Error when using Boussinesq Model

CFDJ · July 29, 2014, 08:54

Hello everybody,

I am simulating a simple pipe flow with a heated pin in it with forced and natural convection. When I run the Solver with the full buoyancy model (variable density) everything is fine. But when I try to use the boussinesq model (constant density, but a value for the thermal expansivity) i get this error:

Error detected by routine PEEKR
CDANAM = ../../HEATM/TFC/SIGMA/VALUE
CRESLT = NONE

Current Directory : /FLOW/PHYSICS/ZN1/FL1/TURBM/BUOYTURB

+--------------------------------------------------------------------+
| ERROR #001100279 has occurred in subroutine ErrAction. |
| Message: |
| Stopped in routine MEMERR |
| |
| |
| |
| |
| |
+--------------------------------------------------------------------+

I think maybe a value 'Sigma' is missing, but I dont know how I can fix it. Did anyone have a similar Problem or any idea how to fix it?

Thank you, CFDJ

Opaque · July 29, 2014, 15:43

If you are more specific on the details of the turbulence model, perhaps someone here can help you.

For example,

What turbulence model are you using ?
Did you activate the Buoyance Turbulence sub-model ? Which option ?
Did you set the Turbulent Schmidt Number for Buoyancy Turbulence ?
What release of ANSYS CFX are you running ?

For example, the Buoyancy tutorial provided assumes laminar flow. You can change it to turbulence flow, and apply similar settings and see if it works for you.

CFDJ · July 30, 2014, 02:47

Hi,

thank you for your reply. I thought maybe the error code whould be enough, but here are some further informations:

-I'm using the SST Model, however I've already tried others - same error
-I use Production and Dissipation option with a turbulente Schmidt Number of 0.9 and a Dissipation Coefficient of 1. I also tried to run the simulation with no buoyance sub model - still same error
-I'm using CFX 15.0

thank you for your help
CFDJ

ghorrocks · July 30, 2014, 06:08

If you turn buoyancy off entirely (not just the buoyancy turbulence stuff) do you get the error?

CFDJ · July 30, 2014, 07:07

Hi,

when I choose the 'Non Buoyant' option, I don't get the error. My values, wenn I choose the 'Buoyant' option are:

x = 0 m s^-2
y = 0 m s^-2
z = -9.81 m s^-2

Ref. Temp : 572.15K

Ref. Location : Automatic

ghorrocks · July 30, 2014, 07:13

In that case the error is most likely in the way you have set up your materials. What materials are you using?

CFDJ · July 30, 2014, 07:20

Actually I want to work with a liquid metal. But if I run the simulation using the predefined 'Water' Material, I still get the error.

ghorrocks · July 30, 2014, 07:43

The error message is cryptic and I cannot be sure what it is getting at. But I suspect you are missing an essential material property associated with the Buoyancy turbulence model.

CFDJ · July 30, 2014, 07:56

You might be right, but it's confusing that it doesn't work, even if i choose the predefinded Materials like 'Water' or 'Air at 25 C', which also use the Boussinesq Model. I didn't change them. Is it possible that something written in these materials is wrong?

CFDJ · July 30, 2014, 08:00

Sometimes I get additionaly this Error in an extra Window:

No data source for Workspace, cannot monitor Solver data.

ghorrocks · July 30, 2014, 08:09

What do you mean "something written in these materials is wrong?". Something is wrong in your model, that is why you are getting the error. But I can assure you many people have done buoyancy simulations in CFX before (me, for instance) and it worked just fine for us.

I very rarely run CFX inside workbench. It just adds another layer of things to go wrong (as you just found out). So I run CFX in stand alone mode - except in the rare cases when you need workbench to drive parameters or do FSI or something like that.

CFDJ · July 30, 2014, 08:25

I also use stand alone mode. The additional window is just an error-window.

And I know that my model is wrong, but if I use the Libary Material Water and there is still an Error, then the Error can't arise from the Material setup, or am I wrong?

ghorrocks · July 30, 2014, 18:34

Can you post your CCL?

CFDJ · July 31, 2014, 02:47

I think I have found the problem.

CFDJ · July 31, 2014, 02:58

I defined a function for the turbulent Prandtl Number, making it variable. This caused the error, when I tried to use the Boussinesq Model. Now that I know where the error comes from I can try to fix it. Thank you for your support!

thomas. · February 3, 2021, 08:41

Hi @CFDJ, I am facing exactly the same problem (variable turbulent Prandtl number for a mixed convection case). I also noticed that the variable Prandtl number works fine for a non-buoyant case, but not when the buoyancy is activated. Did you manage to make a mixed convection case run, i.e., with buoyancy effects?

July 29, 2014, 08:54	Error when using Boussinesq Model	#1
CFDJ New Member Julian Join Date: May 2014 Posts: 9 Rep Power: 10	Hello everybody, I am simulating a simple pipe flow with a heated pin in it with forced and natural convection. When I run the Solver with the full buoyancy model (variable density) everything is fine. But when I try to use the boussinesq model (constant density, but a value for the thermal expansivity) i get this error: Error detected by routine PEEKR CDANAM = ../../HEATM/TFC/SIGMA/VALUE CRESLT = NONE Current Directory : /FLOW/PHYSICS/ZN1/FL1/TURBM/BUOYTURB +--------------------------------------------------------------------+ \| ERROR #001100279 has occurred in subroutine ErrAction. \| \| Message: \| \| Stopped in routine MEMERR \| \| \| \| \| \| \| \| \| \| \| +--------------------------------------------------------------------+ I think maybe a value 'Sigma' is missing, but I dont know how I can fix it. Did anyone have a similar Problem or any idea how to fix it? Thank you, CFDJ

July 29, 2014, 15:43		#2
Opaque Senior Member Join Date: Jun 2009 Posts: 1,665 Rep Power: 29	If you are more specific on the details of the turbulence model, perhaps someone here can help you. For example, What turbulence model are you using ? Did you activate the Buoyance Turbulence sub-model ? Which option ? Did you set the Turbulent Schmidt Number for Buoyancy Turbulence ? What release of ANSYS CFX are you running ? For example, the Buoyancy tutorial provided assumes laminar flow. You can change it to turbulence flow, and apply similar settings and see if it works for you.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
difference between incompressible k-epsilon model and compressible k-epsilon model	yhy20081016	OpenFOAM Running, Solving & CFD	3	January 19, 2016 07:49
Model assemble - meshing strategy	Aeronautics El. K.	Pointwise & Gridgen	7	August 8, 2015 03:30
K - epsilon VS SST turbulence model	Maicol	Main CFD Forum	0	November 30, 2012 16:25
LES and combustion model	Margherita Cadorin	CFX	0	October 29, 2008 05:24
Boussinesq model reference temperature?	David Agostinho	CFX	2	July 4, 2004 11:55

July 30, 2014, 02:47		#3
CFDJ New Member Julian Join Date: May 2014 Posts: 9 Rep Power: 10	Hi, thank you for your reply. I thought maybe the error code whould be enough, but here are some further informations: -I'm using the SST Model, however I've already tried others - same error -I use Production and Dissipation option with a turbulente Schmidt Number of 0.9 and a Dissipation Coefficient of 1. I also tried to run the simulation with no buoyance sub model - still same error -I'm using CFX 15.0 thank you for your help CFDJ

July 30, 2014, 06:08		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,326 Rep Power: 138	If you turn buoyancy off entirely (not just the buoyancy turbulence stuff) do you get the error?

July 30, 2014, 07:07		#5
CFDJ New Member Julian Join Date: May 2014 Posts: 9 Rep Power: 10	Hi, when I choose the 'Non Buoyant' option, I don't get the error. My values, wenn I choose the 'Buoyant' option are: x = 0 m s^-2 y = 0 m s^-2 z = -9.81 m s^-2 Ref. Temp : 572.15K Ref. Location : Automatic

July 30, 2014, 07:13		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,326 Rep Power: 138	In that case the error is most likely in the way you have set up your materials. What materials are you using?

July 30, 2014, 07:20		#7
CFDJ New Member Julian Join Date: May 2014 Posts: 9 Rep Power: 10	Actually I want to work with a liquid metal. But if I run the simulation using the predefined 'Water' Material, I still get the error.

July 30, 2014, 07:43		#8
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,326 Rep Power: 138	The error message is cryptic and I cannot be sure what it is getting at. But I suspect you are missing an essential material property associated with the Buoyancy turbulence model.

July 30, 2014, 07:56		#9
CFDJ New Member Julian Join Date: May 2014 Posts: 9 Rep Power: 10	You might be right, but it's confusing that it doesn't work, even if i choose the predefinded Materials like 'Water' or 'Air at 25 C', which also use the Boussinesq Model. I didn't change them. Is it possible that something written in these materials is wrong?

July 30, 2014, 08:00		#10
CFDJ New Member Julian Join Date: May 2014 Posts: 9 Rep Power: 10	Sometimes I get additionaly this Error in an extra Window: No data source for Workspace, cannot monitor Solver data.

July 30, 2014, 08:09		#11
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,326 Rep Power: 138	What do you mean "something written in these materials is wrong?". Something is wrong in your model, that is why you are getting the error. But I can assure you many people have done buoyancy simulations in CFX before (me, for instance) and it worked just fine for us. I very rarely run CFX inside workbench. It just adds another layer of things to go wrong (as you just found out). So I run CFX in stand alone mode - except in the rare cases when you need workbench to drive parameters or do FSI or something like that.

July 30, 2014, 08:25		#12
CFDJ New Member Julian Join Date: May 2014 Posts: 9 Rep Power: 10	I also use stand alone mode. The additional window is just an error-window. And I know that my model is wrong, but if I use the Libary Material Water and there is still an Error, then the Error can't arise from the Material setup, or am I wrong?

July 30, 2014, 18:34		#13
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,326 Rep Power: 138	Can you post your CCL?

July 31, 2014, 02:47		#14
CFDJ New Member Julian Join Date: May 2014 Posts: 9 Rep Power: 10	I think I have found the problem.

July 31, 2014, 02:58		#15
CFDJ New Member Julian Join Date: May 2014 Posts: 9 Rep Power: 10	I defined a function for the turbulent Prandtl Number, making it variable. This caused the error, when I tried to use the Boussinesq Model. Now that I know where the error comes from I can try to fix it. Thank you for your support!

February 3, 2021, 08:41		#16
thomas. Member thomas Join Date: Jul 2014 Posts: 50 Rep Power: 10	Hi @CFDJ, I am facing exactly the same problem (variable turbulent Prandtl number for a mixed convection case). I also noticed that the variable Prandtl number works fine for a non-buoyant case, but not when the buoyancy is activated. Did you manage to make a mixed convection case run, i.e., with buoyancy effects?