CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

curvilinear coordinates

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 31, 2005, 18:47
Default curvilinear coordinates
  #1
Sibel
Guest
 
Posts: n/a
Hi, my thesis statement requires 2D cartesian koordinates turn 2D curvilinear coordinates. So velocity u,v how to change?? Firstly I have get velocity u and v scaler value, but after?? In curvilinear coordinates how to change velocity??
  Reply With Quote

Old   January 31, 2005, 22:01
Default Re: curvilinear coordinates
  #2
Runge_Kutta
Guest
 
Posts: n/a
Welcome to tensor analysis. Brace yourself. There are 3 essential components to vectors and tensors here:

1) Covariant components 2) Contravariant components 3) Physical components

If you use 1) or 2), your velocity components may not have the dimensions of L/T. Ultimately, your final output will need to make dimensional sense. If you are sticking to orthogonal coordinates, you might fare better by simply coding physical components.

Try looking at

http://www.amazon.com/exec/obidos/tg...glance&s=books

or

http://www.amazon.com/exec/obidos/tg...glance&s=books

Also, for a tour de force in this kind of stuff,

http://www.amazon.de/exec/obidos/ASIN/3528080787/qid%3D1107226722/028-8855481-7414120

Shear Flow in Surface-Oriented Coordinates

Ernst-Heinrich Hirschel, Wilhelm Kordulla

ISBN: 3528080787

Format: Paperback, 266pp

Pub. Date: January 1981

Publisher: Ballen Bkslr
  Reply With Quote

Old   February 1, 2005, 02:41
Default Re: curvilinear coordinates
  #3
sibel
Guest
 
Posts: n/a
contravariant or covariant, which can I use contravariant , covariant? is this important for my problem? I cant understant this, so I cannot developed my code? Please explain me this. can you see a numerical examples? I cannot animated on my mind. if I understant this, I will start developed CFD code, but I cannot understant. Please give me some example..I will wait your answer. Every day I am studying until morning, but I am at the same pleace. I cannot develop even one step. please help me. You cannot think how much I want this and how much I need
  Reply With Quote

Old   February 1, 2005, 02:52
Default Re: curvilinear coordinates
  #4
zxaar
Guest
 
Posts: n/a
read the book by peric , that will be better , an dtry to follow the codes he has on his site .. some of them are for curvilinear also .. (but might confuse you since most of them he uses multigrid acceleration ..so u might have to clear multigrids idea too )
  Reply With Quote

Old   February 1, 2005, 03:03
Default Re: curvilinear coordinates
  #5
Runge_Kutta
Guest
 
Posts: n/a
There is no way anyone can just give you a wonderfully simple answer in the context of this forum. Rather than panicking, go to the library and grab several of the books that have been mentioned. Try to figure out what is going on. As you get smarter, come back to this forum and ask specific questions. The book by Warsi is very useful but you may need to get some help from some of your collegues.

My rule of thumb in asking for help is whether I have made a serious attempt to solve the problem myself. Once I have done that, I try to get a helping hand.
  Reply With Quote

Old   February 1, 2005, 03:53
Default Re: curvilinear coordinates
  #6
sibel
Guest
 
Posts: n/a
Yes I understant you, but there is no people to my help. I must do something myself. My problem is very difficult. I get lesson Mr. Z.U.A Warsi from Missisipi State University, when he came to turkey. but he go back Newyork.
  Reply With Quote

Old   February 1, 2005, 04:33
Default Re: curvilinear coordinates
  #7
sibel
Guest
 
Posts: n/a
Mr. Warsi is excellent, but he went. Do yuo know some links about basic code ( include curvilinerar coordinates) Thanks for your suggestions.
  Reply With Quote

Old   February 1, 2005, 22:11
Default Re: curvilinear coordinates
  #8
BradAeroHead
Guest
 
Posts: n/a
Sibel,

My dissertation (on DNS of complex curved channel flows) contains a chapter in which the incompressible 3-D Navier-Stokes equations are expanded into general curvlinear coordinates, using covariant and contravariant components as described above. It includes several examples like a cylindrical channel and a channel with bumps, expressed in these coordinates. I'd be happy to send it to you by email if you like.

My suggestion mirrors those above--you will need to spend some time doing the derivations yourself to get comfortable with this. One key to understanding the concept is the "repeating index" notation, meaning that when you have repeating indices in a product, you must expand the product, like u_i u_i = u_1 u_1 + u_2 u_2 + u_3 u_3, etc.
  Reply With Quote

Old   February 2, 2005, 02:38
Default Re: curvilinear coordinates
  #9
sibel
Guest
 
Posts: n/a
Hi brad thanks your suggestion, you can sent your document to skarabulut@be.itu.edu.tr. My derivative is finished on paper, but I must apply to my source code.

I dont understant repeating indices completly. What do you want to say?
  Reply With Quote

Old   August 21, 2014, 22:47
Default
  #10
New Member
 
Marc
Join Date: Aug 2014
Posts: 1
Rep Power: 0
windwave is on a distinguished road
Hi Brad,
i'd be happy to take a look at your dissertation, if you are willing to email to me as well. I'm trying to write NS equations in orthogonal curvilinear coordinates, above waves.
thanks!
Marc

Quote:
Originally Posted by BradAeroHead
;32646
Sibel,

My dissertation (on DNS of complex curved channel flows) contains a chapter in which the incompressible 3-D Navier-Stokes equations are expanded into general curvlinear coordinates, using covariant and contravariant components as described above. It includes several examples like a cylindrical channel and a channel with bumps, expressed in these coordinates. I'd be happy to send it to you by email if you like.

My suggestion mirrors those above--you will need to spend some time doing the derivations yourself to get comfortable with this. One key to understanding the concept is the "repeating index" notation, meaning that when you have repeating indices in a product, you must expand the product, like u_i u_i = u_1 u_1 + u_2 u_2 + u_3 u_3, etc.
windwave 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
Curvilinear Coordinates - (also for Harish) taw Main CFD Forum 1 November 3, 2008 05:44
Formula for stress in curvilinear coordinates ??? TT Main CFD Forum 2 January 26, 2006 11:43
Roe States (average) in curvilinear coordinates? Bernard Parent Main CFD Forum 3 February 29, 2000 11:02
ENO-schemes in curvilinear coordinates Mathias Main CFD Forum 0 January 4, 1999 06:12
Orthogonal curvilinear coordinates Rudolf Pfeiffer Main CFD Forum 6 December 10, 1998 10:20


All times are GMT -4. The time now is 05:38.