|
[Sponsors] |
Write heat Flux Expression and Define a Heat Flux boundary Condition in Wall. |
![]() |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
![]() |
![]() |
#1 |
Member
Mey
Join Date: Dec 2019
Posts: 99
Rep Power: 6 ![]() |
Hi Everybody,
I have 2 questions: 1.How should I write exactly an expression to calculate the heat flux on a wall in post? For example: Ave(Heat Flux) @ Location Sum(Heat Flux) @ Location AreaAvg(Heat Flux) @ Location? 2. I have simulated a model, therefore I know the Heat flux through a Wall in my model. When I want use the amount of Heat Flux (W/m2) through the mentioned Wall in the next Simulation, how can I definde for the same wall, the Heat flux amount as a Boundary condition? my Purpose is an optimization and considering a part of my first model to prevent calculating my whole model every time. Best regards |
|
![]() |
![]() |
![]() |
![]() |
#2 | |
Senior Member
Join Date: Jun 2009
Posts: 1,850
Rep Power: 33 ![]() |
Quote:
areaInt(Heat Flux)@Location. Then, if you want to assume uniform heat flux for that total amount in your next model, you do MyNewHeatFlux = areaInt(Heat Flux)@Location / area()@Location The closest of the 3 proposed formulas is the last one, but using the proper syntax areaAve instead of areaAvg areaAve( Variable )@Location = areaInt( Variable )@Location / area()@Location Hope the above helps,
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
||
![]() |
![]() |
![]() |
![]() |
#3 | |
Member
Mey
Join Date: Dec 2019
Posts: 99
Rep Power: 6 ![]() |
Quote:
I appreciate your answer. I have calculated the Heat Flux (W/m2)from the first result in Post through the Expression Areave( Heat Flux) @ Location. The new Problem is my new calculation after the first iteration will be diverged. and I got the Error attached. Wishes |
||
![]() |
![]() |
![]() |
![]() |
#4 |
Senior Member
Join Date: Jun 2009
Posts: 1,850
Rep Power: 33 ![]() |
You got a value for the new simulation, but you did not say how much that value was, and most importantly, its sign.
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
|
![]() |
![]() |
![]() |
![]() |
#5 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,816
Rep Power: 144 ![]() ![]() ![]() ![]() |
This FAQ is the starting point for the convergence problem: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
|
![]() |
![]() |
![]() |
![]() |
#6 | |
Member
Mey
Join Date: Dec 2019
Posts: 99
Rep Power: 6 ![]() |
Quote:
The amount of Heat flux is -22000 (W/m2). It means I lose from the Wall 22000 W/m2. I defined this amount(-22000) in my new simulation as a boundary condition for this wall. I hope I could answer your question. |
||
![]() |
![]() |
![]() |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
How to write a udf to define average temperature at one boundary based on the value o | er_ijaz | Fluent UDF and Scheme Programming | 1 | May 5, 2021 22:43 |
[swak4Foam] How to define boundary condition variables by using previosly defined variables? | pawlo | OpenFOAM Community Contributions | 8 | September 13, 2020 11:37 |
How to define a wall heat flux changing with flow time in udf? Such as: t<0.3, heat f | hitzhwan | Fluent UDF and Scheme Programming | 12 | July 17, 2020 13:28 |
Monitor Heat Flux in CFD-Pre | cltormar | CFX | 5 | November 20, 2014 11:45 |
Define flux type boundary condition for UDS | mvee | Fluent UDF and Scheme Programming | 4 | October 11, 2013 05:06 |