Quantcast
Channel: Latest Discussions - COMSOL Forums
Browsing all 26527 articles
Browse latest View live

Using 'if' statement with two conditions

Hi, I want to use and if statement in COMSOL but I need it to have two conditions. I want to calculate the value of the x coordinate when y = 0 and T=300. Something like: if(y ==0 and T == 300, xi ==...

View Article


Boundary electromagnetic heat source and convective cooling

Hi, I am modelling amicroelectrode array with joule heating module. The structure consists of a glass substrate block, an electrode array (spiral or parallel) on top of the substrate, and a fluid...

View Article


Trouble coupling heat transfer physics for both fluids and solids

Hey all, So I'm getting stuck with my model where I try to couple three different physics. The three physics are: Electric Currents, Heat transfer in Solids, and Heat transfer in Fluids. Basically what...

View Article

Split complex variable in real and imaginary parts and iterative solver...

Hi, i'm tring to simulate an indutcor that produce some joule heating on a thin slab. This slab is a non linear material and has a HB curve. I work with 30kHz and i'm using a frequency solver with an...

View Article

2D interpolation of material properties as function of Temperature and Pressure?

Hi, I see that COMSOL 4.2a allows 2D interpolations, how would that be used to interpolate fluid properties, such as density, conductivity, cp, etc, as functions of temperature and pressure of the...

View Article


Creating randomly placed beads/particles in COMSOL?

Hi, I am trying to model a uFluidic capacitor system for electrical impedance spectrometry. It would be ideal if I could create a variable (> 1000) particles with certain properties (permittivity ,...

View Article

about AC signal calculations in Comsol

Hi all, I am curious about AC signals in Comsol. Why do we need to add an analytic function from the functions subtitle to work with an AC signal? I added a waveform of square wave. If I do not place...

View Article

Problem when importing CAD file into COMSOL

Hello Using COMSOL, I have imported a geometry (step file “.stp”) into COMSOL and converted it into COMSOL object. Afterwards, the following error message keeps popping up: “Unsupported degree on...

View Article


limitations of number of data in table or result.

Hi, I am using the transient solver in RF modual, and recording the time-varying electric field. For example, I have the following setteings: Comsol is set to record the electric field at a given point...

View Article


Electric Field norm evaluations

Greetings, Is there a way to get the value of the electric field norm by putting in exact coordinates and getting an evaluation? I am trying to get the E-Field norm value right above the surface of my...

View Article

How to find Current and electric field ??

Hello sir, I am student. and learning this Comsol 4.2 software..so i need a help.. My problem statement is like, one meter length semiconductor wire (Ge) and radius is 0.3mm. if i am applying 25V DC...

View Article

Thermal stress option seems to be missing

I'm looking to model stress and deformation in parts with differing thermal expansion coefficients as a result of a temperature change. Thermal stress is supposed to be available in the solid mechanics...

View Article

Tension Force

The material I am investigating has much lower tension limit than compression. So I want to use COMSOL to simulate the tension in the material, excluding the interference from compression. In the...

View Article


Convergence problems in time dependent simulations

Hello, does anyone has experience how to solve convergence problem in time dependent simulations ? I tried to produce square wave input waveform from a sine wave input and using two diodes to cut the...

View Article

error of tolerances

Hi, I am working on an AC model. The frequency of my signal is 1.3e10 Hz. I am specifying the time interval as (0, 0.1*T, 5*T) and I get an error: "Failed to find time step so that given tolerances are...

View Article


export image file in java from COMSOL and also plotting while solving

I am running a bunch of 1 hour time dependent COMSOL models in a big 'for' loop. I can get Eclipse to export a .txt file for each iteration of the 'for' loop and I can show a progress bar and a 2D/3D...

View Article

PML with structural mechanics

I am trying to use a PML with my model. The model uses solids and shells in the structural mechanics. The PML is around a solid block on five sides. However when I attempt to solve I get the error...

View Article


Questions about Load Case

Hi, I am new to Solid Mechanics interface. I have a question about the load case. What does load case mean? Also what are lgGravity, lgForce, cgGravity, and cgForce? I am reading this:"Use Load Group...

View Article

Cantilever beam fracture

Hi Everybody I have a question regarding analysis of deflection of the cantilever beam. As it is clear, If I apply a small force on tip of the cantilever it will deflect. However in simulation I don't...

View Article

Weak boundary condtitions in magnetic field calculations

Hey, I have an easy but large model, which can be made smaller by identifying a unit cell. In this unit cell I want to implement periodic boundary conditions for the magnetic field (B) . The only...

View Article
Browsing all 26527 articles
Browse latest View live