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Hobos September 6, 2014 06:19

Drmast Subroutine
 
Dear Colleagues,

I am trying to simulate and compare the mass and heat transfer using drmast and drheat subroutines against the standard mass and heat transfer. I have used some of the equations in the user subroutines provided in star and the methodology and some from YAWS. But so far, I am only able to run the subroutines at droplet temp of 293K but not for temperatures higher than 293K.

Have I done anything wrong?

Please help and I look forward to hearing from you.

Regards,

Hobos

CC GAS CONSTANT (UGC)
UGC=8313
PI=3.1415927
CC MOLECULAR WEIGHT OF AIR OF WHICH N2 WAS ASSUMED
WTMOLN=28.96
CC MOLECULAR WEIGHT OF PENTANE
WTMOL=72
CC - MEAN TEMPERATURE OF FILM (TF)
TF=(T+TD)*0.5
CC================================================ =======================
CC PROPERIES OF AIR
CC================================================ =======================
CC - VISCOSITY AT TEMPERATURE TF (YAWS)
AVA=4.4656
BVA=6.3814E-1
CVA=-2.6596E-4
DVA=5.4113E-8
EQA1=AVA+(BVA*TF)+(CVA*(TF**2))+(DVA*(TF**3))
VISAL=EQA1*1E-3
CC - SPECIFIC HEAT AT CONSTANT PRESSURE AND AT TEMPERATURE TF (YAWS)
ASHA=28.7168
BSHA=7.3458E-3
CSHA=-4.5476E-5
DSHA=1.1641E-7
ESHA=-1.2246E-10
FSHA=5.9045E-14
GSHA=-1.0875E-17
EQA2=ASHA+(BSHA*TF)+(CSHA*(TF**2))+(DSHA*(TF**3))+ (ESHA*(TF**4))
EQA3=EQA2+(FSHA*(TF**5))+(GSHA*(TF**6))
SHAP=EQA3/(WTMOLN*1.0E-3)
CC - THERMAL CONDUCTIVITY (YAWS)
ATCA=-2.2678E-4
BTCA=1.0275E-4
CTCA=-6.0151E-8
DCTA=2.2332E-11
TCA=ATCA+(BTCA*TF)+(CTCA*(TF**2))+(DCTA*(TF**3))
CC================================================ =======================
CC PROPERTIES OF VAPOUR -> PENTANE FUEL
CC================================================ =======================
CC - VISCOSITY (YAWS)
AVV=-3.2016
BVV=0.2675
CVV=-6.6178E-5
EQV1=AVV+(BVV*TF)+(CVV*(TF**2))
VISV=EQV1*1E-3
CC - SPECIFIC HEAT AT CONSTANT PRESSURE AT MEAN TEMPERATURE (YAWS)
ASHV=26.671
BSHV=0.32324
CSHV=4.282E-5
DSHV=-1.664E-7
ESHV=5.6036E-11
EQV2=ASHV+(BSHV*TF)+(CSHV*(TF**2))+(DSHV*(TF**3))+ (ESHV*. (TF**4))
CPVPM=EQV2/(WTMOL*1.0E-3)
CC - THERMAL CONDUCTIVITY (YAWS)
ATCV=-0.00137
BTCV=1.8081E-5
CTCV=1.2136E-8
TCV=ATCV+(BTCV*TF)+(CTCV*(TF**2))
CC================================================ =======================
CC PROPERTIES OF LIQUID -> PENTANE FUEL
CC================================================ =======================
C.....COEFFICENTS OF ALHV,CLHV,NLHV, FOR PENTANE LATENT HEAT (YAWS)
ALHV=39.8543
CLHV=469.65
NLHV=0.398
C.....LATENT HEAT VAPOURIZATION IN kJ/mol
EQ4=(1-(TD/CLHV))**NLHV
LHV=ALHV*EQ4
C.....LATENT HEAT IN J/kg
HV=(LHV*1000)/(WTMOL*1.0E-3)
C....COEFFICENTS OF ASP,BSP,CSP,DSP,FSP, FOR PENTANE SATURATION PRESSURE
ASP=33.324
BSP=-2422.7
CSP=-9.2354
DSP=9.0199E-11
FSP=4.105E-6
C.....SATURATION PRESSURE IN MM Hg (YAWS)
EQ5=ASP+(BSP/TD)+(CSP*LOG10(TD))+(DSP*TD)+(FSP*(TD**2))
SP=10**EQ5
C.....SURAFCE HEAT IN Pa
PS=SP*133.322365
CC================================================ =======================
CC PROPERTIES OF VAPOUR-GAS MIXTURE IN FILM NEXT TO LIQUID SURFACE
CC================================================ =======================
CC - FILM MOLECUAR WEIGHT (WF)
C MOLE FRACTION OF VAPOUR
PF=PS/P
C. MOLE FRACTION OF AIR
OMPF=1-PF
C. MASS FRACTION OF FILM
WF=(OMPF*WG)+(PF*WP)
CC - FILM GAS CONSTANT
VGFGC=UGC/WF
CC - FILM VISCOSITY (VF)
VISF=(OMPF*VISAL)+(PF*VISV)
CC - FILM THERMAL CONDUCTIVITY (TCF)
TCF=(OMPF*TCA)+(PF*TCV)
CC - SPECIFIC HEAT AT CONSTANT PRESSURE (SHFP)
SHFP=((OMPF*WG*SHAP)+(PF*WP*CPVPM))/WF
CC - MASS DIFFUSION COEFFICIENT OF PENTANE LIQUID-GAS MIXTURE (YAWS)
AD=-0.073984
BD=0.000401868
CD=4.34982E-7
DCM=(AD+(BD*TF)+(CD*(TF**2)))*0.0001
CC================================================ =======================
CC CHARACTERISTIC NUMBERS
CC================================================ =======================
CC - RELATIVE VELOCITY
VR=SQRT(((U-UD)**2)+((V-VD)**2)+((W-WD)**2))
CC - REYNOLDS NUMBER
RE=(DEN*VR*DRD)/VISF
SQRE=SQRT(RE)
CC - PRANDTL NUMBER
PR=(SHFP*VISF)/TCF
CC - NUSSELT NUMBER
ANU=2+(0.6*SQRE*(PR**0.3333))
CC - SCHMIDT NUMBER
SCT=VISF/(DEN*DCM)
CC - SHERWOOD NUMBER
SH =2+(0.6*SQRE*(SCT**0.3333))
CC================================================ =======================
CC EVAPORATED MASS
CC================================================ =======================
CC - TRANSFER COEFFICIENT OF MASS
TCM=SH*DCM/(TF*VGFGC*DRD)
CC - PARTIAL PRESSURE OF THE VAPOUR IN THE BULK GAS
PV=(F*P*WG)/WP
CC - EVAPORATED MASS PER SECOND
A=PI*(DRD**2)
EM=(A*TCM*P)*(LOG((P-PV)/(P-PS)))
CC-------------------------------------------------------------------------
RETURN


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