CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT

Allocating Heat Loss according to positions

Register Blogs Community New Posts Updated Threads Search

Like Tree4Likes
  • 1 Post By AlexanderZ
  • 1 Post By AlexanderZ
  • 1 Post By AlexanderZ
  • 1 Post By AlexanderZ

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 18, 2020, 05:49
Default Allocating Heat Loss according to positions
  #1
Senior Member
 
Sasan Ghomi
Join Date: Sep 2012
Location: Denmark
Posts: 292
Rep Power: 15
sasanghomi is on a distinguished road
Dear friends,

I am trying to simulate conjugate heat transfer. In fact, I have an excel file in which the value of heat loss is written for different positions. That is,

X Y Z HeatLoss[W]

1 0 2 20

2 6 8 50
............

....

...

How Can I import this file into Fluent (as a heat source)?

I appreciate your attention.

Best Regards
Sasan Ghomi
sasanghomi is offline   Reply With Quote

Old   August 19, 2020, 04:22
Default
  #2
Senior Member
 
Alexander
Join Date: Apr 2013
Posts: 2,363
Rep Power: 34
AlexanderZ will become famous soon enoughAlexanderZ will become famous soon enough
1. open your case in fluent
2. initialize the case and write heat flux profile from the surface you are interested it. You will get coordinate of each center of finite surface with respective heat flux value
3. change heat flux values in profile according to your file using interpolation (or any other method)
4. read profile, apply it as boundary condition
sasanghomi likes this.
__________________
best regards


******************************
press LIKE if this message was helpful
AlexanderZ is offline   Reply With Quote

Old   August 19, 2020, 04:56
Default
  #3
Senior Member
 
Sasan Ghomi
Join Date: Sep 2012
Location: Denmark
Posts: 292
Rep Power: 15
sasanghomi is on a distinguished road
Thank you for your response.
However, I want to allocate the heat loss to some regions not just some boundaries.
Do you have any idea for allocating the heat source in a 3D region?

Best Regards
sasanghomi is offline   Reply With Quote

Old   August 19, 2020, 08:41
Default
  #4
Senior Member
 
Alexander
Join Date: Apr 2013
Posts: 2,363
Rep Power: 34
AlexanderZ will become famous soon enoughAlexanderZ will become famous soon enough
it is same approach, choose volumetric heat source
sasanghomi likes this.
__________________
best regards


******************************
press LIKE if this message was helpful
AlexanderZ is offline   Reply With Quote

Old   August 23, 2020, 03:48
Default
  #5
Senior Member
 
Sasan Ghomi
Join Date: Sep 2012
Location: Denmark
Posts: 292
Rep Power: 15
sasanghomi is on a distinguished road
Thank you so much.
I have written something like below;

HTML Code:
3
3
3
1
Volumetric Heat
(-0.0005
-0.005
-0.005
)
(0.07
0.04
0.06
)
(-0.03
0.01
0.07
)
(5000
6000
7000
)
However, I know that the name "Volumetric Heat" should be replaced by a correct name. I have no idea about the right name for the volumetric source of energy. Could you give me a hint, please?

One more question; Is that the procedure through which I can allocate the heat source?

1) Initialization
2) File/Read/Profile

By the way, Are you sure that a profile could be used for specifying volumetric heat source?
When I want to write a profile, it is just applicable for surfaces and boundaries and that is why that I am dubious about using such option for volumetric heat source.


Thank you in advance
Best Regards
sasanghomi is offline   Reply With Quote

Old   August 24, 2020, 01:12
Default
  #6
Senior Member
 
Alexander
Join Date: Apr 2013
Posts: 2,363
Rep Power: 34
AlexanderZ will become famous soon enoughAlexanderZ will become famous soon enough
format is this
Code:
((n point 3)
(x
0.023571428
0.030714285
0.037857141
)
(y
0.0099999998
0.0099999998
0.0099999998
)
(z
0.12
0.12
0.12
)
(total-energy
1611.35
1611.35
1611.35
)
)
instead of name"total-energy" you may use ANY name you prefer
idea is for each point you are defining heat source

of course the best is to define heat source for each center of finite volumes

read profile first, apply it in cell zone conditions as a heat source
initialize
sasanghomi likes this.
__________________
best regards


******************************
press LIKE if this message was helpful
AlexanderZ is offline   Reply With Quote

Old   August 25, 2020, 03:57
Default
  #7
Senior Member
 
Sasan Ghomi
Join Date: Sep 2012
Location: Denmark
Posts: 292
Rep Power: 15
sasanghomi is on a distinguished road
Thank you Alexander.

Just one question;
Are the values of heat sources in the table counted per volume? I mean the values of heat sources in the table will be multiplied by cell volumes and will be allocated to the domain?

So, does it mean that the total heat source would change if I changed the grid size?

I would be thankful if you could clarify it.
__________________
Best regards,
Sasan Ghomi
sasanghomi is offline   Reply With Quote

Old   August 25, 2020, 05:34
Default
  #8
Senior Member
 
Alexander
Join Date: Apr 2013
Posts: 2,363
Rep Power: 34
AlexanderZ will become famous soon enoughAlexanderZ will become famous soon enough
values are in W/[m3]
but the volume here means volume of zone, where profile is applied
so you can change mesh
sasanghomi likes this.
__________________
best regards


******************************
press LIKE if this message was helpful
AlexanderZ is offline   Reply With Quote

Old   September 9, 2020, 10:11
Default
  #9
Senior Member
 
Sasan Ghomi
Join Date: Sep 2012
Location: Denmark
Posts: 292
Rep Power: 15
sasanghomi is on a distinguished road
Dear AlexanderZ

Following our recent discussion, I have another question.
I have a profile in which 3,000,000 points have been used to generate the profile. Something weird is happening. The process of initialization is too time-consuming. it is more than 4 hours that I have been waiting for the initialization.
The simulation includes 12,000,000 grid cells and it is a just conduction heat transfer modeling.
Do you have any ideas about this issue?

I appreciate your attention.
__________________
Best regards,
Sasan Ghomi
sasanghomi is offline   Reply With Quote

Reply


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Continuity Equation for multicomponent simulation lordluan CFX 15 May 19, 2020 19:36
pressure loss in presence of conjugate heat transfer in internal flows nima103 Main CFD Forum 1 September 5, 2019 15:03
convective heat loss in an open cylindrical cavity arriftou FLUENT 0 July 29, 2015 02:00
Error finding variable "THERMX" sunilpatil CFX 8 April 26, 2013 08:00
Writing a UDF for heat loss from a composite wall mali28 Fluent UDF and Scheme Programming 6 January 15, 2012 10:27


All times are GMT -4. The time now is 13:48.