auxiliary sweep
Hello everyone, I am simulating a reacting flow with a rather fast reaction. This problem does not converge, and I found out that I should try an auxiliary sweep with a parameter in front of the...
View ArticleSolidworks COMSOL fluid flow (air) simulation
Hi everyone, I was wondering if anyone here knows if COMSOL can simulate Solidworks models straight from import. Here's the scenario: 1. import solidworks model of a pipe with a hollow x-diameter 2....
View ArticleDependent Variables Issues with Heat Transfer in Porous Media
In my model I'm simulating the mass diffusion present in a section of soil directly above an underground coil fire. To simulate the underground coal fire I'm using the Darcy flow, heat transfer through...
View ArticleMoving mesh.
I don't know how to put some conditions in the moving mesh when I set up surface wave. I found an example file whose named 'Sloshing tank' through comsol model library. It is pretty similar with what...
View ArticleModeling a droplet formation
Hello, I am currently trying to model in 3D droplet formation such as T-junction. Attached file is my model. This model was simplified to calculate my comuputer. I want to calculate large model if...
View ArticleNon-isothermal pipe flow in Comsol
Hi all, I am trying to figure out the theoretical background of this module since, instead of using a 3D pipe flow model, it cuts down to 1D pipe flow. 1. Does it mean this module essentially equal to...
View Articleliquid mixing using ultrasound (acoustic module)
Hi and good day for you I'm new in Comsol, my question is, can I simulate the mixing of two immiscible liquid by means of ultrasound wave(20KHz and 500W)? how? for example we have a small vessel (1...
View Articlefinding a specified flow rate in a '3D cut plane'
Hello, I'm trying to do some postprocessing in a 3D fluid channel flow over a fractured hole. The channel is filled with water and is laminar. Here's what I'm trying to do: 1. cut the surface at an...
View ArticleSystem state dependent boundary condition
In simulations of evaporation from porous media convergence issues in COMSOL may arise Consider a porous media is of arbritrary length (1D) and the water movement within is mathematically expressed by...
View ArticleFree convection in oil
Hello, I am trying to simulate free convection in transformer oil, but I find it kinda hard. Its easy to simulate free convecction in gases or water using Conjugate Heat Transfer (Fluid and Volume...
View ArticleConvergence problem ( PID heater controller)
Hi, I have a problem with the convergence of my model. I have this message d'error "" there are 876 degrees of freedom returning NaN / Inf in the matrix rows for the variable comp1.T. the coordinates...
View ArticleApplying a pressure to a boundary
Hello Ivar, Sorry for contacting you directly, but I have limited time and you seem to be one of the most knowledgeable people in the forums. It could just be a quick fix. I am having an issue with...
View Articleon heat transfer from semiconductors and the effect of the surface due to...
i am pretty new to comsol.....i need to simulate and measure the changes in temperature when a coolant liquid flows over a semiconductor surface in an integrated circuit. and also how the surface of...
View ArticleConvergence Problem when using the Periodic Flow Condition
Hi everyone, I'm currently using the Laminar Two Phase Flow- Phase Field(tpf) model in Comsol 4.4. The geometry setup is attached. The problem is when I applied Periodic Flow Condition to the left and...
View ArticleLift- and drag coefficient on rotating cylinder in a uniform stream
Hi all, I'm trying to plot the lift and drag force on a rotating cylinder in a uniform stream (2D) for low Re=100. I've been successfull with calculating/plot the coefficient for the non-rotating...
View Articleliquid mixing using ultrasound (acoustic module)
Hi and good day for you I'm new in Comsol, my question is, can I simulate the mixing of two immiscible liquid by means of ultrasound wave(20KHz and 500W)? how? for example we have a small vessel (1...
View Articlefinding a specified flow rate in a '3D cut plane'
Hello, I'm trying to do some postprocessing in a 3D fluid channel flow over a fractured hole. The channel is filled with water and is laminar. Here's what I'm trying to do: 1. cut the surface at an...
View ArticleHow to solve the problem of negative concentration
I am a totally new user on comsol. Now I try to simulate the mixing in the microchannel without reactions. I use the laminar flow and Transport of dilluted species. There is a similar example from...
View ArticleHow do I model two different fluids in one domain?
Hi, I am new to COMSOL, and am trying to model a microfluidic device that has two fluids, each with a different conductivity. I tried building a geometry with two domains that are a union with an...
View ArticleHelp Needed - Lift and Drag for a Flat Plate, Normal to Flow
I am trying to determine the lift and drag coefficients for a 2-D flat plat ( 0.1 m chord x 0.0166667 m height ) oriented perpendicular to an air flow with Re of 10^4 using the Spallart-Almaras...
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