INITFLAM

INITFLAM is a tool (pre-processor software) to compute an asymptotic premixed 1D flame solution. This asymptotic solution is then used to produce a restart file for NTMIX3D (1D geometry). All the files required can be loaded from the File access section.
  INITFLAM produces 1D premixed flame for one step irreversible chemistry with deficient fuel. The reaction rate is expressed in terms of \alpha and \beta parameters. Rough assumptions are used, derived from analytical solution: constant pressure, constant physical parameters (versus temperature etc...) and unity Lewis number for each species. For each species the molecular diffusivity Dk are then the same (same Lewis number).

All the variables are reduced: non-dimensionalisations are different between INITFLAM and NTMIX3D. For more details see the QPF...

This tool is written in Fortran and it is encapsulated in UNIX scripts for compilation and execution. This section gives input files example (for INITFLAM and NTMIX3D) and describes how to use the UNIX scripts.
  1/ Specifying constants: the run parameters for INITFLAM are stored in a file called *.ini and include \alpha, \beta and reduced flame consumption speed. INITFLAM input file looks like this (example: 1tp.ini):

Flamme au Reynolds simule de la manip
7.5d-1  alpha
8.0d0    beta
2.     Xmax Xmax for vertical flames or 2*Ymax for horizontal flames (taille du domaine de TMIX)
1.      Xstart position de la flamme dans le canal
0.75d0  pR Prandtl=Pr/5
2000  Re de TMIX definit la viscosite par Re=a(sound) L/nu
0.01 Flame_speed de TMIX
1.      po
1.      usl
1.      htot
401     Nx
401     ntau
1.000   tauign
6       iout
1       Idomain 0: de -Xmax/2 a Xmax/2      * 1: de 0 a Xmax
1       Igridy  0: grille irreg             * 1: reg
0       Iy
2.2     By

2/ Producing restart file: tcsh crun.cmd
This command needs you to choice an input file (for example the one described previously: 1tp.ini). Then the program INITFLAM reads this file and produced a temporary file named fort.55 containing the asymptotic solution. A copy is stored in a file named 1tppro.dat. Finally, the asymptotic temperature profile from INITFLAM is transformed into a restart file for NTMIX3D by INIT1NTMIX. INIT1NTMIX ask you if you want a stationary solution or not (also different Lewis numbers can be attributed) and then produces the NTMIX3D restart file.
Because this is an interactive part, the output screen is reported below. Be careful, you have to remember the chemistry parameter values (Tact and Astar) necessary in TEST_IN file if you used diffus option for NTMIX3D compilation:


 Starting INITFLA.COM procedure for YMP:
 

 INIT FILES for INITFLA computations:
1tp.ini              401-0.038-2.ini      401-0.038-4b.ini     401-0.038-4d.ini
201-0.038-2.ini      401-0.038-3.ini      401-0.038-4c.ini     551-0.038-4b.ini
401-0.038-1.ini      401-0.038-4.ini      401-0.038-4cBIS.ini

 YOUR CHOICE without .INI extension: (or CTRL C to quit)

1tp
 The choice of Igridy first. You chose 1 regular grid
  I force By and n at zero
  Valeur de Xmax en unite de flamme:   30.00000
  La position initiale du front    :   15.00000
  Idomain is :   1
  The grid is regular
          Point    s     X(CHRIS)   DeltaX(CHRIS)
 Domaine de calcul en unite de TMIX    :   2.000000
 Mini, maxi et rapports du pas d espace:   1.666653E-02  1.666679E-02  1.000015
  Dalam1 =   156.9920
 shooting iteration: i,p,y(nx)    1    0.15699E+03   -0.84728E-01
 shooting iteration: i,p,y(nx)    2    0.15542E+03   -0.80069E-01
 shooting iteration: i,p,y(nx)    3    0.12844E+03    0.38193E-02
 shooting iteration: i,p,y(nx)    4    0.12967E+03   -0.17086E-03
 shooting iteration: i,p,y(nx)    5    0.12962E+03   -0.25798E-06
 ignition temp, flame eigenvalue =   0.100000000000E+01  0.129616379000E+03
     /!\ nx max en dur 801
 1/  Pour uentree=SL (cas stationnaire)
 2/  Pout uentree=0  (cas instat.)
 Votre Choix ?
?1
 Le1  ?
?1.
 Le2 (h2=0.3) ?
?1.
 damla =   129.6164000000000
 taille du domaine=  2.000000000000000   Astar=  834114.3655554274
 T2=  10.00000000000000                  Tact=  106.6666666666667
 Heat_release=   67.02412868632709
 Re          =   2000.000000000000
 Pr          =   0.7500000000000000
 /!\ Les Schmidt sont :   0.7500000000000000  0.7500000000000000
 ngrid            =  121   ------------------------------
 Maxi tau du fuel            :   2.378229190123251D-02
 Maxi tau THEORIE p42 Poinsot:   2.501132811290268D-02
 tautot                      :   1.029078269060480D-03
 vitesse de flamme (calculee avec tautot) :  9.196409911174985D-03
 Flame_speed= (imposee)                   :  9.999999000000000D-03

Creation du fichier restart NTMIX: restart.p000.r8
Creation du fichier(alpha beta):  resuWreduced.dat
A transferer  au-dessus OU /workdir/rech/sot/rsot161 --------------


Files produced are binary (restart file) or ascii (*.dat file).

3/ Running NTMIX3D: In order to run NTMIX3D you must have an NTMIX3D input file (TEST_IN) matching the restart file. NTMIX3D must be also compiled with specific physical models described in param.defs. See File access section.

4/ Visualization and analysis procedures can be found in Post treatment part. By sake of simplicity some of them have been reported here:
(I have to do this...)
 

UNIX Scripts
    compil.cmd
    crun.cmd

Fortran sources
    initfla.f
    fiv2.f
    ode.f
    init1ntmix.f

Inputs for INITFLAM and NTMIX3D, param.defs file for NTMIX3D (Example)
    1tp.ini
    TEST_IN
    param.defs

DCpremix

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