CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   STAR-CD (http://www.cfd-online.com/Forums/star-cd/)
-   -   total pressure in starcd 4.06 007 (http://www.cfd-online.com/Forums/star-cd/62690-total-pressure-starcd-4-06-007-a.html)

whitemelon March 17, 2009 08:42

total pressure in starcd 4.06 007
 
the total pressure in starcd 4.06 007 is wrong, you can check it if you use this version.

cloudbuaa April 2, 2009 01:20

For incompressible flow, the calculation of PTOT is quite correct.
For compressible flow, it's not correct, please try this macro to get real PTOT in v4.06. (Maybe also in some early versions of v4.08)

! Molecular Weight
*SET,WM,28.96
! GAMMA=CP/(CP-(R/WM))
*SET,R,8314.3
*SET,RWM,R / WM * -1.
OPER,GETC,CP,1
OPER,SADD,RWM,1,2
OPER,DIVI,1,2,5
! GAMMA/(GAMMA-1)
OPER,SADD,-1,5,6
OPER,DIVI,5,6,6
! PTOT=PTER,ABSO*(TTOT/T)**(GAMMA/(GAMMA-1))
OPER,GETC,PTER,1,ABSO
OPER,GETC,TTOT,2
OPER,GETC,T,3
OPER,DIVI,2,3,4
OPER,X**Y,4,6,4
OPER,MULT,1,4,4
OPER,SSUB,100000,4,4
OPER,SMULT,-1,4,4


All times are GMT -4. The time now is 03:26.