# help with rAU variable...icoFoam,

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

 November 18, 2011, 20:42 help with rAU variable...icoFoam, #1 New Member   Ricardo Join Date: Sep 2011 Posts: 15 Rep Power: 14 Dear all, I am trying to understand what the rAU variable does in the code. It is defined in the UEquation and also used to calculate the pEqn (the velocity and pressure of incompressible fluid flow). Can anybody help me understand what this variable means? Thanks it is defined as in the UEqn source code as: rAU = 1.0/UEqn.A()

 November 23, 2011, 02:42 #2 Senior Member   Nima Samkhaniani Join Date: Sep 2009 Location: Tehran, Iran Posts: 1,266 Blog Entries: 1 Rep Power: 24 look at here: http://www.cfd-online.com/Wiki/Veloc...ssure_coupling or a reference cfd book to see how piso or simple Algorithm works but in brief A() returns the diagonal part of matrix of U, so rUA is the inverse of diagonal part Tushar@cfd, kiddmax, apple-tree and 3 others like this.

 November 23, 2011, 03:28 #3 Senior Member   Bernhard Join Date: Sep 2009 Location: Delft Posts: 790 Rep Power: 22 A good reference for these kind of questions in the PhD thesis by Jasak: http://powerlab.fsb.hr/ped/kturbo/Op...jeJasakPhD.pdf apple-tree likes this.

December 8, 2011, 19:25
#4
New Member

Ricardo
Join Date: Sep 2011
Posts: 15
Rep Power: 14
Sorry for late response. But Thank you!!

Quote:
 Originally Posted by nimasam look at here: http://www.cfd-online.com/Wiki/Veloc...ssure_coupling or a reference cfd book to see how piso or simple Algorithm works but in brief A() returns the diagonal part of matrix of U, so rUA is the inverse of diagonal part

December 8, 2011, 19:26
#5
New Member

Ricardo
Join Date: Sep 2011
Posts: 15
Rep Power: 14
Thank you Bernhard!!!

Quote:
 Originally Posted by Bernhard A good reference for these kind of questions in the PhD thesis by Jasak: http://powerlab.fsb.hr/ped/kturbo/Op...jeJasakPhD.pdf

 Tags icofoam, incompressible, peqn, ueqn