Recent Progress on ISAT

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Recent Progress on ISAT

• Stephen B. Pope
• January 25, 2007

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Research Group Meetings

• Practice talks
• e.g. for upcoming Combustion Institute meeting
• Report and discussion of recent research

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In Situ Adaptive Tabulation

• Particle methods
• 1010 particle steps
• Reaction sub-step direct integration 104 ms
• 108 s 3.2 years
• X 1,000 speed-up -gt 28 hrs
• ISAT
• Tabulate results of ODE integration

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ISAT-CK 5.1

• Primary retrieve
• BT, MRU, MFU
• Secondary retrieve
• EBT in affine space
• can afford to be complete
• Grow
• EOA/EOI
• EBT
• Add
• EOI initialized to exclude existing points

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Very Recent Additions

• de_nearby
• Location (x) of direct evaluation may be slightly
  different from the query location
• Needed for ICE-PIC/ISAT
• Slow progress
• Query time gt DE time
• Reduce growing
• Worst case query time 2 x DE time

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Preliminary Testing of ISAT-CK 5.1

• Systematic testing to be performed by Liuyan
• Study performance as function of parameters
• Error tolerance
• Available storage

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Test YF varying error tolerance

• Skeletal mechanism (16 species)
• CPU for DI 5,000 ms
• Premixed
• Storage 1.2 Gbytes
• Idites1000 (affects performance)
• Q107
• Etol2-p, p1,2,,32

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CDF of error for etol1.2e-4
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Test YF observations

• Error well controlled down to 1e-8 confirmed
  that errors due to ODE
• Timing affected by error testing
• Speed-up on table filling

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Test YH varying number of leaves

• Skeletal mechanism (16 species)
• CPU for DI 5,000 ms
• Premixed
• Q107
• Etol10-4
• Leaves 16, 32, 64,,2048.

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Test YH observations

• As storage decreases, query time tends to DE time
• Slow progress avoids excessive CPU time
• slow progress if query time gt DE time
• Ret_frac set to ½
• Grow_frac set to ½
• EOIs not shrunk

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Test YA varying error tolerance

• GRI 3.0 mechanism (53 species)
• CPU for DI 80,000 ms (x16 cf skeletal)
• Premixed
• Storage 1.2 Gbytes
• Idites1000 (affects performance)
• Q108
• Etol2-p, p1,2,,19

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Test YA Observations

• Error well controlled
• Even for smallest etol, retrieves dominate in the
  end but it takes longer to reach retrieving
  asymptote

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Test K Dim. Of Affine Space

• Skeletal mechanism (16 species)
• Premixed
• Storage 1.0 Gbytes
• Idites1000 (affects performance)
• Q1e7
• Etol1e-3
• Affine space, na1,2,3,15

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Test M Pair Cover

• Skeletal mechanism (16 species)
• Premixed
• Storage 2.5 Gbytes
• Idites1000 (affects performance)
• Q1e7
• Etol1e-4
• Pair_cover type of ellipsoid used to cover two
  other ellipsoids (in EBT)
• 1 spheroid (no shrinking)
• 2 ellipsoid (covariance algorithm)
• 3 ellipsoid (iterative algorithm)
• 4 spheroid (with shrinking)

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Test YJ storage and etol

• Skeletal mechanism (16 species)
• Premixed
• Idites10,000 Q1e7
• Etol 4-p 1, ¼, 1/16,,1.5e-5
• Leaves 4q 16, 64, 256,,16,384

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Test YI varying etol

• Skeletal mechanism (16 species)
• CPU for DI 5e3 ms
• Non-premixed, variable time step
• Idites10,000 Q1e8
• Storage 1.2 Gbytes
• etola 1, 1/2,...3e-5

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Future Plans ISATAB

• Single precision for ellipsoids
• x2f_mpi
• ISAT/ANN

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Future Plans ISAT-CK

• ICE-PIC
• CEQ in place of Stanjan
• ADIFOR for Jacobians
• LP for realizability
• Conservation correction for sensitivity matrix

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Future Plans papers

• Pope (2007) new algorithms
• Lu Pope (2007) performance of ISAT
• Lu, Lantz, Ren, Pope (2007) x2f_mpi
• Ren Pope (2007) ICE-PIC/ISAT