Respected sirs, As per the derivation of pressure correction equation in Patankar's SIMPLE algorithm,the density corrections are not directly incorporated. This makes the SIMPLE best suited for the incompressible calculations. Can I use this formulation for compressible subsonic flows directly ? e.g. flame propagation in a premixed fuel air mixture without detonation! Or in other words, where do I have to introduce density corrections, at M > 0.3 or at M >= 1. Thanking you !

In the continuity equation, the mass is

mass = density(new)*velocity(new)*area

= [density(old)+density(correction]*

[velocity(old)+velocity(correction)]*area

~={density(old)*velocity(old)+

density(old)*velocity(correction)+

density(correction)*velocity(old)}*area

velocity(correction)~ p(correction)

density(correction)~ p(correction) through

equation of state That is, you have extra term in pressure correction equation due to density change.

Reference paper: <A collocated finite volume method for predicting flows at all speeds> by I. Demirdzic etc, International J. for Numerical methods in fluids Vol. 16, p1029-1050, 1993

I searched for this article, but could not find it. Peter, can you help me. I would like to expand this formula to the Piso algorithm. This will also be used to enable the modelling of subsonic compressible flow.

Thanks in advance Jean

The title of the paper is:

A Collocated Finite Volume Method for Predicting Flows at all Speeds

by I. Demirdzic, Z. Lilek and M. Peric

If you really can not find it, pass me your Mail address or fax number to Luojia2000@aol.com, I may give you a copy.