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Can comsol run in parallel?

Posted 17.09.2010, 13:43 GMT-4 6 Replies

Giorgos Kourakos
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Hi everyone

I need to solve thousand times the same very simple problem (1d advection dispersion equation), using however different distribution velocities each time. I tried to use the Matlab parallel toolbox to split my job but the program crashes when the first comsol command is executed.

Has anyone tried to run comsol in parallel?

Is it possible to run in parallel different problem on the same machine?

Thank you

Giorgos
6 Replies Last Post 21.09.2010, 08:00 GMT-4
Andrew Prudil Nuclear Materials
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Posted: 1 decade ago 17.09.2010, 16:01 GMT-4
It sounds to me like you should be trying to use a parametric sweep. Basically, you can define parameters which are like super variables and can be used as input for geometry and mesh (where normal variables will not be updated).

A parametric sweep allows you to tell COMSOL to run the same file with different input parameters each time. A simple example would be varying the thickness of a geometry from 1cm to 15cm in 1mm steps. I should warn you, that I don't know how the program will respond if changing a parameter results in vastly different geometry (such as two sub domains intersecting where they didn't before).

Parametric sweeps also support distributed memory architecture so you could have each computer on a network calculating a different set of parametric inputs.
It sounds to me like you should be trying to use a parametric sweep. Basically, you can define parameters which are like super variables and can be used as input for geometry and mesh (where normal variables will not be updated). A parametric sweep allows you to tell COMSOL to run the same file with different input parameters each time. A simple example would be varying the thickness of a geometry from 1cm to 15cm in 1mm steps. I should warn you, that I don't know how the program will respond if changing a parameter results in vastly different geometry (such as two sub domains intersecting where they didn't before). Parametric sweeps also support distributed memory architecture so you could have each computer on a network calculating a different set of parametric inputs.
Zeynab Adelpour
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Posted: 1 decade ago 18.09.2010, 03:31 GMT-4
hi my dear

if possible plz help me

i want to sweep the lenght of my structure in parametric sweep, frist, i should define the variable that distiguesh the lenght, but i dont know how define it
or i dont know how define the parametric sweep
hi my dear if possible plz help me i want to sweep the lenght of my structure in parametric sweep, frist, i should define the variable that distiguesh the lenght, but i dont know how define it or i dont know how define the parametric sweep
Danial Tz
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Posted: 1 decade ago 18.09.2010, 03:35 GMT-4

hi my dear

if possible plz help me

i want to sweep the lenght of my structure in parametric sweep, frist, i should define the variable that distiguesh the lenght, but i dont know how define it
or i dont know how define the parametric sweep


You should define your variable in Global Definitions section.
[QUOTE] hi my dear if possible plz help me i want to sweep the lenght of my structure in parametric sweep, frist, i should define the variable that distiguesh the lenght, but i dont know how define it or i dont know how define the parametric sweep [/QUOTE] You should define your variable in Global Definitions section.
Zeynab Adelpour
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Posted: 1 decade ago 18.09.2010, 06:34 GMT-4
hi
thx for answering

if i define the variable in global experssion, it is the correct idea for me.
but how can i allocate a variable to the lenght of steructure
for example i write variable 'a' in the global experssion and define value of it = 2 and then i drew a circular, after that in the radius of it i wrote 'a', then comsol told me ' unknown variable name'
plz help
best regard
hi thx for answering if i define the variable in global experssion, it is the correct idea for me. but how can i allocate a variable to the lenght of steructure for example i write variable 'a' in the global experssion and define value of it = 2 and then i drew a circular, after that in the radius of it i wrote 'a', then comsol told me ' unknown variable name' plz help best regard
Zeynab Adelpour
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Posted: 1 decade ago 18.09.2010, 08:18 GMT-4
and where is the global diffinition section?
and where is the global diffinition section?
Certified Consultant
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Posted: 1 decade ago 21.09.2010, 08:00 GMT-4
Hi, there are two questions in this thread. The first one is regarding cluster computing I assume (since you mention ML parallel toolbox).

To distribute a COMSOL computation in a cluster, you need a floating network license (FNL) of COMSOL to begin with. Please contact your COMSOL sales representative for more information about this license type.

The second question was regarding parametric geometries. Both parametric geometries and cluster computing is explained in this introduction exercise (see p 57-62)
www.comsol.com/shared/downloads/comsol_v4_building_model.pdf

When you are done with the model setup, you can save it as an m-file if you want to continue working with the COMSOL LiveLink for MATLAB.

Note that you do not need MATLAB parallelization through the MATLAB paralell toolbox to distribute the COMSOL computation, unless you also do MATLAB function calls from within the COMSOL model.
--
Kind regards, Niklas Rom, COMSOL

Hi, there are two questions in this thread. The first one is regarding cluster computing I assume (since you mention ML parallel toolbox). To distribute a COMSOL computation in a cluster, you need a floating network license (FNL) of COMSOL to begin with. Please contact your COMSOL sales representative for more information about this license type. The second question was regarding parametric geometries. Both parametric geometries and cluster computing is explained in this introduction exercise (see p 57-62) http://www.comsol.com/shared/downloads/comsol_v4_building_model.pdf When you are done with the model setup, you can save it as an m-file if you want to continue working with the COMSOL LiveLink for MATLAB. Note that you do not need MATLAB parallelization through the MATLAB paralell toolbox to distribute the COMSOL computation, unless you also do MATLAB function calls from within the COMSOL model. -- Kind regards, Niklas Rom, COMSOL

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