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transient heat flux and temperature analysis
Posted 13 feb 2013, 03:38 GMT-5 3 Replies
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Dear all,
I am very new to COMSOL multiphysics.
I am doing a transient thermal analysis on geometry containing ceramic and aluminum blocks.
for the boundary conditions I need to define volumetric heat generation with respect to time, rest of the other boundary conditions like convection and initial temperature are constant.
As a result of this I want to see temperature and total heat flux for a transient having a microseconds scale.
Please help me....
appreciate all kind of help
Mihir
I am very new to COMSOL multiphysics.
I am doing a transient thermal analysis on geometry containing ceramic and aluminum blocks.
for the boundary conditions I need to define volumetric heat generation with respect to time, rest of the other boundary conditions like convection and initial temperature are constant.
As a result of this I want to see temperature and total heat flux for a transient having a microseconds scale.
Please help me....
appreciate all kind of help
Mihir
3 Replies Last Post 14 feb 2013, 08:57 GMT-5
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Posted:
1 decade ago
Hi
as for any other model, you need to start and proceed the same way: geoemtry, materials, physics, BC's then mesh and solve, and final postprocessing.
Now "bounday" setings are required for typically initial and fixed temperatures and sources, but a "volume source" is a domain condition and not really a "Boundary condition"
Note also that, if you are in any other size than MEMS dimensions (<1mm) then micro-second themperature effects are not really frequent and expected, fromm my knowledge (except perhaps if you are dealing with chemistry and rapid chemical reactions)
--
Good luck
Ivar
as for any other model, you need to start and proceed the same way: geoemtry, materials, physics, BC's then mesh and solve, and final postprocessing.
Now "bounday" setings are required for typically initial and fixed temperatures and sources, but a "volume source" is a domain condition and not really a "Boundary condition"
Note also that, if you are in any other size than MEMS dimensions (<1mm) then micro-second themperature effects are not really frequent and expected, fromm my knowledge (except perhaps if you are dealing with chemistry and rapid chemical reactions)
--
Good luck
Ivar
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Posted:
1 decade ago
Thank you Sir,
for your reply.
The matter is the volumetric heat generation varies with time...for example( the transient is of 0 to 50e-06 seconds)- at 1.26E-06 seconds, it is 4e12 w/m3 and 50e-06 seconds, it is 1e10 w/m3... and for this I want to check total thermal flux and temperature variation as output.
You are requested to direct me for this and if possible sir, please mention the steps..
I am deeply re grated for your inconvenience.
Regards,
Mihir
for your reply.
The matter is the volumetric heat generation varies with time...for example( the transient is of 0 to 50e-06 seconds)- at 1.26E-06 seconds, it is 4e12 w/m3 and 50e-06 seconds, it is 1e10 w/m3... and for this I want to check total thermal flux and temperature variation as output.
You are requested to direct me for this and if possible sir, please mention the steps..
I am deeply re grated for your inconvenience.
Regards,
Mihir
Please login with a confirmed email address before reporting spam
Posted:
1 decade ago
Hi
you need to define your heat shape via an analytical or a combination of step, rectangle or ramp function (Definitions - Functions, then use the correct (t[1/s]) argument when calling your function in the BC or domain variable field, and set up stepping range values such to cover your transitions and it should go.
Last: check your solver "stepping" settings and do NOT use automatic, but try intermediate or strict, check the doc
--
Good luck
Ivar
you need to define your heat shape via an analytical or a combination of step, rectangle or ramp function (Definitions - Functions, then use the correct (t[1/s]) argument when calling your function in the BC or domain variable field, and set up stepping range values such to cover your transitions and it should go.
Last: check your solver "stepping" settings and do NOT use automatic, but try intermediate or strict, check the doc
--
Good luck
Ivar