COMSOL simulation for heat and mass transfer across membrane for membrane...
Hi, For your information, I am developing a COMSOL simulation for the direct contact membrane distillation (DCMD) process. It is actually a process which involve the heat and mass transfer from the...
View ArticleODE simple problem
Hi, I have a two problems. I'm trying to solve simple differential equation in the form of: dA/dt=-k*t*A initial conditions: k=1 A=5e-4 At=5e-4 This equation is describing reaction kinetics. To be more...
View Article4th order pde
Hello everybody, I have 4th order pde equation (Navier sokes lubrication aproximation). As I know I need to make intermediate depended variables of 2nd order. Maybe somebody could tel me where I need...
View Articlehuman head skull stimulation by current source electrods
Hi I am new to Comsol. I have tried to build a simple model resembling human head including three layers of skull, csf and brain using the provided conductivities. I then built a tri-pole electrode...
View ArticleCluster Computing Convergence Plot
Is it possible to view a convergence plot when solving a problem on a HPCS2008 cluster? I know in the log file generated by the cluster that completion percentages are generated. If it is not possible...
View ArticleUnrealistic results in Elasto-Plastic analysis: Thermal Stress Problem
I am modeling a Thermal stress analysis of 3D wire wherein Temperature field (x,y,z) was imposed by using Interpolation function (imported a .txt file). It is simply an Elastic-Plastic analysis....
View ArticleGeneralized alpha settings
Hello everyone Can someone indicate me the different settings for the "maximum time step" and "time step increase delay" when choosing the generalized alpha tims solver? For example, I'd like to have a...
View ArticleConvergence in convective heat transfer
Hi there, I am trying to replicate the model of a published paper about the performances of horizontal micro-fins in natural convection (Mahmoud et al. (2011). Effect of micro fin geometry on natural...
View ArticleWhat would be your ideal COMSOL workstation?
Hello all, I am in the process of building my own COMSOL workstation, and am looking for advice. If you were building your own computer from scratch, what parts would you be sure to get (besides a...
View ArticleCOMSOL Error for Initial Values(RF Module)
I am defining a model with different concentrations of oil and water and trying to measure the heat distribution by using the microwaves. But I obtained the error mentioning Initial values: THE...
View ArticleNo species released when using Transport of Species model
Hi, I am trying to add some tracer to the bulk flow. In Study 1, I am running a Steady air flow, and then in Study 2, I add a tracer to the flow. The tracer is released from a point (a source using...
View ArticleTo demonstrate a "sieve" at the particle tracing module
Hi all, now I'm trying to demonstrate a particle sieve using the particle tracing module. I expected that the particles bigger than the pore size of the sieve could be filtered and stuck on the sieve...
View ArticleHow to transmit solution data between two models?
Hello! How to transmit solution data between two models? I have set up two models as follows. 1. To solve u1 satisfied the PDE, D1(u1)=f1, in the first model; 2. to solve u2 satisfied the PDE,...
View Articlecoupled PDEs
Hello, I want to find the profiles of two fields (u1(x,y) and u2(x,y)) on a 2d geometry with known boundary conditions that satisfy the following equation: [(u2y*u1x-u1y*u2x)^2]x +...
View ArticleFSI Module for blood vessel simulation
Hi, I'm trying to implement a very basic 2D axisymmetric model of a blood vessel (straight tube) using the FSI module as I'm interested in getting a wall deformation profile. The problem is that my...
View Articlestudies with multiples steps
Hi all, there is something so weird with my COMSOL 4.3, when I create a time dependent study with different steps the solution only represents the last step and It is not posible to change the time...
View ArticleProbe plots and plot while solving in Comsol 4
How to have "plot while solving" and probe plots in different windows when solving a simulation? When I simply enable them both they show up alternately in the "graphics" tab, making them useless....
View Articlemagnetic field gradient in 3D return zero!
Hi everybody If anybody knows that why the gradient of magnetic field in 3D models is always zero? I checked the different methods. for example I wrote d(Bx,x) or different component of B and H. Even...
View ArticleHow to use solution as initial value for 2nd study with changed geometry?
Hello Everybody. I’m using comsol 4.3a. I try to use the solution from study 1 (stationary heat transfer) as the initial temperature value for a second time dependent study. Further a new geometry...
View ArticleALE moving mesh + electrostatics force calculation are in conflict
Hello Everyone, thanks for all the support or tips you may give on the following problem. I am trying to couple three different modules, to monitor the displacement of a bubble in a channel in 3D under...
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