|
[Sponsors] |
make constant parameter, used by a boundary condition, variable? |
![]() |
|
LinkBack | Thread Tools | Search this Thread | Display Modes |
![]() |
![]() |
#1 |
New Member
Katsantonis Michalis
Join Date: Dec 2017
Posts: 21
Rep Power: 8 ![]() |
Greetings,
as the title says. Specifically in my case, ideally I would want to change the value of Ta (ambient temperature) in the externalWallHeatFluxTemperature bc, which will take values from a .data timeline file. Is that plausible? If not, is there a way? example: Code:
potWalls { type externalWallHeatFluxTemperature; mode coefficient; Ta constant 300.0; h constant 5.0; thicknessLayers (0.02 0.3 0.02); kappaLayers (54.0 0.04 54.0); kappaMethod fluidThermo; value $internalField; } |
|
![]() |
![]() |
![]() |
![]() |
#2 |
New Member
Katsantonis Michalis
Join Date: Dec 2017
Posts: 21
Rep Power: 8 ![]() |
I considered using the timeVaryingUniformFixedValue bc, but I think it's not the one, as I want to simulate the heat loss through a composite wall, where the fluid temperature outside should be changing.
|
|
![]() |
![]() |
![]() |
![]() |
#3 |
Senior Member
Yann
Join Date: Apr 2012
Location: France
Posts: 1,169
Rep Power: 27 ![]() |
Hi Mixkats,
In the externalWallHeatFluxTemperature header, we can read this : Code:
The ambient temperature Ta is specified as a Foam::Function1 of time but uniform is space. Code:
Ta table ( (0 293) (1 303) (2 313) ); Cheers, Yann |
|
![]() |
![]() |
![]() |
![]() |
#4 |
New Member
Katsantonis Michalis
Join Date: Dec 2017
Posts: 21
Rep Power: 8 ![]() |
Hey Yann, thank you for your fast and enlightening reply.
It work, and I also made it read from the file "Tw.data". Let me mention that this feature of the externalWallHeatFluxTemperature, wasn't available at OF.3.1 or OF.4 , so I had to change to OF.8. Thanks again Yann! Code:
potWalls { type externalWallHeatFluxTemperature; mode coefficient; Ta tableFile; TaCoeffs { file "Tw.data"; // name of data file outOfBounds clamp; // optional out-of-bounds handling interpolationScheme linear; // optional interpolation method } h uniform 5.0; thicknessLayers (0.02);//metal sheet of the cooking vessel kappaLayers (14.3);//cooking vessel therm. cond. kappaMethod fluidThermo; value $internalField; } |
|
![]() |
![]() |
![]() |
![]() |
#5 |
Senior Member
Yann
Join Date: Apr 2012
Location: France
Posts: 1,169
Rep Power: 27 ![]() |
Thanks for your feedback mixkats. I am glad to know you have been able to sort it out and I hope it will be helpful to other users!
Yann |
|
![]() |
![]() |
![]() |
![]() |
#6 |
New Member
Katsantonis Michalis
Join Date: Dec 2017
Posts: 21
Rep Power: 8 ![]() |
Finally, I run the simulation, but unfortunately with the new OF version the velocity fields do not obey some fundamentals of the fluid in the mesh. In the mesh there is air fluidizing sand, which should fluidize in the minimum velocity of 0.18 m/s, from experimental data. Now it can fluidize vigorously even at 0.1 m/s, which is not very true. And unfortunately I'm not in the position to determine the perfect schemes and all that.
Is there maybe a way to insert the table with groovyBc for the specific value of Ta? |
|
![]() |
![]() |
![]() |
![]() |
#7 |
New Member
Katsantonis Michalis
Join Date: Dec 2017
Posts: 21
Rep Power: 8 ![]() |
Hello,
so I managed to get the BC running smoothly. But finally it does not follow reality very much, at least as I would want it to. The heat flux is appearing the opposite direction from that I want. The fileTable for Ta gives values to Ta slightly lower than from the fluid in the mesh in each time step, so shouldn't the heat flux flow from the inside to the outside? Is there a way to resolve this? Code:
potWalls { type externalWallHeatFluxTemperature; mode coefficient; Ta tableFile; TaCoeffs { file "Tw.data"; // name of data file outOfBounds clamp; // optional out-of-bounds handling interpolationScheme linear; // optional interpolation method } h uniform 2500; thicknessLayers (0.005); kappaLayers (14.3); kappaMethod fluidThermo; value $internalField; } Is it maybe the type of value I'm using ($internalField)? |
|
![]() |
![]() |
![]() |
Tags |
boundary condition, constant, externalwallheatfluxtemp |
|
|
![]() |
||||
Thread | Thread Starter | Forum | Replies | Last Post |
Radiation in semi-transparent media with surface-to-surface model? | mpeppels | CFX | 11 | August 22, 2019 07:30 |
Wrong flow in ratating domain problem | Sanyo | CFX | 17 | August 15, 2015 06:20 |
Error finding variable "THERMX" | sunilpatil | CFX | 8 | April 26, 2013 07:00 |
emag beta feature: charge density | charlotte | CFX | 4 | March 22, 2011 09:14 |
compile errors of boundary condition "expDirectionMixed" | liying02ts | OpenFOAM Bugs | 2 | February 1, 2010 20:11 |