Gas mixture flow simulation
Hi everybody, Gas 1 is flowing in my geometry (a round pipe) and I want to inject gas 2 into the flow. My idea was to assign both gases to the same geometry (using pipe flow module twice) and then use...
View ArticleMatrix has zero on diagonal
I have to solve a lid driven cavity (laminar flow) + melting problem (heat transfer in fluids and solids with moving mesh). I was able to successfully implement this in 2D. I have now shifted to a 3D...
View ArticleThermal resistance in non-isothermal pipe flow (nipfl)
Gooday, I'm using non-isothermal pipe flow model and heat transfer in solids physics in order to simulate a bore hole heat exchanger (BHE). the problem consist of a tube modeling by nipfl and a ground...
View ArticleParachute CFD simulation
Hello, I am trying to perform a CFD flow field simulation of a 3D parachute to find its lift and drag. The geometry model is imported from a CAD software as surfaces only (no thickness). I attached one...
View ArticleProblem in 1D EHD simulation
Dear all, I have built a 1D EHD in COMSOL. But it does not work. There always exists an error. Can anybody give me any suggestion? Please help me! My *.mph file is in the attachment. The error is as...
View ArticleInlet pressure boundary condition not allowing COMSOL to converge
Hi, In my simulation (file attached here), I'm modeling a slight variation of the 2D axi-symmetric 'stirrer in a cylinder' situation, which is on COMSOL model library. In my variation, there is applied...
View Articleinertial focusing in microfluidic channel
Firstly，I want to modeling inertial focusing in straight and curved microfluidic channels（may the channel geometry seems like more complicated ）,just...
View ArticleConvective heat flux
Hi, I'm trying to see the heat conduction from the electric power conduit pipe to the soil surrounding the pipe. The square part which I attached as model.png is the pipe and inside. I built two point...
View ArticleA closed pipe
I want to model a pipe has only an outlet, In fact, I changed inlet to wall. How can I define boundary condition for this case? I attached an image, TX
View ArticleStopping the flow in a pipe after a certain time
Hi, I am new to COMSOL and I am simulating the expansion of steam in a a condenser from a cylinder. They are connected by a pipe. The expansion is due to pressure difference. I need to run the...
View ArticleFlow Separation in fluid flow around a sphere
I am new to COMSOL MULTIPHYSICS. I want to find out at which Reynolds number the flow separation starts in laminar flow.How can I exactly find the point of separation ?
View ArticleProblems with STEP FUNCTION
Hi everybody, I have an inlet in a water reactor working in the following way: 10 s on, 80 s off, 10 s on, 80 s off.... -Fist of all, I have built a PIECEWISE (pw1) function (0<t<10 = 1,...
View ArticleFailed to find consistent initial values
Dear COMSOL users! I am trying to model wormhole formation during the acid injection in the reservoir. It is two scale model: Darcy scale and pore scale. I am using 3 physics: Darcy law, transport of...
View ArticleTurbulent to Laminar
Hi, I want to draw a model in which I wish to simulate whether a turbulent flow converts into laminar flow or not.! I have made a cylindrical pipe and at a further distance I have divided the pipes...
View ArticleUnable to evaluate an expression
Excuse me, I am getting an error as Attempt to evaluate real square root of negative number. Function: sqrt Failed to evaluate expression. Expression:...
View Articledifference between Capacitively coupled plasma and AC-DBD
Hello Everyone ! Can anyone help me in understanding the difference between capacitively coupled plasma (CCP) and an AC-DBD? I appreciate your effort and help. Thanks a lot!! Best regards Zaid
View ArticleSimulation of crack propagation using mixed mode intensity
Hi all, I have read 2 following documents that related to crack propagation.www.comsol.com/model/mixed-mod...of-a-laminated-composite-19961www.comsol.com/model/single-edge-crack-988 The examples talk...
View ArticleSolution does not converge when source term is added?
I am trying to solve laminar flow in porous media and vapor domain. The vapor domain is attached to porous media. I use laminar flow in vapor domain and flow in porous matrix in the another domain. The...
View Articlehow to use function defined in the global in inlet condition(laminar flow)
Hey, I m working on laminar flow in falling film. I got the laminar profile with some intial conditions. Now i want to use the profile as an inlet condition.Therefore i created one function V using...
View Articlepermeability
hi i am doing my final work of grade with comsol. I am doing a reactor with porous membrane and a layer of paladium and i have a lot of doubts about to together the physics and get a flow across of...
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