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-   -   correction of KIVA Itape (http://www.cfd-online.com/Forums/main/11334-correction-kiva-itape.html)

hama May 2, 2006 03:41

correction of KIVA Itape
 
HELLO:

I'am a new KIVA user I have KIVA 2, and ITAPE also,I want to improve this my ITAPE.

I already made a simple simulation of an internal combustion engine which functions to the natural gas (i.e. I assume that this fuel is100% of methane CH4).

I use the KIVA-II code to calculate the outputs to this simulation and I animate it with TECPLOT software.

According to the (fig 1,2 and3) I note that the flame didn't propagate from the spark plug toward the walls of the cylinder; therefore, the methane/air mixture didn't burn , where I didn't observe any absence of methane and the oxygen after the simulation.

My question is why the spark plug didn't produce a flame that it should be propagates itself on the whole mixture that exists in the combustion chamber.

Or my question with another way is - how I can I get a good propagation of the flame through a methane/air mixture in the combustion chamber-.

If anyone can send me ITAPE or OUTPUT, that'll be very helpful to me.

If anyone want detailles just send and I will do.

thanks

Engine specifications:

Bore 10.47 cm

Stroke =9.53 cm

Clearance=1.26 cm

Compression ratio=8.56

Chamber shape is a disk

RPM =2000 rpm

Fuel : methane (100% CH4)

Equivalent ratio 0.8969

Sparking location : central

ITAPE file:

t3aaa k053190 20x1x22 2-d baseline, w/qsou,chem3190

irest 0

ipost 1

nx 45

ny 1

nz 30

lwall 1

nchop 5

lpr 0

jsectr 1

irez 2

ncfilm 99999

nctap8 99999

nclast 99999

cafilm 45.

cafin 91.0

cadump 9.99e+9

dcadmp 9.99e+9

angmom 1.0

cyl 1.0

dy 0.0

pgssw 0.0

sampl 0.0

dti 1.0e-6

dtmxca 9.99e+9

dtmax 5.0e-5

tlimd 0.0

twfilm 9.99e+9

twfin 9.99e+9

fchsp 0.25

stroke 9.53

squish 1.26

rpm 2000.0

atdc -181.0

conrod 16.34

offset 0.0

swirl 0.0

swipro 0.00

thsect 0.5

epsy 1.0e-2

epsv 1.0e-3

epsp 1.0e-4

epst 1.0e-3

epsk 1.0e-3

epse 1.0e-3

gx 0.0

gy 0.0

gz 0.0

tcylwl 653.0

thead 653.0

tpistn 653.0

tvalve 653.0

tempi 350.0

pardon 0.0

a0 0.0

b0 1.0

anc4 0.05

adia 0.0

anu0 0.0

visrat-.66666667

tcut 700.0

tcute 1200.0

epschm 0.02

omgchm 1.0

tkei 0.3

tkesw 1.0

sgsl 0.0

uniscal 0.0

airmu1 1.457e-5

airmu2 110.0

airla1 252.0

airla2 200.0

expdif 0.2

prl 0.74

rpr 1.11

rprq 1.0

rpre 0.769231

rsc 1.11

xignit 6.0e+3

t1ign -1.425e-2

tdign 1.5e-2

ca1ign-10.0e+0

cadign 10.0

iignl1 1

iignr1 6

jignf1 1

jignd1 1

kignb1 2

kignt1 4

iignl2 0

iignr2 0

jignf2 0

jignd2 0

kignb2 0

kignt2 0

kwikeq 1

modmh 1

amh 10.0

bmh 0.5

cebu 1.

numnoz 0

numvel 0

injdist 0

kolide 0

t1inj 2.5e-2

tdinj 1.40e-3

ca1inj 95.0

cadinj 12.672

tspmas 0.0000

pulse 2.0

tnparc 0.00

rhop 0.0000

tpi 300.0

turb 1.0

breakup 0.0

evapp 0.0

npo 46

nunif 10

1 1 0.000 0.0

2 1 0.116 0.0

3 1 0.233 0.0

4 1 0.349 0.0

5 1 0.465 0.0

6 1 0.582 0.0

7 1 0.698 0.0

8 1 0.814 0.0

9 1 0.931 0.0

10 1 1.047 0.0

11 1 1.163 0.0

12 1 1.280 0.0

13 1 1.396 0.0

14 1 1.512 0.0

15 1 1.629 0.0

16 1 1.745 0.0

17 1 1.861 0.0

18 1 1.978 0.0

19 1 2.094 0.0

20 1 2.210 0.0

21 1 2.327 0.0

22 1 2.443 0.0

23 1 2.559 0.0

24 1 2.676 0.0

25 1 2.792 0.0

26 1 2.908 0.0

27 1 3.025 0.0

28 1 3.141 0.0

29 1 3.257 0.0

30 1 3.374 0.0

31 1 3.490 0.0

32 1 3.606 0.0

33 1 3.723 0.0

34 1 3.839 0.0

35 1 3.955 0.0

36 1 4.072 0.0

37 1 4.188 0.0

38 1 4.304 0.0

39 1 4.421 0.0

40 1 4.537 0.0

41 1 4.653 0.0

42 1 4.770 0.0

43 1 4.886 0.0

44 1 5.002 0.0

45 1 5.119 0.0

46 1 5.235 0.0

nho 0

square 0.0

rcornr 0.0

nstrt 0

icont 11101111011110000000011000

mirror 0

nvzone 0

nvvvec 0

nvpvec 0

nvcont 0

nsp 5

ch4 rho1 4.9653E-5

o2 rho2 1.9861E-4 mw2 32.000 htf2 0.0

n2 rho3 6.5344E-4 mw3 28.016 htf3 0.0

co2 rho4 0.0 mw4 44.011 htf4 -93.965

h2o rho5 0.0 mw5 18.016 htf5 -57.103

rtout 0.0

topout 0.0

botin 0.0

nrk 1

cf1 8.3000e5 ef1 1.5780e+4 zf1 0.0

cb1 0.0 eb1 0.0 zb1 0.0

am1 1 2 0 0 0

bm1 0 0 0 1 2

ae1 1.000 1.000 0.000 0.000 0.000

be1 0.000 0.000 0.000 0.000 0.000

nre 0

if you need to see my chem.f subroutine is:

subroutine chem c c ================================================== ==================== c c calculates the change in species densities and internal energy c due to kinetic chemical reactions c c chem is called by: kiva c c chem calls the following subroutines and functions: (none) c c ================================================== ==================== c

implicit double precision (a-h,o-z)

include 'cvmg.inc'

include 'common.inc'

dimension domega(lnrk)

double precision kf,kb c c <><><><><><><><><><><><><><><><><><><><><><><><><> <><><><><><><><><><> c

modmh=1

cebu=1.0

amh=4.

bmh=0.5 c

tchem=1.0d-10

do 100 k=1,nz

i4b=(k-1)*nxpnyp

do 90 j=1,ny

i4=i4b+(j-1)*nxp+1

do 80 i=1,nx

if(f(i4).eq.0.) go to 80

tijk=temp(i4)

if(tijk.lt.tcut) go to 80

rtijk=1./tijk c++ EBU

roijk=ro(i4)

rtturi4=cebu*eps(i4)/tke(i4) c++

do 70 ir=1,nrk

rp=1.

pp=1.

ne=nelem(ir)

do 20 kk=1,ne

isp=cm(kk,ir)

rom=spd(i4,isp)*rmw(isp)

if(am(isp,ir).eq.0) go to 10

if(rom.le.0.) rp=0.

if(rom.gt.0.) rp=rp*rom**ae(isp,ir)

10 if(bm(isp,ir).eq.0) go to 20

if(rom.le.0.) pp=0.

if(rom.gt.0.) pp=pp*rom**be(isp,ir)

20 continue

kb=0.

kf=0.

teback=1.

teford=1.

ekback=1.

ekford=1.

if(cb(ir).le.0.) go to 30 c +++ c +++ backward reaction coefficient c +++

if(eb(ir).ne.0.) ekback=dexp(-eb(ir)*rtijk)

if(zetab(ir).ne.0.) teback=tijk**zetab(ir)

kb=cb(ir)*teback*ekback

30 if(cf(ir).le.0.) go to 40 c +++ c +++ forward reaction coefficient c +++

if(ef(ir).ne.0.) ekford=dexp(-ef(ir)*rtijk)

if(zetaf(ir).ne.0.) teford=tijk**zetaf(ir)

kf=cf(ir)*teford*ekford c +++ c +++ Magnussen ebu model

if(modmh.eq.1) then

tauchm=mw(2)/(roijk*kf)

if(rtturi4*tauchm.lt.1.)then

kf=amh*rtturi4

rp=dmin1(spd(i4,1)/(am(1,1)*mw(1)),spd(i4,2)/(am(2,1)*mw(2)),

1 bmh*(spd(i4,4)+spd(i4,5))/(bm(4,1)*mw(4)+bm(5,1)*mw(5)))

endif

endif c +++ c +++ if any rate coefficients cannot be put in standard c +++ form, code them by hand and put them here c +++ c +++ find the reference species (the one in greatest danger c +++ of being driven negative) c +++

40 omeg=kf*rp-kb*pp

rmin=0.

if(omeg.le.1.d-30) go to 70

do 50 kk=1,ne

isp=cm(kk,ir)

if(spd(i4,isp).le.0.) go to 50

rom=omeg*fbmam(isp,ir)*mw(isp)/spd(i4,isp)

if(rom.ge.0.) go to 50

if(rom.lt.rmin) iref=isp

rmin=dmin1(rmin,rom)

50 continue

rom=spd(i4,iref)*rmw(iref)

flam=fam(iref,ir)

flbm=fbm(iref,ir)

ctop=flam*kb*pp + flbm*kf*rp

cbot=flam*kf*rp + flbm*kb*pp

domega(ir)=rom*dt*(ctop-cbot)/((rom+dt*cbot)*(flbm-flam))

do 60 isp=1,nsp

spd(i4,isp)=spd(i4,isp)+mw(isp)*fbmam(isp,ir)*dome ga(ir)

60 continue c

dechem=qr(ir)*domega(ir)/ro(i4)

dechk=dabs(dechem/sie(i4))

sie(i4)=sie(i4)+dechem

tchem=dmax1(tchem,dechk) c

civaomega(i4)=domega(ir)/dt c

70 continue

80 i4=i4+1

90 continue 100 continue

write(*,*)ncyc,tchem c +++ c +++ ignition -- single point, dual point, or ring c +++

if(t.lt.t1ign .or. t.gt.t2ign) return

diignl=dfloat(iignl(2))

nspark=cvmgzi(1,2,diignl)

do 140 n=1,nspark

do 130 k=kignb(n),kignt(n)

i4k=(k-1)*nxpnyp

do 120 j=jignf(n),jignd(n)

i4jk=i4k+(j-1)*nxp

do 110 i=iignl(n),iignr(n)

i4=i4jk+i

if(temp(i4).lt.1600.) sie(i4)=sie(i4)*(1.+xignit*dt) 110 continue 120 continue 130 continue 140 continue

return

end

Your help will be very helpful to me.



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