Laplacian Schemes

msuaeronautics · May 18, 2013, 16:20

Can someone tell me what term this line refers to in the fvSchemes dictionary?

Code:

laplacian((1|A(U)),p)

In other words, what is A(U) and what does this entire term look like/mean on paper? I understand the vertical bar | is a bitwise operator.

msuaeronautics · May 18, 2013, 19:02

I suppose I may have *sort of* solved my own question. Can anyone confirm that this has to do with pressure-velocity coupling- where one would solve Poisson equations for the pressure correction? I consider myself a beginner when it comes to the depths of what's inside the code.

ngj · May 19, 2013, 13:03

Hallo,

Yes, it is the Laplacian used for the solution to the pressure Poisson equation. The

Code:

(1|A(U))

term is the diffusivity of pressure, and it is the inverse of the diagonal elements in the discretised momentum equation, i.e. the diagonal of the left hand side of the matrix system.

Kind regards

Niels

msuaeronautics · May 19, 2013, 22:59

Understood. Thank you.

May 18, 2013, 16:20	Laplacian Schemes	#1
msuaeronautics Member Eric Robertson Join Date: Jul 2012 Posts: 95 Rep Power: 15	Can someone tell me what term this line refers to in the fvSchemes dictionary? Code: laplacian((1\|A(U)),p) In other words, what is A(U) and what does this entire term look like/mean on paper? I understand the vertical bar \| is a bitwise operator. immortality likes this.

May 19, 2013, 13:03		#3
ngj Senior Member Niels Gjoel Jacobsen Join Date: Mar 2009 Location: Copenhagen, Denmark Posts: 1,903 Rep Power: 37	Hallo, Yes, it is the Laplacian used for the solution to the pressure Poisson equation. The Code: (1\|A(U)) term is the diffusivity of pressure, and it is the inverse of the diagonal elements in the discretised momentum equation, i.e. the diagonal of the left hand side of the matrix system. Kind regards Niels msuaeronautics likes this.

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May 18, 2013, 19:02		#2
msuaeronautics Member Eric Robertson Join Date: Jul 2012 Posts: 95 Rep Power: 15	I suppose I may have sort of solved my own question. Can anyone confirm that this has to do with pressure-velocity coupling- where one would solve Poisson equations for the pressure correction? I consider myself a beginner when it comes to the depths of what's inside the code.

May 19, 2013, 22:59		#4
msuaeronautics Member Eric Robertson Join Date: Jul 2012 Posts: 95 Rep Power: 15	Understood. Thank you.