Comsol Definition and 223 Threads

  1. A

    COMSOL Moving Mesh - Can you see it before you compute?

    I'm using COMSOL 4.0a. Whenever I apply a free tetrahedral mesh, I can see it on the structure immediately. However, now I need to use a moving mesh to combine the results of structure deflection and fluid flow. I cannot get the solver to compute without errors. Am I supposed to immediately...
  2. M

    Simulating Tunneling Current in COMSOL for Device Modeling

    hi friends i have a question about the physics of the comsol How can i simulate the tunelling current in comsol i mean which physics should i use i'm using COMSOL 4.2 please help me
  3. U

    How to define a value that is evaluated through iteration in COMSOL 4.0

    Hi, Here are the details in as concise a manner as possible: 1. I'm using In-compressible Navier Stokes Module in laminar flow, time dependent solution. 2.I have a rectangular region in which I have some fluid. 3.there are cilia inside the fluid, which move with a time and space-varying...
  4. S

    Need help in comsol multiphysics

    Hi guys, i simply don't know how to start tis thing with... please help... P/S : pls find the attached.
  5. S

    Comsol 4 Plasma Module: Temperature Limitation?

    I'm using comsol 4 for plasma modeling but I've read that this module is just for low temperature plasma, does anybody knows the temperature limitation of the plasma in this module? I mean how much is the upper limitation of plasma temperature?
  6. H

    Help with COMSOL - Turbulent flow & Heat transfer Impacting Jet in Low-Re

    Hello I am trying to validate my model by comparing a simple axisymetric 2D impacting flow of air on a surface. The geometry is simple: a cylindrical (diameter d=26.5e-3[m]) jet of air (debit Speed Ud=13.46[m/s]) is impacting a surface at distance H=0.2833[m]. Flow temp is Tj=20°C Wall...
  7. A

    Simple (macroscopic) Cantilever in a Fluid with COMSOL

    So I feel like this should be a simpler problem than most with COMSOL... I have a simple cantilever (anchored at one end) with a force at some point source which is making it vibrate at some frequency. This is a macroscopic cantilever, so you can ignore viscosity (and most of the other Navier...
  8. C

    Comsol Modeling of Convection in Glass Optical Fiber

    I need to develop a simple model in Comsol, but I have no experience with it. I need to see what the convective currents and velocity fields are at certain temperatures in a glass optical fiber. I have the information about the fiber and its dimensions. The fiber is going to be at around its...
  9. N

    Heat transfer in fluids, Comsol 4.0a

    Homework Statement hi there, I'm working on an annealing furnace. ingots are warmed up in the oven. I'm doing this with a finite elements method called Comsol Multiphysics. This is a pretty complex software program. Can someone please help me with this part of ComsolHomework Equations it is...
  10. O

    COMSOL example model results do not match with Mathematical Model

    Hi! I started to look into freq response analysis of a cantilever beam using COMSOL. Luckily COMSOL already has an example model "Model Library>> Structural mechanics module>>Dynamics and Vibrations>>rotating blade". While not changing anything in the model and with Omega=0 and Cloris =0, I get...
  11. I

    Solving 16 PDE's at once with COMSOL. (source terms are unknown)

    Hi all: The solution to my problem requires solving 16 PDE's at once. This shouldn't be hard - but you'll know what my problem is in a minute. The 16 PDE's : ∂/∂t (I+i) + Kn*μi ∂/∂x (I+i) + I+i = I0 ∂/∂t (I-i) + Kn*μi ∂/∂x (I-i) + I-i = I0 for i's ranging from 1 to 8. That comes...
  12. F

    Creating Two Coils with Different Axes on Comsol 3.5

    Hi, I am trying to create two coils with different axes on Comsol Multiphysics 3.5. I use the 2D axisymetric mode but it allows to create only coils with the same axe. Can somebody help me ? Thanks in advance.
  13. S

    Someone can help me with Comsol multiphysics?

    Hello everyone! I'm a new entry in thi forum and I need some help with Comsol multiphysics. I'm creating a model of tsunami waves propagation in a defined domain using the PDE interface. I ve not problems in stationary case, but when I try in time dependent case Comsol give me the error...
  14. J

    How to Couple Two Modules in COMSOL?

    Hi, I want to couple two different modules of COMSOL. For example u is the solution of Module 1 and I want to give 0.95*u+a as subdomain settings parameter in module 2. Here a is a vector. I have succeeded with u and 0.95*u to use as subdomain settings parameter of module 2 but when I add a ...
  15. P

    Induced current problem in COMSOL

    Hi everyone, I'm working on COMSOL's ac-dc module and I'm trying to find the magnetic field which is created by an electrode pair (dipole). The working environment of the pair has nonzero conductivity and relative permittivity. I first found the current density between the electrodes in...
  16. M

    What Does COMSOL Error 6250 Mean?

    Hi all, I'm trying to run an eigenfrequency analysis on COMSOL. I have the geometry (a simple square plate fixed in one side), the material (aluminium alloy 1050) and the mesh. However, when I run the solver, I find the famous error 6250. What, exactly does that mean? Thanks in...
  17. C

    COMSOL Natural Convection Thermosyphon Convergence Problem

    Hello, I am having some problems with COMSOL multiphysics 3.5a. I am using 2D weakly compressible flow with general heat transfer and am trying to model a natural convection loop. The Approach I have taken is to use properties of the material for a certain range of temperatures to...
  18. W

    How can I simulate a helix coil with current in COMSOL Multiphysics?

    Hello ! I am using Comsol Multiphysics in order to simulate the eddy currents in a damaged/cracked steel circular rod, with a helix coil surrounded it and thus creating the alternativ magnetic field. Actually, I am having a lot of problem in modelling it, mainly because I am new in using...
  19. F

    Simulation of a double layer capacitance and a warburg impedance with comsol

    Hallo, i'm trying to implement a comsol simulation of a impedance spectroscopy experiment. But unfortunatly I'm an absolut beginner in Comsol and i have many problems with this work. First of all i want to say that I'm using the AC/DC module, more precisely the transient analysis. At the...
  20. G

    Experimental data interpolation in COMSOL

    Here's a question for the COMSOL whizzes: I'm using the COMSOL 3.5a Diffusion Toolbox. I have a 1D reaction-diffusion model that is controlled by a catalyst. The spatial distribution of catalyst along the 1D space is independent of the other chemical species and I have data for the...
  21. S

    Comsol - Negative Concentrations

    Hello All - I use COMSOL in the context of groundwater (Earth Sciences Module). I have run across a problem where I am representing, instead of a point source of pollution, a quadralateral geometry (2D) pollutant source (constant concentration source). COMSOL is constantly computing negative...
  22. T

    How to Troubleshoot Error 6262 in Laser Simulation Using COMSOL?

    Hey I am trying to create a comsol model to simulate laser forming using comsol. As a starting point I am using the heating with a moving laser tutorial and adapting from there. The first stage is to model the beam modes. I the tutorial the beam is treated as being infitesimally thin and is...
  23. J

    COMSOL: Periodic inlet flow rate in a pipe

    Hi all - I would like to add a periodic inlet flow rate (Q(t) over an entire period T) as a BC in COMSOL. Does anyone know how to do this in 2D axisymmetric Transient Navier Stokes through COMSOL? I'm aware of the periodic boundary condition option available, but really just don't know how to...
  24. F

    Solve COMSOL Spring Deformation with Variable Constraint | Beginner Problem

    Greetings. I'm new to COMSOL and am in the stage where I know what I want done, but I just can't get the software to do it. Suppose I model out a metal spring, and fix one end of it in place. I want to pull on the other end, and then plot some value relevant to the deformation of the...
  25. J

    How Can I Resolve Memory Issues in COMSOL for a Complex 3D Model?

    I'm running out of memory on my model help! 3D not axisymmetric! Pictures of geometry and mesh attached. Any recommendations on how to make this possible? This is volumetric flow through a cylinder with a thin membrane attached that is porous and utilizes brinkman's equations.
  26. P

    COMSOL two phase flow with slip boundary condition

    Hey all, I am try to model a problem in which one fluid (of known properties) sits on top of another fluid (with different properties) and there is an imposed slip boundary condition at the interface. I'm wondering if COMSOL has a Slip boundary condition that can be readily used or if...
  27. L

    Solving COMSOL Particle Tracing Problem with Boundary Coordinates

    Hello all, I have a small problem with COMSOL. I am trying to use the particle tracing feature, more precisely I want to use the boundary coordinates to specify where are the points from which to trace the electrons. From what I understand in the User's Giude, the Boundary Coordinates feature...
  28. D

    Photonic Crystal Fibres and COMSOL

    Hello everyone, I am trying to understand COMSOL 3.5 and I am interested in Photonic crystal fibres and tapered optical fibres. First of all, could you please tell me what is the background of the layout? When you create a design/object, the rest area is air or I need to define another object as...
  29. Y

    Calculating Transmission of Electromagnetic Wave in COMSOL

    Hello All, I have a fundamental Comsol question that maybe you can help me with. If I am in say a 2-D In-Plane TE Mode. I am inputting a wave that will propagate left to right. What is the best way solve for the resulting field that is transmitted to the right boundary, regardless of what...
  30. A

    Importing form Proengineer to Ansys and or Comsol

    i want to import a designed geometry to ansys or comsol from proengineer but i can't. (ProE Filetype:*.prt) in ansys: it gets no error but continues processing and becomes not responding... in comsol: it says" Internal error translating CAD model Output file could not be saved"...
  31. J

    (Biomedical Engin.) Fluid flow through a semi-porous membrane (COMSOL)

    Hi all - I have a problem that I'm probably going to model in COMSOL and would love to hear some ideas on how to get the proper BCs. Attached is the picture from Truskey. Essentially, the problem consists of removing waste (water) from the membrane tube at a rate of ~ 1 mL/min with a pressure...
  32. K

    How to Input a Time-Dependent Function in COMSOL for Heat Flow Simulation?

    Hello, I wish to model with Comsol a simple situation: a plasterboard undergoes locally with one 3 ms duration a very short flash (Dirac) and I would like to see the evolution during the time of the wave of heat through volume. The problem it is that I do not know how to enter a function...
  33. A

    How can COMSOL be used to model convection in a room with a radiator?

    Hello! thanks in advance for any help you can throw my way! I am in my masters year of an Acoustical Engineering course in the UK. We have been set a group design project to with essentially setting up a forced convection cycle in a room in order to redistribute the heat from a radiator and...
  34. M

    How Do I Begin Solving a System of PDEs with Comsol?

    Hello! I have to solve a system of PDEs with Comsol and do not know where to start ... This is the system: &u_{,x}+v_{,y}=k y+h x\ \ \ &in\ \mathcal{A} v_{,x}-u_{,y}=k x-h y\ \ \ &in\ \mathcal{A} u n_x+v n_y=0\ \ \ &on\ \partial\mathcal{A} \mathcal{A}\ in\...
  35. A

    COMSOL - 2D axial symmetry for Light Diffraction

    Hello, I would be grateful if someone could comment on my problem. I am trying to simulate diffraction of optical wavelength on a sub-wavelength aperture (aperture diameter/wavelength < 0.1). What I want to achieve is: - simulate a geometrical model with an aperture of 15um diameter -...
  36. C

    Problems using radiative heat transfer in Comsol

    Hi everyone. I am starting using Comsol modeling the temperature field of a buried cable installed into a PVC duct (2D problem). I have already solved the problem considering heat transfer by conduction. To do this, I have used the Electro-Thermal Interaction Application Mode (Perpendicular...
  37. G

    MATLAB Comsol w/Matlab: CLI vs GUI issues

    Hi all - I've been working on some code in Comsol w/ Matlab that works fine on any machine I run it on - so long as I run it through the Comsol w/ Matlab GUI. No matter which machine I run it on, the program fails if I run Comsol w/ Matlab through a CLI. Specifically, the geominport()...
  38. Y

    Why is my COMSOL solution not converging?

    Hello, I'm a 2nd year student, and I'm trying to get to know COMSOL. I'm starting off by solving simple problems with the incompressible Navier-Stokes model, but I keep having trouble with the convegence of the solution. I keep getting the following error: "Failed to find a solution: The...
  39. R

    Looking for a COMSOL or ANSYS model/tutorial (for the design) of a solenoid

    Hello, I've been attempting to learn how to use COMSOL and ANSYS to create and model a simple solenoid (iron core, 1000 turns of 26 AWG Cu wire, 1 Amp, 0 Hz etc), ever since I realized my Department always had a license to both packages :rolleyes:. I've done this using FEMM, and fairly...
  40. S

    STRUCTURE-FLUID interaction (and not the contrary) with Comsol

    Hi, I've got a strange doubt.I model an elastic diaghfram that move water in piping system (a simple pump) so I've got used the 3D FSI multiphicis. Note that in Comsol's examples is the fluid that move the solid structure: i use the same procedure but for the opposite case. I create a simple...
  41. J

    Help, in comsol how to set a perfect plane wave (3D)?

    Hello everyone, I am recently doing some 3D scattering simulation. I use a plane wave as the illumination field,specifically i set a cubic configuration surrounded by PML. I chose one interior boundary and set it as Transition Boundary Condition and set the Ex=1 (x-polarized plane wave...
  42. Y

    Parametric Sweep Analysis in Comsol

    Hi all; I want to run a parametric Sweep analysis and I want to store the temperature value at just one point in the geometry. Is there anyone to know how to do that ?
  43. K

    COMSOL Meshing Help - Solving Large Scale Mesh Problems

    Hi Everyone! I hope someone here can help me with a meshing problem I am experiencing in comsol. What I have is a model which has large scale differences (Ranging from the mm range to the nm range). It seems that with these differences in scale, the free meshing engine has a hard time meshing...
  44. R

    COMSOL Help: 3D Electromagnetics Wave Propagation

    COMSOL help- very URGENT Hi there... Can anyone help me to model the wave propogation through a block of material using the 3D electromagnetics application mode in comsol? I want to simulate the attunation in the intensity of wave when it travels through different materials like Si, Ni...
  45. M

    Using PDE Mode in COMSOL to Model Temperature Change

    Hi everyone, Can anyone explain how to use the PDE mode in COMSOL Multiphysics? I used the heat transfer package to model a piece of copper undergoing a change in temperature from 6 Kelvin to 300 Kelvin. Now I want to check to see that I can get the same results with my own equations. I don't...
  46. K

    Comsol Nanoscale Meshing Problem

    Hi Everyone! I hope someone here can help me with a meshing problem I am experiencing in comsol. What I have is a model which has large scale differences (Ranging from the mm range to the nm range). It seems that with these differences in scale, the free meshing engine has a hard time meshing...
  47. N

    Finding Velocity from Force, Comsol Multiphysics (transient)

    Hi, I am using Comsol Multiphysics to model a magnetic plug surounded by water in a tube. The plug interacts with a magnet and a force is induced. Since I am using the ALE moving mesh option, i have defined the boundaries of the geometry to move with the velocity of the plug. This...
  48. S

    Modeling of resistance in a rectangular sheet with COMSOL

    Hi, I have got a simple problem which makes me struggle. I have a rectangular thin conductive sheet (2D) of width w, height h and conductivity suspended in air. I would like to calculate with COMSOL/Femlab the electrical resistance between one of the corners of the conductive sheet and any...
  49. C

    A liquid/Gas simulation with Comsol Multiphysics

    Dear Friends ! I would really need Your help. I am currently simulating the temporal development of an interface between liquid and gas, by using Comsol Multiphysics. The problem can be simplified in terms of a rotating central liquid pick up (a small rotating cylinder endowed with an...
  50. B

    COMSOL band structure of photonic crystal waveguide

    Setup: I'm trying to make the band structure for a planar photonic crystal with finite thickness, i.e., a quasi-3D problem. I only want the x-direction band structure. So, I'm using variable floquet periodic BCs for the x-direction boundaries, and 0 degree floquet periodic BCs for the...
Back
Top