CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum


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

LinkBack Thread Tools Display Modes
Old   December 14, 1999, 02:25
Default mix-derivatives?
Mohammad kermani
Posts: n/a
Hi there:

I need to compute the mix-derivatives in the viscous part of the Navier Stokes. In general a mix derivative looks like:

d( A d(u)/dx )/dy; where A is a general function of x and y.

I wonder if someone can help or introduce a reference?


Mohammad Kermani Fax: 613-520-5715

  Reply With Quote

Old   December 14, 1999, 02:48
Default Re: mix-derivatives?
John C. Chien
Posts: n/a
(1). d(A*(du/dx))/dy = A(x,y)*d(du/dx)/dy + (dA/dy)*(du/dx)= A(x,y)*( (du/dx)at(j+1) - (du/dx)at(j-1) )/(y(j+1)-y(j-1)) + (A(j+1)-A(j-1))/(y(j+1)-y(j-1))*(u(i+1)-u(i-1))/(x(i+1)-x(i-1)), where (du/dx)at(j+1)=(u(i+1,j+1)-u(i-1,j+1))/(x(i+1)-x(i-1)),... (2). CRC math Handbook should have the finite difference formula included. (3). You can also apply the same method directly to the original derivative term.
  Reply With Quote


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
UDM derivatives for - for EHD flow Sandilya Garimella FLUENT 7 September 9, 2013 03:17
Stability Derivatives embolado FLUENT 0 December 27, 2010 02:12
Can we have access temperature derivatives??? behrang2009 Fluent UDF and Scheme Programming 0 July 29, 2010 19:21
Panel Method Doublet Derivatives Gerrit Groot Main CFD Forum 17 September 17, 2007 09:13
Conversion of cell velocity derivatives Manoj FLUENT 0 November 30, 2005 12:08

All times are GMT -4. The time now is 22:16.