Convergence problem withtime dependent fluid flow with heat transfer
Hi, I am studying a three dimensional model in which the hot air flows through a pipe and the pipe is surrounded by a phase change material. As a result there are three domains: air domain (turbulent...
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 to apply "anisotropic viscosity" in CFD module.
Hi, Dear all. I recently tried to simulate pressure-driven stokes flow using CFD module. In my study, I should calculate the flow behavior with cylindrical anisotropic viscosity. So, the radial,...
View ArticleModeling of diffusion
Hello! I would like to model the diffusion of dopants into a bulk material from a thin layer on its surface . As I understand, in my COMSOL version (4.4) I should use the module "Transport of Diluted...
View ArticleTemperature not continuous at solid/fluid interface
Hi everyone, The case I'm working on is typical conjugate heat transfer. Two tubes are arranged in concentric configuration. The inner tube is heated on the inner surface and cooled by water flowing...
View Articlehow to calculate lift and drag coefficient in k-epsilon model
I intend to calculate lift and drag coefficient over a rotating cylinder in k-epsilon model (2D). But i am facing trouble to compute lift and drag force. Is there any function to calculate lift and...
View Articleweird air flow
Hi folks, I want to simulate an air flow. The real model is as follows: The air is sucked in by a fan and flows through 2 lattices which lie one on top of each other and have a distance of 4 mm. The...
View ArticleAsk help for Infinite Conductivity Fracture
Hello to every one, I am a very new user to comsol environments. I want to design a flow process in Fracture reservoir. I need your help for How to set up anInfinite Conductivity Fracture in darcy...
View ArticleCombining FSI and Piezoelectric device
Hi , i am new with comsol multiphysics. I am trying to combine different physics for my simulation. It involves FSI, piezoelectricity and triboelectricity. Please advise me which physics should i...
View ArticleSPF.rho and mat1.def.rho(P,T)
Dear all, I have a very simple laminar flow model with one inlet and one outlet (that I use to fix the pressure to 0.4mbar). Everything works fine apart from the fact that when I plot SPF.rho and...
View ArticleImporting 3D geometry into COMSOL
Hello, Happy new year everyone! I need help using this software. I want to know how to select my flow area/domain , which needs fluid to flow through my imported complex geometry(say from AUTOCAD). The...
View ArticleCoupling Lam. Flow and Transport of diluted species in both directions
Dear all, my 2D-model combines laminar flow and transport of diluted species. I understand solving the laminar flow part first and then use this solution via flow coupling for the transport of diluted...
View Articleturbulence model
hello, i am trying to build a model in which the 4 cylindrical heat sources are cooled by forced convection. The turbulence model I ues is k-ε model, but when I turn the flow velocity into lower ones,...
View ArticleModelling of a Hydrocyclone
Hello, I'm modelling a hydrocyclone for solid-liquid seperation. I have two inlet pipes placed opposite to each other at the bottom of a cylinder, water is pumped with a constant velocity, it swirls in...
View ArticleFailed to find consistent initial values
Dear all: I am trying to couple two phase flow and structure mechanics together. In case of generating the huge gap between the initial condition and boundary load ( also inlet), I have already include...
View ArticleModelling Room Air Environment in COMSOL
Hi Everyone, I need to define a Room Air Environment in COMSOL, in which I need to measure a Air Pressure at a specific point on the object plane. I am not sure how can I define the Physics for Air...
View Articlemems based capacitive type humidity sensor
Hello I am working on capacitive type humidity sensor in which I've to model diffusion of humidity in polymide layer that will change the permittivity of polymide hence changing the capacitance between...
View ArticleImported Geometry Shows up as a Hollow Block??
Hi all, I am a newbie in Comsol Multiphysics so please forgive my silly question. I am trying to model fluid flow inside a pipe. I made the model using SolidWorks then I realised Comsol doesn't...
View ArticleConvection in a hollow cylinder between solid domains
Hey everyone, I'm trying to simulate the heat distribution of three electrical power cables with a constant load current buried in soil with COMSOL Multiphysics 5.1. The geometry consists of a...
View Articleassign pressure to line geometry in 3D
Hello, I have a question about assigning pressure to a line in 3D geometry. I want to assign pressure of 0 in a line as a well in porous 3D media in Darcy's law module. I tried with pointwise...
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