Natural Free Convection
Hello, I'm attempting to model the temperature rise above ambient over the period of one day within a sealed concrete trough buried in soil with its top exposed to outside air. I have successfully...
View ArticleForced external convective cooling
I have what must be a stupid question about cooling by external forced convection. I'm trying to model a metallic object that is locally heated on one surface and that will be cooled on the other...
View ArticleNavier-Stokes Simulation using General Form PDE: The Continuity Equation
Greetings all. I am working to solve a standard fluid flow problem (e.g. flow in a pipe as a start) using the General Form PDE interfaces instead of the Fluid Flow built in GUI. I am able to define a...
View ArticleNACA 0012 Airfoil with Spalart-Allmaras turbulence model
Hello, I am new to COMSOL and I thought I would start with a relatively simple model: a NACA 0012 airfoil at 0 angle of attack. The domain is small and the mesh resolution is relatively coarse to get...
View ArticleCement flowing around funky 3D shape and displacing mud
Hi, I have an interesting fluids problem. 3D object in a snug fit inside a water filled tube. Pump heavy cement in one end, will it displace all of the water as it flows around the object or leave some...
View ArticleMovement of air due to thermal expansion
Hi everybody! I'm trying to simulate the movement of the air in 2D and I only get errors. I use two physics: laminar flow with heat transfer. I've created a square full of air and I put easy boundary...
View ArticleSurface tension as a variable
Hello all, I have a general question about surface tension in COMSOL. Can surface tension be assigned as a dependent variable? More importantly, can it vary in time AND space? Or be assigned as a...
View ArticleMeshing Air
I'm new to 3D COMSOL and I have the geometry for a chamber that will have air running through it while it performs its function. I am easily able to mesh the geometry, but I'm having problems finding a...
View Articlefluid-structure interaction and fluid-fluid interaction
Dear all, I am trying to solve a problem and I would be very grateful if you would help me. I am very new in comsol, and I also don't have a background in the matter of fluidics. My structure could be...
View Articleparticle tracing module: size distribution function
Hello, I would like to simulate the trajectoires of polydisperse particles in a gas using the "Particle Tracing Module". In order to simulate particles of different sizes, I created an "Interpolation...
View Articleboundary condition that depends on the position
good afternoon I need to enter a boundary condition in Heat Transfer that depends on the position, what should I do? thanks
View ArticleCreate Probing Surface then Surface Integrate over it
Good evening Ladies and Gentlemen! I'm working with a 3D fluid flow model, and I want to find the mass flow rate through an arbitrary cross section of the flow. How can I create a surface that can then...
View ArticleSolving a 4th order PDE: how to specify boundary conditions
A fourth order PDE like the biharmonic equation: ∇^4 w = 0 can be placed in Comsol's standard forms by writing u = ∇^2 w, so that we have system of equations:∇^2 v = w∇^2 w = 0 where v = v(x,y) and w =...
View ArticleHow can I simulate this problem??
I'm new to COMSOL, I want to simulate multiphysics(flow rate and electric field) but have some problem about meshing geometry. I use ITO electrode and water contain in the microchannel. ITO thickness...
View ArticleFind Cross Sectional area perpendicular to an axis at every point
I have a variable diameter hose and I want to find the mass flow through this hose at every point. There are no bends in the hose except to change its diameter so the hose's central axis is in a...
View ArticleTotal Mass and Mass Flow Rate discrepencies
I have a pipe that flows air through a porous media. I calculated the mass flow rate by doing a surface integral across my inlet and outlet. I put fp.rho*v in the integral expression box (where v is...
View ArticleConvergence problems with non-newtonian power law fluid
Hi, I'm modeling fluid flow through a microfluidic bifurcating network. Among other things, I am calculating the volumetric flow rate for a given applied pressure and comparing it to experiment. The...
View Articleflow boundary conditions: periodic velocity fall and normal velocity zero
Hello, I am attempting to simulate a 2D flow of a suspension of solid disks on a square lattice. To reduce the computational expense of this simulation, I'd like to consider shear on a single disk at...
View ArticleVariables
Hi everyone, I have a simple question for you. If I have a variable 'D' , coeficient difusion, depends to temperature (T) with the expression D(T)=0.29*T. the range of temperature is (900 kelvin to...
View Articleparameters
Hi everyone, I have a simple question for you. If I have a variable 'D' , coeficient difusion, depends to temperature (T) with the expression D(T)=0.29*T. the range of temperature is (900 kelvin to...
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