CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Programming & Development

Wrong figure in Hrv. thesis?

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   April 6, 2013, 04:05
Default Wrong figure in Hrv. thesis?
  #1
Senior Member
 
santiagomarquezd's Avatar
 
Santiago Marquez Damian
Join Date: Aug 2009
Location: Santa Fe, Santa Fe, Argentina
Posts: 452
Rep Power: 23
santiagomarquezd will become famous soon enough
Hi there, a few days ago Dr. Axel Larreteguy told me about some concerns about Figure 3.7 in Hrv. thesis (see attachment). Here we have the vectors \vec{\Delta} and \vec{S}, which have units of area and then vector \vec{k}, the correction, which seems to take in account the displacement of \vec{\Delta} from the face centroid b, so that it has units of distance. The concerns are:

1. Why the differences in units?
2. Do the vector decomposition make sense as is drawn?

Below the figure it is stated that vector \vec{k} is not used

3. The correction vector is not used because simplification or because it is zero (I guess so)?

Following the work of Mathur and Murthy

http://www.tandfonline.com/doi/abs/1...915105#preview

it leads to a zero correction. If it is the wrong interpretation

4. How do we interpret the figure?

Thanks in advance,
Attached Images
File Type: jpg NonOrthBound.jpg (25.7 KB, 21 views)
__________________
Santiago MÁRQUEZ DAMIÁN, Ph.D.
Research Scientist
Research Center for Computational Methods (CIMEC) - CONICET/UNL
Tel: 54-342-4511594 Int. 7032
Colectora Ruta Nac. 168 / Paraje El Pozo
(3000) Santa Fe - Argentina.
http://www.cimec.org.ar
santiagomarquezd is offline   Reply With Quote

Old   April 6, 2013, 15:53
Default
  #2
Super Moderator
 
bigphil's Avatar
 
Philip Cardiff
Join Date: Mar 2009
Location: Dublin, Ireland
Posts: 1,086
Rep Power: 34
bigphil will become famous soon enoughbigphil will become famous soon enough
Quote:
Originally Posted by santiagomarquezd View Post
Hi there, a few days ago Dr. Axel Larreteguy told me about some concerns about Figure 3.7 in Hrv. thesis (see attachment). Here we have the vectors \vec{\Delta} and \vec{S}, which have units of area and then vector \vec{k}, the correction, which seems to take in account the displacement of \vec{\Delta} from the face centroid b, so that it has units of distance. The concerns are:

1. Why the differences in units?
2. Do the vector decomposition make sense as is drawn?

Below the figure it is stated that vector \vec{k} is not used

3. The correction vector is not used because simplification or because it is zero (I guess so)?

Following the work of Mathur and Murthy

http://www.tandfonline.com/doi/abs/1...915105#preview

it leads to a zero correction. If it is the wrong interpretation

4. How do we interpret the figure?

Thanks in advance,
Hi,

Not sure if I can answer your questions, but

In Hrv's thesis (and in OpenFOAM), non-orthogonal correction is not employed on the boundary. This assumption is fine if we assume that phi does not vary along the boundary.
Although, if we assume that phi varies linearly along the boundary then non-orthgonal correction is required to maintain accuracy, as outlined in
E. De Villiers thesis (Fig. 4.7).

I believe that this correction is not performed in OpenFOAM because it may lead to mass flux across walls.

But boundary non-orthogonal correction can be employed through use of custom boundary conditions, such as fixedDisplacement (corrected version of fixedValue) in the solidMechanics branch of OpenFOAM-1.6-ext.

Hope it helped,
Philip
bigphil is offline   Reply With Quote

Old   April 7, 2013, 02:37
Default
  #3
Senior Member
 
santiagomarquezd's Avatar
 
Santiago Marquez Damian
Join Date: Aug 2009
Location: Santa Fe, Santa Fe, Argentina
Posts: 452
Rep Power: 23
santiagomarquezd will become famous soon enough
Thanks Philip, it helped! I'm going to elaborate some ideas to post.

Regards.
__________________
Santiago MÁRQUEZ DAMIÁN, Ph.D.
Research Scientist
Research Center for Computational Methods (CIMEC) - CONICET/UNL
Tel: 54-342-4511594 Int. 7032
Colectora Ruta Nac. 168 / Paraje El Pozo
(3000) Santa Fe - Argentina.
http://www.cimec.org.ar
santiagomarquezd is offline   Reply With Quote

Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Urgent! how to plot contours without grid in the figure? ivanbuz FLUENT 11 November 10, 2009 22:44
Abt: Schlieren figure in Tecplot using data jinwon park Tecplot 2 December 27, 2007 07:48
Latex questiuon (figure) John Dongarra Main CFD Forum 5 August 22, 2007 11:06
what's wrong about my code for 2d burgers equation morxio Main CFD Forum 3 April 27, 2007 11:38
How can I post a figure on this forum? ZHU Main CFD Forum 3 June 21, 2000 23:22


All times are GMT -4. The time now is 22:12.