figure...
View Articleoxygen dc discharge
Hi I have simulated oxygen dc glow discharge for a month,but not success. I use the model of positive_column_2d in the model library and change Ar to oxygen.The reactino and date come from...
View Article3D Multi Turn Coil
Hi, I just started to play with the magnetic physics and try to build a 3D power inductor using multi turn coil but the model won't converge. I am not sure where it went wrong. Can anyone help me?...
View ArticleTime dependent adaptive mesh refinement
Hi I'm trying to make a CFD model where the flow is driven by the motion of the walls. To do so I coupled a moving mesh and a laminar flow model. First I solved a simple geometry using 2D axial...
View ArticleAre all post-processing function only using single CPU core?
Hi all, I'm doing 3D eigenvalue simulations. I noticed that I can used pardiso direct solver to take advantage of multi-core CPUs. However, when I went to the point of post-processing, e.g. exporting...
View ArticleNVIDIA driver 305.93 causing erratic behavior
COMSOL was working great until I got a Tesla NVIDIA GPU. After installing the driver NVIDIA 305.93 I started getting erratic behavior when mouse clicking on the graphics. When I click to highlight a...
View Article[Solved] Selection Left Click
Hello community, I am faced with a strange problem. I just updated to Comsol 4.3 after using 4.2a for a long time. But it seems I can't left-click on an object to select it anymore. I don't know...
View ArticleSwitched reluctance motor - rotor and stator deformation - How?
Hi. I am building a 2D model in which I would like to showcase how the stator and especially the rotor of a switched reluctance motor deforms because of the radial and tangential magnetic force on the...
View Articletime and position dependent reaction
Hello everyone, i am very new to this and not sure which moduls of the comsol software are needed to solve my problem. there will be a phase change with heat production(white box-> black box in the...
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