
[Sponsors] 
November 24, 2011, 10:41 
I have a problem about possion pressure equation

#1 
New Member
kanzaki urumi
Join Date: Nov 2011
Posts: 2
Rep Power: 0 
hello everyone.
I have a problem about my research. my prof. give me a problem to me that i need to resolve this week. my research is about PIV,now i have velocity in x,y axis(u and v) but i know don't how to calculate pressure from velocity i go find in google but i don't understand much, how to use possion pressure equation. i need to know how to use velocity to calculate pressure because i have to write C++ program to calculate its for me and compare to openfoam in next step. anyone have any idea about it pls help me and thank you very much guy. ps. i'm sorry if my english is not correct clz i'm not a native eng speaker. 

November 24, 2011, 14:18 

#2  
Senior Member
Arjun
Join Date: Mar 2009
Location: Nurenberg, Germany
Posts: 702
Rep Power: 19 
Quote:
you have to derive continuity equation from velocity, which would be like poisson equation. Solve this by any matrix solver. 

November 25, 2011, 09:21 

#3 
New Member
Carlos
Join Date: Nov 2011
Location: The Netherlands
Posts: 17
Rep Power: 7 
You indeed need the continuity equation. However that will not be sufficient as only rho and V are the only quantities embedded into the continuity equation. How to proceed largely depends on the type of flow you have. Could you give us some more specifics about the type of flow?
If the flow is for example incompressible, you will need both the continuity and the momentum equation (in x and y direction). The momentum equation is a vector equation and gives you two equations in 2D. Along with the continuity equation you have then three equations in total. The unknowns are then u, v and p. Thus the system is solvable.
__________________
"Do not worry about your difficulties in Mathematics. I can assure you mine are still greater."  Albert Einstein 

November 25, 2011, 19:41 

#4  
Senior Member
Arjun
Join Date: Mar 2009
Location: Nurenberg, Germany
Posts: 702
Rep Power: 19 
Quote:


November 26, 2011, 11:25 

#5 
New Member
kanzaki urumi
Join Date: Nov 2011
Posts: 2
Rep Power: 0 
thank you every one
now i know how to solve it thank you for advice 

Thread Tools  
Display Modes  


Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Strcture of pressure correction equation in PISO stable over time ?  sebi  Main CFD Forum  1  October 26, 2010 22:19 
Physical meaning of pressure in pressure eqn  dontknow  Main CFD Forum  2  August 30, 2010 10:12 
A fundamental problem about Pressure equation of the potentialFoam solver  dbxmcf  OpenFOAM Running, Solving & CFD  0  October 6, 2006 11:32 
pressure poisson equation on staggerred grid  chandra  Main CFD Forum  9  May 5, 2005 06:01 
Gas pressure question  Dan Moskal  Main CFD Forum  0  October 24, 2002 22:02 