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

4th order discretization of 2nd order difference

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

Reply
 
LinkBack Thread Tools Display Modes
Old   February 11, 2007, 04:01
Default 4th order discretization of 2nd order difference
  #1
dusky.He
Guest
 
Posts: n/a
Does anyone can tell me the form of 4th-order discretization of 2-order difference in cylindrical coordinate.

In Cartesian coordinate, it is (-F(i-2)+16F(i-1)-30F(i)+16F(i+1)-F(i+2))/(12*dx)
  Reply With Quote

Old   February 12, 2007, 01:36
Default Re: 4th order discretization of 2nd order differen
  #2
Harish
Guest
 
Posts: n/a
If you have mathematica/maple/maxima you can find the coefficients using it.Also look for the paper on compact scheme by sanjeev lele ( JCP 1992),it should give you the required finite difference discretization.

  Reply With Quote

Old   February 14, 2007, 05:16
Default Re: 4th order discretization of 2nd order differen
  #3
Chandra
Guest
 
Posts: n/a
discretization is independent of co-ordinate system [d2u/dx2 or d2u/dr2 are same]. If, whatever u have wrote, is correct in Cartesian co-ordinate, it is correct in Cylindrical co-ordinate as well. So, enjoy!! you already have what r u looking for

What changes with change in co-ordinate system is terms itself, not the way it is discretized.

hope it helps.
  Reply With Quote

Old   February 14, 2007, 09:00
Default Re: 4th order discretization of 2nd order differen
  #4
qunwuhe
Guest
 
Posts: n/a
You are right, but I want to discretize the Lapace of Phi in cylindrical coordinate. So the divergence of a gradient in cylindrical is different from the one in Cartetian coordinate.
  Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Limiters for 2nd order solvers Heinz Wilkening Main CFD Forum 1 March 14, 2013 04:40
2nd order and Turbulent-viscosity ratio error freekeer FLUENT 3 October 5, 2010 05:41
2nd order discretization Pavel O FLUENT 0 September 28, 2009 09:15
4th order schemes in channelOodles maka OpenFOAM Bugs 9 January 19, 2009 12:58
High order compact finite difference schemes Mikhail Main CFD Forum 6 August 5, 2003 10:36


All times are GMT -4. The time now is 01:36.