gmane.science.analysis.femlab

[COMSOL_Users] PIN junction

foad.david — 2013-05-05T03:40:55

hello 
i'm new in comsol group
i have somme problems in comsol simulation:
1- how to simulate electrical filde in  deplcting region.
2 how to solve quazi neutral region
3-i want to simulate PIN junction and  get the I=f(v) caracteristic.
thank you

[COMSOL_Users] a biphasic waveform

hosn_7 — 2013-04-30T07:41:07

 
 








Dear friends


I want to apply a periodic biphasic square waveform with the following properties:

On time: 400us

Frequency: 30Hz

I can build this waveform bypiecewise function but I do not know how I can apply this waveform to the voltage source in AC/DC and electric current.There is two possibility: by using piecewise function in definition node or by defining a function in material node. Which domain is the correct domain to assess the mentioned waveform(stationary,time-dependent or frequency domain)  


Regards,

[COMSOL_Users] Asymmetric peridic square waveform

Soleyman Davoodi — 2013-04-29T15:17:49

Dear friends





I want to apply a periodic biphasic square waveform with the
following properties:

On time: 400us

Frequency: 30Hz

But as I know the only way to build a biphasic waveform is
by using a Waveform, in this case we have symmetric waveform with duty cycle=
50% , and it is not what I need. On the other hand if I use Rectangle function
to set on and off time, the biphasic property of my desired waveform is lost since
this function make a monophasic waveform.

I would be thankful if someone helps me to solve this
problem.


Faithfully yours,

[COMSOL_Users] I want to simulate a electron's moving trajectory in a electric field.

koleon2001 — 2013-04-09T15:38:03

Dear All:
I'm a new guy using Multiphysics.
My question is , I want to simulate some electrons emission from cathode to anode.
So, I choose both DC/AC model (es) and particle tracing model.
I make a simple test, a square(air), it's lefe line is cathode and right side is anode(7000V). 
Electrons are emissioning form left side, in particle tracing Model ,which parameter should I assign ?
Thanks any way.

[COMSOL_Users] How to plot polarization curve

Bikal — 2013-04-12T22:41:08

I am new to comsol. I don't know how to plot polarization curve. I am using comsol Multiphysics 4.2. I am currently using "Species Transport in the Gas Diffusion layers of a PEM fuel cell', a model given in Comsol library. I will be thankful if anybody helped me in this matter. 

thanks

[COMSOL_Users] AC/DC RMM not converge but there are result

hidayat_akm — 2013-04-04T13:15:45

Hi All,

i have a 3D-PMSM-Modell and after 1 days of simulation (stationary) i got this. it wont converge. Normally ErrEst (estimated error) should smaller than 1e-3 at damping 1 to converge.

Have somebody idea, are this result reliable enough? if i used the result for Heat transfer (HT). What kind of result would be expected?



Stationary Solver 1 in Solver 27 started at DD-Mrz-YYYY 11:36:06.
Nonlinear solver
Number of degrees of freedom solved for: 1739286.
Symmetric matrices found.
Scales for dependent variables:
mod1.A: 1.1e+002
Iter      ErrEst     Damping    Stepsize #Res #Jac #Sol LinIt   LinErr   LinRes
   1      0.0028   0.0100000      0.0029    4    1    5    35     0.11  0.00027
   2       0.003   0.0100000       0.003    6    2    9    53    0.049  0.00012
   3      0.0031   0.0100000      0.0031    8    3   12    69     0.11  0.00027
   4      0.0021   0.0037601      0.0021   10    4   15    87    0.074  0.00018
   5      0.0018   0.0368706       0.002   11    5   17   100    0.072  0.00018

[COMSOL_Users] The simulation of FBAR filters

windzr — 2013-03-25T14:35:01

Hi there
 
I want to simulate FBAR filters in comsol. Could anyone give me some suggestions on how to simulate FBAR filters in comsol£¿Is there any examples about how to simulate FBAR filters in comsol?
 
Thanks for the help
 
Rick

Re: [COMSOL_Users] Used single user license for Comsol 3.5?

2013-03-17T12:26:52

dear professor Braun,

I have an official license for Comsol 3.5 and 3.5a but only the basic
version, so no modules. In principle I am willing to sell. I think that
this can and should be done in an official way and have it somehow
registered with Comsol. However currently I am in Nigeria but I am back in
Holland begin April.
From the 3.5a version I have the code on my laptop in Nigeria. If you are
still interested please do me an offer.

Kind regards,

Gerben Mulder
Boerhaavelaan 185
2334 EJ leiden
Netherlands.

[COMSOL_Users] Used single user license for Comsol 3.5?

Dieter Braun — 2013-03-15T12:15:31

Dear list,

we are interested in Comsol 3.5 as we want to keep our
old 3.1 models/user interface and want to use more
memory/processor capabilities.

Since through Comsol it is not possible to buy old versions,
would it be possible to buy a used single user licence from
one of you users? We have the CDs from a neighboring department.
We are located at a German university (Physics).

Would be great!

Best,
Prof. Dieter Braun.

[COMSOL_Users] 3D coil magnetic field simulation comsol 4.3

backronn1 — 2013-03-15T09:59:04

Hi,

I want to simulate the energy exchange between two coils. But when I choose 3D i can't find the magnetic field physics. I use comsol 4.3. Anyone have a idea how to do this?

[COMSOL_Users] 3D photonic Crystal Fiber

Ahmad Razif — 2013-03-13T04:30:47

Hi, is there anyone here have been design the 3d model for the PCF fiber? can somebody help me coz im getting problem on what to do with their configurations and all.. anyone have the samples for that?

[COMSOL_Users] How the refractive index values varies with respect to doping percentage levels

s_sivab — 2013-03-12T05:34:37

Dear COMSOL_Users,

For the hollow core photonic crystal fiber design in comsol, how to increase the doping level of the gases through refractive index value.Then how the refractive index values varies with respect to doping percentage levels.

i.e., argon refractive index value is 1.00028

to estimate some average properties for a change of the analyte refractive index by 0.1 percent from 1.00028 to 1.10028 calculated for different core doping levels for getting the fundamental mode.

Many thanks, if there is reply.

With regards,
Aruna

[COMSOL_Users] Filling gas refractive index in simulation design with comsol

s_sivab — 2013-03-11T04:49:28

Dear COMSOL_Users,

I need to understand how to fill the gas in the simulation design of hollow core photonic crystal bandgap fiber with comsol i.e., "in subdomain settings by specifying material properties in terms of refractive index, for filling the gas". The refractive index of gas and air are near to 1.000, so how can we vary the refractive index with respect to increase of gas by pressure gradient by simulation with comsol.

It could be very kind of you, if their is reply.

With regards,
Aruna.

[COMSOL_Users] Re: Compile a comsol script into executable file?

wentao2013 — 2013-03-10T22:18:14

Dose this is possible in 4.3 if the license is ok?
Did Mr Li have created an standlone executable file without comsol enviorment?

--- In COMSOL_Users< at >yahoogroups.com, "sealyxi" <sealyxi< at >...> wrote:

Re: [COMSOL_Users] How to Initiate gas refractive index value in core of HC-PCF

marjan zakerin — 2013-03-08T18:39:21

Hi Dear Aruna,

 The hyperelastic seal model in comsol library considers the effect of change in air pressure while pressing a membrane. It is in the solid mechanics library. But you can find some literature formalism which give you the change in dielectric constant as a function of change in the pressure. Such formalisms exists already for fluids.

Regards,
Marjan


________________________________
 From: s_sivab <s_sivab< at >yahoo.com>
To: COMSOL_Users< at >yahoogroups.com 
Sent: Friday, March 8, 2013 2:17 PM
Subject: [COMSOL_Users] How to Initiate gas refractive index value in core of HC-PCF
 

  


Dear COMSOL Users,

By simulation in COMSOL-RF Module-subdomian settings, how to increase the refractive index value of the gas inside the core of Hollow Core Photonic Crystal Fiber(HC-PCF). Because the refractive index value of any gas is nearly (RI = 1). And also how increase the pressure of the gas by simulation.

Many thanks if there is a replay.

With Regards,
Aruna

[COMSOL_Users] When bandwidth widens in the HC-PCF design, do the bandgap of HC-PCF increases

s_sivab — 2013-03-08T13:57:15

Dear COMSOL Users,

The bandwidth widens very fast as d/&#923; is increased. When the bandwidth widens in the design of hollow core photonic crystal fiber, do the bandgap of HC-PCF increases with increase in bandwidh.

Many thanks if there could be a reply.

With regards,
Aruna

[COMSOL_Users] Do the Bandgap is related to spectral bandwidth of the HC-PCF design

s_sivab — 2013-03-08T13:37:44

Dear COMSOL Users,

Do the spectral bandwidth of the HC-PCF in frequency domain is related to  the bandgap, calculated by the band structure of the fiber. When the bandgap is large, do the Spectral bandwidth of the HC-PCF will be increased.

Many thanks if there is a reply.

With regards,
Aruna.

[COMSOL_Users] Do the Bandgap is related to spectral bandwidth of the HC-PCF design

s_sivab — 2013-03-08T13:37:22

Dear COMSOL Users,

Do the spectral bandwidth of the HC-PCF in frequency domain is related to  the bandgap, calculated by the band structure of the fiber. When the bandgap is large, do the Spectral bandwidth of the HC-PCF will be increased.

Many thanks if there is a reply.

With regards,
Aruna.

[COMSOL_Users] How to Initiate gas refractive index value in core of HC-PCF

s_sivab — 2013-03-08T13:17:55



Dear COMSOL Users,

By simulation in COMSOL-RF Module-subdomian settings, how to increase the refractive index value of the gas inside the core of Hollow Core Photonic Crystal Fiber(HC-PCF). Because the refractive index value of any gas is nearly (RI = 1). And also how increase the pressure of the gas by simulation.

Many thanks if there is a replay.

With Regards,
Aruna

[COMSOL_Users] Re: Effective mode area of HC-PCF in COMSOL

cpucampus — 2013-03-05T14:11:44

Hi Aruna,

A hollow-core photonic crystal fiber (HC-PCF) may come in two types:
photonic bandgap PCF (PBG-PCF) and kagome lattice PCF. In the former, the
HC-PCF guides by virtue of its two-dimensional bandgaps, meaning the holey
cladding prevents light from escaping the hollow core. If your fiber is a
PBG-PCF, then it means it will guide light with low losses when the
wavelength of light is located inside one of its bandgaps, hence low losses
and a low effective mode area. When the wavelenght is outside the bandgaps,
the light tends to escape the core, hence higher losses and a high
effective area. I hope this helps.

cheers,

Bora

[COMSOL_Users] Intergrate a SPICE netlist to a Comsol modell

so3ody_2010 — 2013-03-05T12:39:50

Hello memebers :)


I have a LTSPICE Modell which I would like to integrate to a Comsoll Modell.

As an exmaple i read and applied the "I n d u c t o r i n a n A m p l i f i e r C i r c u i t" example under AC DC --> inductive devices and coils and then inductor in circuit... it worked and I could import a .cir List to my modell and simulate it ..

I tryed the same with my Spice and Comsoll Modell but I dosent work ... can any one please tell me why  it dosent work or what shall I do  ??

I work with COMSOL 4.3 and LTSPICE 

this is my .cir list 

v1 4 0 sine(0 327m 44meg) ac 327m
ri 5 4 50
t2 5 0 6 0 td=3.05e-009 z0=50
r5 7 6 16.6666666666667
r3 7 8 16.6666666666667
r4 3 7 16.6666666666667
t1 3 0 tl 0 td=3.05e-009 z0=50
r2 tl 0 100
g:u1:1 0 1 tl 1 13000000
rsh 1 0 68
cc 2 1 330n
r1 2 0 225
c1 2 0 1p
l1 9 8 176n
c2 10 9 70p
c3 11 0 70p
r:u1:3 n001 0 1.
c:u1:3 n001 0 0.00646566956310825
tline 10 11 11 11 td=9.59484978598424e-009 z0=50
.ac lin 10001 10meg 100meg
.SUBCKT tline COMSOL:*
.ENDS
.end


My Comsoll M