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Linfeng BI November 19, 2002 11:23

Solve Poisson equation
HI,all I am trying to implement a Poisson solver(firstly 2D) using FFT. All boundaries are von Neumann. I employ a cosine FFT along x direction and then solve tridiagnal systems along y for each wave number K. But you know the matrix for K=0 is singular. While some articles say that it can be decided by the properties of the physical problem,but I do not know what the tricks are. Any comments are greatly appreciated! Linfeng

Ben Houston November 19, 2002 13:54

Re: Solve Poisson equation
Try Jos Stam's paper on the topic: Jos Stam, "A Simple Fluid Solver based on the FFT", Journal of Graphics Tools Volume 6, Number 2, 2001, 43-52

Avaiable here:

Cheers... -ben houston

Linfeng BI November 20, 2002 10:09

Re: Solve Poisson equation
The paper is interesting,but it says little about the FFT boundary treatment.Thank you,anyway.


Ben Houston November 20, 2002 13:28

Re: Solve Poisson equation
Well, there is some discussion as well in Numerical Recipes about FFT and boundary conditions. But its been a while since I've looked at it.

Linfeng BI November 21, 2002 00:46

Re: Solve Poisson equation
Yeah!thanks,Ben.I read through the chapters there and got a much more clearer concept about it. And then, I made it!


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