|
[Sponsors] |
August 23, 2022, 02:27 |
Radiation heat transfer
|
#1 |
Member
Meysam
Join Date: Dec 2019
Posts: 81
Rep Power: 6 |
Hi everybody,
I would like to calculate the radiation heat transfer in Post. Normally, through areaInt(heat Flux)@ Location, I am able to calculate total heat Flux. I would like to know how it is possible to calculate the radiation portion for example in a domain or interface etc. Is it possible at all? I have found the quantities ''Wall Irradiation Flux" and "Wall Absorbed Radiation Flux'' which I don't know whether they are trustable values and what do they calculate exactly in post??!! wishes, |
|
August 23, 2022, 11:34 |
|
#2 |
Senior Member
Join Date: Jun 2009
Posts: 1,806
Rep Power: 32 |
Your question is incomplete, which may explain your confusion with the different variables. For starters: CFD-Post does not compute any of them, only post-process the results from the Ansys CFX Solver.
Heat Flux = Convective Heat Flux + Radiation Heat Flux Radiation Heat Flux = Incoming Radiative Heat Flux - Outgoing Radiative Heat Flux Incoming Radiative Heat Flux = Integral over the hemisphere of radiation coming from anywhere projected over the surface --> Irradiation Flux Outgoing Radiative Heat Flux = Emitted Radiative Heat Flux + Reflected Radiative Heat Flux I will leave it at this point since I think you should be able to complete the rest from here.
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
|
August 23, 2022, 19:07 |
|
#3 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,706
Rep Power: 143 |
I will add that I recommend you do a small benchmark case, with two surfaces of known temperature so the heat transfer is a simple analytical equation. Model this and make sure you can get the correct radiative heat transfer. And then in the post processing you can see what all the radiation heat transfer variables represent.
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
|
August 24, 2022, 07:14 |
|
#4 | |
Member
Meysam
Join Date: Dec 2019
Posts: 81
Rep Power: 6 |
Quote:
It seems a good idea. Thanks a lot. |
||
August 24, 2022, 07:18 |
|
#5 | |
Member
Meysam
Join Date: Dec 2019
Posts: 81
Rep Power: 6 |
Quote:
My meaning was in the Post Processing. Perhaps I called it wrongly. Let me explain more. I have a model which I simulated. My aim was first, to evaluate the heat flux in the system. As I said , through the mentioned expression, it is possible to calculate the heat flux. My next goal is calculating the portion of radiation in the total Heat Flux. Your explanation was exact, which I could guess. But I would like to know if the quantities such as ''Wall Irradiation Flux" and "Wall Absorbed Radiation Flux'' are suitable or I shoud find other way to calculate the radiation portion? Specially when they call with Wall ... . As I know and see in my results there is a different between the value of Wall Heat Flux and Heat Flux. regards, |
||
August 24, 2022, 09:31 |
|
#6 | |
Senior Member
Join Date: Jun 2009
Posts: 1,806
Rep Power: 32 |
Quote:
If i recall correctly, Heat Flux is the sum of convective and radiation heat flux as well. So, it is perfectly OK to subtract areaInt(Wall Convective Heat Flux)@Boundary from areaInt(Heat Flux)@Boundary to obtain the Radiative Heat Flow on the boundary. The other radiation quantities are useful if you want to understand the radiation splits: emission, absorption, etc..
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
||
August 24, 2022, 09:38 |
|
#7 | |
Member
Meysam
Join Date: Dec 2019
Posts: 81
Rep Power: 6 |
Quote:
I appreciate your clear answer. I wish you the bests. regards, |
||
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
chtMultiRegionSimpleFoam: Thermal Conduction + Surface-To-Surface Radiation | Zeppo | OpenFOAM Running, Solving & CFD | 16 | May 18, 2017 18:04 |
Interphase mass transfer of a reaction | cfx_ws1992 | Main CFD Forum | 0 | May 15, 2017 21:42 |
Difficulty In Setting Boundary Conditions | Moinul Haque | CFX | 4 | November 25, 2014 17:30 |
Conjugate heat transfer and radiation modeling questions | shankara.2 | FLUENT | 0 | April 21, 2009 15:55 |
Radiation Heat Transfer | The IFRF Heat Transfer Team | Main CFD Forum | 0 | January 31, 2000 14:02 |