CFD simulations resulting in extreme pressures
Hello! I am doing some CFD simulations on the housing of a radial piston hydraulic motor (the simplified geometry can somewhat be similar to a gear spinning in a confined volume where the cogs are...
View Articleill conditioned preconditioner, fluid in porous media simulation
Hi everyone, I was trying to do a simulation of fluid in porous media. The geometry I had was a channel, with both ends non-porous, and the middle part porous. In the porous part, I was using the...
View ArticleHow to create a No Flux Boundary condition for one of two chemical species
I'm am modeling a fuel cell using transport of concentrated species (tcs) with 2 species, wH2 and wH2O. In the fuel cell there is a boundary where the water (wH2O) is able to pass through but the...
View ArticleAfter Simulation done, the changing between results nodes, takes very long time
Dear all, I am working on microfluidic laminar flow and particle trajectory, which is the second study as time dependent study. The simulation was quite slow ( 12 hours with 69000 DOF) but after...
View Articleparticle tracing
I was wondering if a particle can seal a hole only due to pressure difference without setting wall condition like stick?
View ArticleConvective heat transfer over long duration
Hello, the problem I'm currently trying to solve consists of a coaxial cable (cylinder) arrangement buried in soil, and I'm hoping to get a god estimate of the temperatures of the inner and outer...
View Article3D fluid flow in a pipe
I am trying to model laminar flows being joined as a number of pipes are joined. I also care about the thermal effects, so I need to model the pipes as well as the flow within them. However, I can't...
View ArticleProblem with periodic boundary condition
Hi, i have a problem that i don't really understand. I made some simulation of a square impedance tube to compute sound absorption coefficient. The mode works very well. when i apply a periodic...
View ArticleLaminar flow model with two inlets, one outlet, and a vacuum pump
Hello. I am new to comsol. I am currently trying to model a cylindrical region in COMSOL (Laminar Flow Interface) that operates in the laminar flow regime. I am using one side of the cylinder to input...
View ArticleFlux over time Graph /Plot
I have Richard's equation model with two no flow boundaries on sides of square with top boundary as pressure head at 0.00001 m and bottom boundary as pressure head at 0 m . Model has initial conditions...
View ArticleGrid independence
Hi all, I am simulation hydrogen absorption in a metal hydride using heat transfer in porous media and laminar flow physics. The model is converging fine but when I run on normal and finer mesh I get...
View ArticleTransport in multimaterial geometry
Hello, I would like to model a transport of hydrogen (H2) in a multilateral geometry. This geometry is approximated as 2D in which a flow of fluid contains diluted hydrogen and it is in contact with a...
View ArticleCalculate the energy gain of fluid
Hi we are modelling a fluid across of pipe, inner the pipe the fluid recive a heat flux from a solid, when i calculate the energy gain of fluid =m*Cp*AT is higher than the global evaluation of heat...
View ArticleA beginner's question regarding flow simulation of perforated pipes
Greetings! One of the major tasks for my project is to achieve laminar flow after a diffuser leading from a perforated pressure pipe. The flow inside the perforated pipe is turbulent, the holes in the...
View ArticleThree phase flow problem
I'm getting the following errors when I try simulating droplet separation process. I've attached my file for reference. Failed to find consistent initial values. Attempt to evaluate real square root of...
View ArticleFluid Flow - Liquid Nitrogen
Hi everyone I'm trying to simulate cooling a solid submerged in liquid nitrogen. I've successfully simulated cooling a hot solid submerged in water using both Turbulent Bubbly Flow and Laminar Flow,...
View ArticleBoundary condition is a PDE, rather than a constant!
Dear all: In my model for fluid flow in porous media, I want to set gas pressure as boundary condition at one end of the soil specimen. In the experiment, the gas pressure is applied on the specimen by...
View Articlecell move in a microchannel
Hi all, I am doing simulation about a cell moving in a microchannel. I want to model the cell as a layer of elastic material with water in the closed membrane. Attached please find the geometry. I use...
View Articleparticle deformation througn a contrained channel
Hi there, I am doing COMSOL simulation to see the behavior of a particle flow through a microchannel. There is a area of the channel where particle size is greater than the cross section. So the...
View ArticleTwo Phase Transport PEMFC
Hi, I'm having problems in implementing the two phase transport in the Low-Temperature PEMFC model. Initially, I built a model composed by the following physics: 1. Secondary Current Distribution; 2....
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