# standard Vs PRESTO! scheme

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 March 25, 2006, 10:53 standard Vs PRESTO! scheme #1 parag Guest   Posts: n/a Sponsored Links If one uses standard pressure interpolation scheme & for same problem with same all other settings except now PRESTO scheme is employed then converging answers should be same or there will be a huge differnce in answers?

 May 20, 2010, 12:58 Differences Between PRESTO! and Standard Pressure Discretization #2 New Member   Amir Abbas Aliabadi Join Date: May 2010 Posts: 3 Rep Power: 9 To discretize momentum equation, one needs pressure values on the control volume faces. Standard pressure discretization interpolates the pressure on the faces using the cell center values. On the other hand PRESTO! discretization for pressure actually calculates pressure on the face. This is possible using staggered grids where velocity and pressure variables are not "co-located". PRESTO! discretization gives more accurate results since interpolation errors and pressure gradient assumptions on boundaries are avoided. This scheme works better for problems with strong body forces (swirl) and high Rayleigh number flows (natural ventilation). PRESTO! however, is more computationally costly, since you need more memory for "alternate" grids. For example when you solve natural ventilation flows using standard discretization, you assume zero pressure gradient at the wall which gives erroneous velocities at the boundary, but if you use PRESTO! you account for pressure gradient at the boundary and get the correct answer. makaveli_lcf, sina_mech, erdemkucukal and 13 others like this.

 August 23, 2010, 08:09 Reference #3 New Member   A Join Date: Sep 2009 Posts: 14 Rep Power: 9 HI! I am currently studying different pressure schemes for multiphase flows. I try to motivate Fluent recommendation on using PRESTO!. May I ask if you have a reference for what you wrote? Thanks!

 August 23, 2010, 14:16 Reference for PRESTO scheme #4 New Member   Amir Abbas Aliabadi Join Date: May 2010 Posts: 3 Rep Power: 9 Hi, Here is a reference for PRESTO! scheme Peyret, R., 1996. Handbook of Computational Fluid Mechanics. Academic Press Limited, USA. Good Luck

 August 24, 2010, 02:26 Thanks! #5 New Member   A Join Date: Sep 2009 Posts: 14 Rep Power: 9 Hi, Great! Thanks! I tried to find in Tannehill, Versteeg, Pantakar but no luck in those books! BR Andreas

 August 13, 2013, 23:01 #6 New Member   Join Date: Aug 2013 Posts: 5 Rep Power: 6 Hello there, I wondered which section explain the PRESTO method? I was not able to find it in the book? Thank you Baran

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