|
[Sponsors] |
December 14, 1999, 01:25 |
mix-derivatives?
|
#1 |
Guest
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? Thanks Mohammad Kermani Fax: 613-520-5715 |
|
December 14, 1999, 01:48 |
Re: mix-derivatives?
|
#2 |
Guest
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.
|
|
|
|
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 01:12 |
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 11:08 |