Learning Forum

[Nick Pester]

Hello,

I am attempting to fully decode the internal structure of an exported FGM PDF table generated in Fluent 2023R1 (Partially Premixed FGM model). I exported the table to text format and manually analysed all block IDs and dimensions.

Below is a structured summary of what I have identified (I kept the points very low so I can go over the table in reality my table is more refined).

From the table export:

• Block 201 (9) → Mean mixture fraction 

• Block 202 (3) → Mixture fraction variance 

• Block 291 (10) → Progress variable variance

• Block 262 (8) → Mean progress variable 

• (pdf/numenthalpy 13) → 13 enthalpy slices

• Block 293 (293 9 3 13 8) → mean temperature
• Block 295 → mean density 
• Block 354 is laminar viscosity 
• Block 356 is thermal conductivity 

I would appreciate clarification on several remaining points.

1) What do blocks 297, 312, 236, 237 represent? 
2) In block 312 I have (312 9 3 10 8 2) what is the last 2 representing? (pdf/n-table-scalars 2) what are these scalars? 
3) In block 299 which is suspect is mean rate of reaction progress what is the 7 representing (299 9 3 10 8 7)? Is it species + scalar? 
4) In the PDF Table Viewer, I can plot the mass fraction of the species but I cant see their values stored in the pdf file how are they shown in the pdf viewer if not stored in the file?
5) Is temperature and density PDF-integrated over mixture fraction only, or over both mixture fraction and progress variable PDFs?
6) for a given block (293 9 3 13 8) is the storage order equivalent to nested loops? so in this case:
for Z̄:
  for Zvar:
    for H:
      for c̄:
         write value

Thank you for your help!!! 

here is a snip of the first part of the pdf file:

(0 "Fluent2023R1")

(0 "PDF Variables:")
(100 (101)(
(pdf/includeequil? #t )
(pdf/frozenboundary? #f )
(pdf/multi? #f )
(pdf/adiabatic? #f )
(pdf/chemistry 6)
(pdf/empirialfuel? #f )
(pdf/empirialscnd? #f )
(pdf/parpremix #t )
(pdf/numspecies 6)
(pdf/initpressure 101325.000000)
(pdf/mintemp 270.000000)
(pdf/maxtempratio 1.000000)
(pdf/tloss 0.667000)
(pdf/tadd 0.250000)
(pdf/max-species 6)
(pdf/num-include-species 0)
(pdf/num-exclude-species 18)
(pdf/mole-or-mass? #f )
(pdf/exclude-species c no no2 n2o h2o n nh nh2 nh3 nnh hcn hno cn h2cn hcnn hcno hocn hnco )
(pdf/include-species )
(pdf/stream1temp 298.000000)
(pdf/stream2temp 298.000000)
(pdf/stream3temp 300.000000)
(pdf/numf1point 9)
(pdf/numf2point 8)
(pdf/richlimit1 1.000000)
(pdf/richlimit2 1.000000)
(pdf/numfvpoint 3)
(pdf/premix-flamelet #t )
(pdf/numfv2point 10)
(pdf/numstream 2)
(pdf/betapdf? 1)
(pdf/empshfuel 50000000.000000)
(pdf/empcpfuel 1000.000000)
(pdf/empshscnd 50000000.000000)
(pdf/empcpscnd 1000.000000)
(pdf/numenthalpy 13)
(pdf/nne/cold 9)
(pdf/nne/hot 4)
(pdf/thermo-file-name D:/thermo30.dat )
(pdf/numfl 8)
(pdf/expinv 1.000000)
(pdf/scadmx 1.000000)
(pdf/flamelet-int-params 8 8)
(pdf/flamelet-real-params 1.000000e-04 5.000000e+00 1.000000e+00 2.000000e+00 1.000000e-05 1.000000e-15 1.000000e-05 1.000000e+04)
(pdf/flamelet-mechanism-file-name D:grimech30.dat )
(pdf/flamelet-thermo-file-name D:thermo30.dat )
(pdf/flamelet-auto-refine? #f )
(pdf/flamelet-auto-refine/value 0.500000)
(pdf/flamelet-auto-refine/slope 0.500000)
(pdf/flamelet-auto-refine/init-pts 64)
(pdf/flamelet-auto-refine/max-pts 64)
(pdf/fgm-nonad-5d? #f )
(pdf/num-nonad-fla 21)
(pdf/strained-fla? #f )
(pdf/strained-fla-nh 1)
(pdf/strained-fla-nf 32)
(pdf/strained-fla-nx 250)
(pdf/fla-sl-available? #f )
(pdf/fla-sl-nh 1)
(pdf/fla-sl-nf 1)
(pdf/fla-sl-nspe 1)
(pdf/fsto 0.252014)
(pdf/n-table-scalars 2)
(pdf/lam-prop-table? #t )
(pdf/fgm-flamelet-type 2)
(pdf/fgm-num-scalars 0)
))

(0 "Species Input Data:")
(100 (102 6)(
n2
ch4
o2
h2o
h2
co
))