Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.
radiation heat flux
Posted 2009年11月20日 GMT-5 11:25 3 Replies
Please login with a confirmed email address before reporting spam
Hi
I have a question for radiation heat flux. I am trying to calculate radiation heat
transfer from surface to surface. I made a simple model and set the boundaries
heat flux with surface-to-surface radiation, temperature or insulated. Then I
use "postinterp" function to get radiation flux data. But all numbers are
"NAN". When I go through file->Export->Postprocessing Data, again I see some of
them "NAN". I am guessing it should be `0' not NAN for insulated or temperature
boundaries. I am using following format:
flux = postinterp(fem,'rflux_htgh',[x ;y ;z])
x,y,z vectors are coordinates for nodes.
I always use postinterp function (for convective and conductive simulations) to get my temperature or total heat flux data, but I am having problem with radiation heat flux. How should use this function to get radiation heat flux? Thank you for your suggestions.
Serap
I have a question for radiation heat flux. I am trying to calculate radiation heat
transfer from surface to surface. I made a simple model and set the boundaries
heat flux with surface-to-surface radiation, temperature or insulated. Then I
use "postinterp" function to get radiation flux data. But all numbers are
"NAN". When I go through file->Export->Postprocessing Data, again I see some of
them "NAN". I am guessing it should be `0' not NAN for insulated or temperature
boundaries. I am using following format:
flux = postinterp(fem,'rflux_htgh',[x ;y ;z])
x,y,z vectors are coordinates for nodes.
I always use postinterp function (for convective and conductive simulations) to get my temperature or total heat flux data, but I am having problem with radiation heat flux. How should use this function to get radiation heat flux? Thank you for your suggestions.
Serap
3 Replies Last Post 2009年11月27日 GMT-5 15:37
Please login with a confirmed email address before reporting spam
Posted:
2 decades ago
Hi
I agree NaN is not as I would expected either, If I take the model case HT Tutorail Model Cavity Radiation, there is no NaN in the File Export Postprocessed data, neiter for the subdomains, nor for the boundaries.
Ivar
I agree NaN is not as I would expected either, If I take the model case HT Tutorail Model Cavity Radiation, there is no NaN in the File Export Postprocessed data, neiter for the subdomains, nor for the boundaries.
Ivar
Please login with a confirmed email address before reporting spam
Posted:
2 decades ago
Hi
Thank you so much for your answer. I tried HT Tutorial Model Cavity Radiation and I received some of them “NaN”. I tried in other computer and still I received “NaN”. I am using Comsol3.3a. Do you think this version have some bugs? I attached some pictures also. Thank you for your help and time.
The process I am following is:
1) Run the model
2) File -> Export-> PostProcessing Data
3) Then I select Boundaries from “Export Data From” section
4) From Boundary submenu, I select
a. Predefined quantities : Radiative flux
b. Expression : rflux_htgh
c. Unit : W/m2
Serap
Thank you so much for your answer. I tried HT Tutorial Model Cavity Radiation and I received some of them “NaN”. I tried in other computer and still I received “NaN”. I am using Comsol3.3a. Do you think this version have some bugs? I attached some pictures also. Thank you for your help and time.
The process I am following is:
1) Run the model
2) File -> Export-> PostProcessing Data
3) Then I select Boundaries from “Export Data From” section
4) From Boundary submenu, I select
a. Predefined quantities : Radiative flux
b. Expression : rflux_htgh
c. Unit : W/m2
Serap
Please login with a confirmed email address before reporting spam
Posted:
2 decades ago
Hi
I'm running V3.5a,
I agree I get about 300 times NaN for the radiation flux, but when you check their coordinates you see they are the exteriour boundaries, not those inside the cavity.
Therefore I expect them to be NaN as they are not defined as "radiative", would'nt you too ?
Good luck
Ivar
I'm running V3.5a,
I agree I get about 300 times NaN for the radiation flux, but when you check their coordinates you see they are the exteriour boundaries, not those inside the cavity.
Therefore I expect them to be NaN as they are not defined as "radiative", would'nt you too ?
Good luck
Ivar