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equivalence ratio calculation on star-cd cell

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Old   April 10, 2012, 05:32
Default equivalence ratio calculation on star-cd cell
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Krishna
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Hello,

Can you please help me in equivalence ratio calculation over computational domain. the fuel is -> C8H18.

my main problem is how to calculate the c8h18 for each cell over domain.

Thanks in advance.

regards,
Krishna
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Old   April 10, 2012, 20:52
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zheng jianjun
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please try this macro, bless.

*set,safr, 15.03442884 !stoichiometry air fuel ratio of iC8H18-kg/kg
operate,getc,conc,1,1 !the mass fraction of fuel vapor

operate,getc,conc,2,2 !the mass fraction of oxygen--
!
operate,smultiply,4.291845494,2,3
!the mass fraction of air in the cell=m_O2/0.233

operate,divide,1,3,5 !F/A =fuel air ratio
operate,smultiply,safr,5,4 !phi=F/A*sto_A/F
spoint 0 0 0
snormal 0 1 0 !
poption,contour !
pltype,section !
angle 0 !
view snormal !
cplot
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Old   April 11, 2012, 01:04
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Krishna
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Thank you very much..

Can you please explain the below points:

1. why u are multiplying oxygen with 4.291845494.


this is how cell data stored
{ CELL DATA
SU "Velocity Component U" m/s
SV "Velocity Component V" m/s
SW "Velocity Component W" m/s
MassFlux "Mass Flux" kg/s
P "Pressure" Pa
PTER "Thermo. Pressure" Pa
TE "Turb Kinetic Energy" m2/s2
ED "Dissipation Rate" m2/s3
VIS "Turbulent Viscosity" Pa s
T "Temperature" K
H "Enthalpy" J/kg
DENS "Density" kg/m3
CP_M "Mean Specific Heat" J/kgK
CP "Specific Heat" J/kgK
COND "Conductivity" W/mK
CONC_001 "C8H18"
CONC_002 "N2"
CONC_003 "O2"
CONC_004 "WFMASS"
CONC_005 "WFTHICK"
CONC_006 "WFTEMP"
CONC_007 "RG"
VOID "Void Fraction"
}

2. please check the above commands once. operate,getc,conc,2,2 !the mass fraction of oxygen-- now i have to run it as a operate,getc,conc,2,3 !the mass fraction of oxygen--

can you please conform this.



Thanks in advance.

Last edited by kri321shna; April 11, 2012 at 02:38.
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Old   April 11, 2012, 03:43
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zheng jianjun
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Q1. why u are multiplying oxygen with 4.291845494.
answer: 4.291845494=1/0.233, multiplying oxygen with this value, you can get the mass fraction of air.


Q2. please check the above commands once. operate,getc,conc,2,2 !the mass fraction of oxygen-- now i have to run it as a operate,getc,conc,2,3 !the mass fraction of oxygen--

Answer: It is all right that you made a small modification as "operatre,getc,conc,2,3",due to the last number stands for "species number", and second to last number represents "register number".
---------------------------------------------------------------------------------------------------------------------------------------------------
operate GETC CONC,IREGS,NSC(1) ==Loads the mass fractions of scalar species NSC into register IREGS.

CONC_001 "C8H18"
CONC_002 "N2"
CONC_003 "O2"
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Last edited by skylent; April 11, 2012 at 04:06.
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Old   April 11, 2012, 05:34
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thank you so much ...
i have checked the operate command like..
operate,getc,conc,2,3

here 2 is the register and 3 is the conc value.


Thank you ...
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