Dear all:

I have a problem. For the so-called Pressure Poisson Equation, we have to do something to 'fix' the solution to some prescribed level. As I known, there are two methods, one is to fix the solution at a point to a constant and the other is to fix the integral of the solution over the domain to a constant. But how to justfy these two methods remains a question to me and, the sencond one seems difficult to implement.

Thanks for your attention.

Zhou

with what type of BCs are of interest?

HI, The second method is better. Since in the first method, the fixed point would 'absorb' most of the numerical error. and in the second method, the numerical error is equally distributed over the computation domain with a lower level which is preferred in most cases.

Hong

Neumann condition. Thank you.

dear,

i am working on the same problem. for you question, take a look at these references:

Briley, W.R.(1974). "Numerical Method for Predicting Three-Dimensional Steady Viscous Flow in Ducts." Journal of Computational Physics, Vol. 14, pp. 8-28.

Roache, P.J.(1976)."Computational Fluid Dynamics." pp.180-185, Hermosa Publishers.