time dependent study
I am trying to model a countercurrent shell and tube heat exchanger like geometry that involves heat tranfer coupling and also reactions. I am getting the results for steady state simulation but when i...
View Article"Failed to find consistent initial values"
On a 2D unit square domain with an laminar flow model (incompressible, rho=1, mu=1e-2) and two sets of periodic flow conditions (i.e. both horizontal and vertical) I am trying to get a time dependent...
View ArticleCalculate base pressure of Ahmed body
Hi everyone , I was working on the Ahmed body example available in the website. Does anybody have an idea on how to calculate base pressure at the back the body? Thank you. Best Regards, Sachet
View ArticleSetting up 3-d Navier-Stokes using weak form pde
Hello, I am trying to set up 3-D navier-stokes equation for a fluid confined in a box, using weak form PDE , instead of the comsol predefined fluid flow module. I eventually want to make one of the...
View ArticleProbability density function (PDF) of velocity
Hello everyone, I want to know how to plot the Probability density function (PDF) of velocity in Comsol. And how to normalize the velocity using max value, is that spf.U/max(spf.U). I used it but it...
View Articleweak constraint or pointwise constraint
Hello, I would like to have ur opinion for this situation: I wish to constraint the (fluctuating) pressure to an average value of 20 [constraint expression: aveop1(p)-20] at the inlet boundary while...
View ArticleParticle Tracing: Change of Charge on Wall hit
Hello, I have a simulation of a charged particle with mass in an electric field. The particle movement is generated with the subnode electric force. Where i need so help now is following: The charge...
View ArticleTime Dependent Study of an Airfoil- Lift Coefficient
Hi, I am trying to learn how to calculation the lift and drag coefficient of an airfoil running a time-dependent study. Below are the boundary conditions. Re ~2000 Inlet- Inlet U*step1(t[1/s]) Top and...
View ArticleFluid Flow, axial problem
Hey, There. I am a new user to Comsol Multiphysics. My goal is to simulate a fluid flow through a cylinder and then compare the results with some experimental ones. This fluid is non-newtonian and...
View Articleperforated verticle well
My project is to create a perforated well and inject particle with fluid in it to see how many particles can seal perforations. And I already finished model but can not get a valid result. I have no...
View Articleparticle tracing with Darcy's law in perforated well
My project objective is to see how many particles flow into perforation. And I just built up the model for Darcy's law part, but i don't know how to release particle into well without a Inlet...
View ArticleExtruder screw torque
Hi all. I made a model of the screw of an extruder and I would like to estimate the torque needed to extrude a polymer melt of a certain viscosity but I cannot find anything about it besides the number...
View ArticleModeling of contact in fluid structure interaction FSI toolbox
Hello community! I use FSI toolbox for modelling of vocal fold vibrations. The model is 2D consisting of a fluid domain (glottal channel) and a very compliant solid domain (vocal fold) (picture...
View ArticleHow to couple two components with two different physics in one model? Fluid...
Hello community! My 2D model consists of two components and two different physics . The first component is "Solid Mechanics" and the second "Laminar Flow". Unfortunately, "Fluid Solid Interaction"...
View ArticlePressure boundary conditions
Hi everyone, I want to simulate a duct flow in which an unsteady pressure boundary condition is to be specified at inlet and constant pressure boundary condition at exit of a simple straight...
View ArticleSetting pressure
I want to study flow in pipe I want to set v = 0.05 m/s AND p = 5 atmat the inlet How to set them both? I mean, under laminar flow -> inlet -> boundary conditions I can choose one or the other,...
View ArticleProbleme with integration results
Hi, I'm using Comsol 5.2 for fluid mechanic. I designed my tank in 2D and i need to know to nominal residence time of the liquid inside. In order to do that, I put a tracer coming from the inlet and...
View ArticleHow to prevent fluid mesh from degradation in fluid - structure - interaction...
Hello community! I use (fsi) module for modelling of vocal fold vibrations in 2D. At certain conditions the solid (vocal fold) deforms the fluid mesh too much resulting in mesh collapsing /...
View ArticlePROBLEM: Nonlinear solver did not converge. Rotating Machinery
I am trying to simulate a stirring reactor, following the instructions of tutorial "Laminar Flow in a Baffled Stirred Mixer", but with some differences: - The impeller is a turbine - Viscosity of fluid...
View ArticleMaterial Properties
1. How do I know which expression Comsol is using for a particular properties? For dynamic viscosity it shows eta(T[1/K])[Pa*s]. But I want to know the expression. 2. For moisture air, does comsol take...
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