How can we merge the different graphs (Two graph) in COM SOL?
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How can we merge the different graphs (Two graph) in COM SOL?
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Text file of "Variable( x , y , Parameter )" instead of "Variable( x , y , z )" when using a 2d model?
Hello,
I want to plot the results of the despersion of the relative Permeability, with respect to two space coordinates x and y (2D Model) and my parametric sweep variable, named "stage".
Actually, I want to save the results, in a .txt file to use them again in a parametric sweep calculation. So the columns should look like:
x y stage rmm.murZZ
0 0 0 1
1 0 0 2
0 0 1 1
1 0 1
Any tips?
I want to plot the results of the despersion of the relative Permeability, with respect to two space coordinates x and y (2D Model) and my parametric sweep variable, named "stage".
Actually, I want to save the results, in a .txt file to use them again in a parametric sweep calculation. So the columns should look like:
x y stage rmm.murZZ
0 0 0 1
1 0 0 2
0 0 1 1
1 0 1
Any tips?
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confusion between comsol 3.5a and 4.3a
hello everyone,
It might be a noob question, but could anyone please tell me how this should work in comsol 4.3a.
So in comsol 3.5a in order to save the normalized electric field i just did this:
created the mesh:
x1=0:1.5e-9:150e-9;
y1=0:1.5e-9:150e-9;
z1=-150e-9:1.5e-9:150e-9;
Then had the export function (comsol_feldexport) as .m file which had the inerpolation done with postinterp.
After that, i saved the field at the grid points by using the following line:
results = comsol_feldexport(fem,filename,x1,y1,z1);
After that I had my fields and i was all happy.
I do not know how i could access fem anymore in comsol 4.3a, as after solving the Mfile, I only get 'ans' in the workspace and fem is not there anymore.
Please let me know if you have any information.
thanks in advance,
It might be a noob question, but could anyone please tell me how this should work in comsol 4.3a.
So in comsol 3.5a in order to save the normalized electric field i just did this:
created the mesh:
x1=0:1.5e-9:150e-9;
y1=0:1.5e-9:150e-9;
z1=-150e-9:1.5e-9:150e-9;
Then had the export function (comsol_feldexport) as .m file which had the inerpolation done with postinterp.
After that, i saved the field at the grid points by using the following line:
results = comsol_feldexport(fem,filename,x1,y1,z1);
After that I had my fields and i was all happy.
I do not know how i could access fem anymore in comsol 4.3a, as after solving the Mfile, I only get 'ans' in the workspace and fem is not there anymore.
Please let me know if you have any information.
thanks in advance,
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Modeling electrical conductivity of CFRP..
Hello everyone,
I am trying to set up electric current model for carbon fiber reinforced polymer in COMSOL to investigate electrical conductivity variation with respect to loading fraction of fibers. Can anybody tell me how i can proceed? which module to be used?
Thanks and regards
I am trying to set up electric current model for carbon fiber reinforced polymer in COMSOL to investigate electrical conductivity variation with respect to loading fraction of fibers. Can anybody tell me how i can proceed? which module to be used?
Thanks and regards
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Enquiry
Dear all,
Please I have these three questions to be answered.
1. Why did the comsol 4.0 did not come with k-omega model which I prefer to k-epsilon model but available in comsol 3.4? Because I believe k-omega is a better model than k-epsilon
2. Is the realizable k-epsilon model the same as using the realizability constraint with k-epsilon model?
3. Then how can one activate the realizability constraint in comsol 4.0?
I will be very happy if all these questions are answered.
Please I have these three questions to be answered.
1. Why did the comsol 4.0 did not come with k-omega model which I prefer to k-epsilon model but available in comsol 3.4? Because I believe k-omega is a better model than k-epsilon
2. Is the realizable k-epsilon model the same as using the realizability constraint with k-epsilon model?
3. Then how can one activate the realizability constraint in comsol 4.0?
I will be very happy if all these questions are answered.
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Geometry present or not depending on a parameter
Hi!
I am trying to create a geometry that will have certain elements appear or disappear depending on a variable. For example: I have a variable "var1" that can take the values of 1 or 2. I have a geometry that hast a plate with a hole in the middle (in 2D, so it would basically look like a rectangle with a circle in the middle). I want to be able to have COMSOL build the geometry with the circle if I input 1 for "var1" and to build the geometry with just the rectangle is I input 2 for "var1"
Thank you very much for your help.
Francesco
I am trying to create a geometry that will have certain elements appear or disappear depending on a variable. For example: I have a variable "var1" that can take the values of 1 or 2. I have a geometry that hast a plate with a hole in the middle (in 2D, so it would basically look like a rectangle with a circle in the middle). I want to be able to have COMSOL build the geometry with the circle if I input 1 for "var1" and to build the geometry with just the rectangle is I input 2 for "var1"
Thank you very much for your help.
Francesco
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Establishing upper and lower limits for a PDE dependent variable
Hi!
I'm solving a PDE system in the physics Coefficient Form PDE and I need to stablish and upper and lower limits for the output values of my dependent variables.
Thank you!
I'm solving a PDE system in the physics Coefficient Form PDE and I need to stablish and upper and lower limits for the output values of my dependent variables.
Thank you!
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Using a step function for a stationary study
I am attempting to model a cyclone using the k-epsilon solver and occasionally get some convergence issues. Would it make sense to use a step function to ramp up the inlet velocity? Can I use a step function with a stationary study?
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Rotate Plane View
Is there a way to select to xz plane view and rotate the view so the z axis is point up? I want to take screen shots to put into a report, but I need my model to be seen as standing up. There should be an easy way to do this, but I have nothing so far. Thanks
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Is it real to simulate Full Lightning Impulse 1,2/50 us in Comsol 4.0?
Hi
I simulate electric fields in high-voltage switchgear.
In my models I use AC/DC Module Electrostatics (es).
If the electrode is under high potential, the boundary condition for that electrode will be Electric Potential with fixed Voltage value.
So, as a result, I get the static electric field distribution.
My aim is to simulate the influence of time dependent voltage namely Full Lightening Impulse 1,2/50 us.
It has form shown on the fig. 1 in following document:
eprints.soton.ac.uk/48555/1/Swaffield_ISH_conference.pdf
The duration of impulse is 50*10e-6 s. As you see it is very short.
So, here is the question.
How can I simulate the model with such time dependent voltage applied to the electrode?
I simulate electric fields in high-voltage switchgear.
In my models I use AC/DC Module Electrostatics (es).
If the electrode is under high potential, the boundary condition for that electrode will be Electric Potential with fixed Voltage value.
So, as a result, I get the static electric field distribution.
My aim is to simulate the influence of time dependent voltage namely Full Lightening Impulse 1,2/50 us.
It has form shown on the fig. 1 in following document:
eprints.soton.ac.uk/48555/1/Swaffield_ISH_conference.pdf
The duration of impulse is 50*10e-6 s. As you see it is very short.
So, here is the question.
How can I simulate the model with such time dependent voltage applied to the electrode?
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Thermofluidic Modelling of hydrogen absorption in metal hydride bed
For learning purposes, I was trying to do the this project Thermofluidynamic Modelling of hydrogen absorption and desorption in a LaNi4.8Al0.2 Hydride Bed at www.comsol.com/papers/7311/download/Lombardo.pdf (published in Comsol conference 2009 Milan). Except instead of two subdomain, I have only one domain containing the porous media and hydrogen enters the cylender through inlet. I am using the Darcy Law's Module and Heat transfer in Porous medium module. For kinetic expression, I have defined the formula in the definition section. I am using the same values and formulas defined in this paper. When I tried to run the program, I get errors which are associated with heat source definition and hydrogen mass absorption rate definition. Furthermore, I would like to see how would you plot the temperature and internal pressure plots which are published in the paper.
I have attached the file. Thank you in advance.
I have attached the file. Thank you in advance.
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COMSOL solver control
Hi,
I am looking at a problem that solves physics at two different time scales. Basically, I want to do the following
At a coarser time scale I want to solve a few partial differential equations (PDEs).
In each coarse time step, the source terms and some coefficients for these PDEs have to be determined by solving a few other PDEs with shorter time steps. The physics at the finer time scale will be solved for a few time steps and then eventually when the fine time scale agrees with the coarser time, the coefficients and source terms are updated. An algorithm will be
For CoarseTimeStep = 1 to n
for FinerTimeStep = 100 smaller time steps in each coarseTimeStep
solve PDE_SET_1 to get coefficients and source terms
end
Use these coefficients and source terms to solve PDE_SET_2
end
Can someone suggest if this is possible to do in comsol? If so, can you kindly point me to appropriate resources.
Thanks,
Hamsa
I am looking at a problem that solves physics at two different time scales. Basically, I want to do the following
At a coarser time scale I want to solve a few partial differential equations (PDEs).
In each coarse time step, the source terms and some coefficients for these PDEs have to be determined by solving a few other PDEs with shorter time steps. The physics at the finer time scale will be solved for a few time steps and then eventually when the fine time scale agrees with the coarser time, the coefficients and source terms are updated. An algorithm will be
For CoarseTimeStep = 1 to n
for FinerTimeStep = 100 smaller time steps in each coarseTimeStep
solve PDE_SET_1 to get coefficients and source terms
end
Use these coefficients and source terms to solve PDE_SET_2
end
Can someone suggest if this is possible to do in comsol? If so, can you kindly point me to appropriate resources.
Thanks,
Hamsa
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how to measure max and min electric field of certain surface area ?
I simulated the insulation with a void , ( rectangular and circle) in 2D.
any way I want measure the max and min of electric field on the surface of the circle (certain surface) then how can I do THIS?
I can measure max and min in whole surface of my geometry but I need measure just at void surface.
thanks in advance
any way I want measure the max and min of electric field on the surface of the circle (certain surface) then how can I do THIS?
I can measure max and min in whole surface of my geometry but I need measure just at void surface.
thanks in advance
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Moving Mesh problem/ Electromagnetism / Induction heating of rod
Dear Ivar,
I am working over a problem, induction heating of a rod moving inside the furnace with a certain velocity, required to relieve stress from the surface.
The furnace is stationary, means the coil while the rod is moving inside the coils. So, I have given the boundary condition accordingly with transitional speed to the rod. However, I am unable to understand, the concept of moving mesh and it feature, the significance of using assembly and pairs feature etc.
All these, I want, to see the result like; the change in thermal profile over the cross section plane at d= 0 ( i.e. From the point it enters into the coil ) while its travel each cm inside the coils till it finally comes out of the coil.
Please send me some reference, example model to understand this further.
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Ishant Jain
I am working over a problem, induction heating of a rod moving inside the furnace with a certain velocity, required to relieve stress from the surface.
The furnace is stationary, means the coil while the rod is moving inside the coils. So, I have given the boundary condition accordingly with transitional speed to the rod. However, I am unable to understand, the concept of moving mesh and it feature, the significance of using assembly and pairs feature etc.
All these, I want, to see the result like; the change in thermal profile over the cross section plane at d= 0 ( i.e. From the point it enters into the coil ) while its travel each cm inside the coils till it finally comes out of the coil.
Please send me some reference, example model to understand this further.
--
Ishant Jain
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Error while processing
Sir,
While computing the results for my model, I got an error which says
" Failed to find consistent initial values.
Segregated group 2
Out of memory during assembly.
Last time step is not converged.
- Feature : Time - Dependent solver 1 (sol1/t1)
- Error : Failed to find consistent initial values. "
Please let me know what would be the error and what are all the probable corrections to be made??
While computing the results for my model, I got an error which says
" Failed to find consistent initial values.
Segregated group 2
Out of memory during assembly.
Last time step is not converged.
- Feature : Time - Dependent solver 1 (sol1/t1)
- Error : Failed to find consistent initial values. "
Please let me know what would be the error and what are all the probable corrections to be made??
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Violating basic transformer equation
Hello all ,
I am doing simulation of two coil system with some gap between the coil , the problem is I defined the No.of turns in Multi turn coil domain and excited with voltage of 220 V , When i am observing current in the secondary coil by short circuiting secondary , its violating the basic equation, that when no.of turns decrease current should be more
N1/N2 = I2/I1 but i am getting the less current in secondary , although my no.of turns in secondary is lo
Can you help me what is the problem
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kishore Naik Mude
I am doing simulation of two coil system with some gap between the coil , the problem is I defined the No.of turns in Multi turn coil domain and excited with voltage of 220 V , When i am observing current in the secondary coil by short circuiting secondary , its violating the basic equation, that when no.of turns decrease current should be more
N1/N2 = I2/I1 but i am getting the less current in secondary , although my no.of turns in secondary is lo
Can you help me what is the problem
--
kishore Naik Mude
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Metal Hydride Storage Simulation
Hello
I am trying to explore the possibility of using COMSOL to simulate the Hydrogen storage in solid metal hydride.
I have seen several papers using COMSOL for this purpose.
I still do not have the software but would like to learn more about it and see if i can get any helping material.
I may use a license copy with other colleges.
Best regards
I am trying to explore the possibility of using COMSOL to simulate the Hydrogen storage in solid metal hydride.
I have seen several papers using COMSOL for this purpose.
I still do not have the software but would like to learn more about it and see if i can get any helping material.
I may use a license copy with other colleges.
Best regards
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Solid mechanics and element settings
Hi!
I am analysing stresses and displacements of simple 2D steel plate with Comsol 4.2. I need to get results calculated by triangle linear plane stress elements for comparison.
How can I change element type to linear? Comsol seems to use quadratic elements by default?
I am analysing stresses and displacements of simple 2D steel plate with Comsol 4.2. I need to get results calculated by triangle linear plane stress elements for comparison.
How can I change element type to linear? Comsol seems to use quadratic elements by default?
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How to calculate the displacement of crack
I need to find the displacement (u) of a crack on a 2D centre crack plate under a load.
I need to find how large the crack has gotten under the load
How can I do this?
I need to find how large the crack has gotten under the load
How can I do this?
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mef in time dependent
Hello to everyone. I have one question regarding the possibility to carry out a Time Dependent Study in mef. There is one good example of Integrated Square-Shaped Spiral Inductor (www.comsol.com/showroom/documentation/model/129/) for Stationary Study in mef. Here from one side of conductor the const value of current is injected and other side is just grounded. I added time-dependent study in the Model and injected time-dependet current with the function depending on t but the solver delivers no results (empty matrix). Where can I be wrong? The time ranges were changed properly, the unit of function has been corrected. Thank you for any help or suggestions.
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