KIVA III V

1
KIVA III (V)

• 2003.07.31
• A/F, Swirl, Tumble, EGR ( Engine Parameter )

2
Equivalence Ratio

• Air-fuel ratio A
• - Stoichiometric ratio As
• Fuel-Air ratio F
• - Stoichiometric ratio Fs

3
Equivalence effect 1

• CO, H2 increase with E.R.?
• O2, NO, OH, O decrease with E.R?
• E.R. gt4
• C(s), HCN, C2H2, CH4 with E.R. ?
• Maximum Power limit because of solid carbon
  (smoke soot)
• E.R. ? ? Ignition Delay ?

4
EGR (Exhaust Gas Recirculation)
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EGR Effect

• Controlling exhaust emission of NOx.
• Slow cool combustion process in temperature
• Too much flow decrease the performance of engine
  (mistfire)
• Too much flow increase the HC, PM
• Too little flow induce the knocking
• Engine RPM ? EGR flow quantity
• Reduce the volatility of the air/fuel charge
• Reduce the flame speed

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Swirl / Tumble

• Fuel around outside of the cylinder
• Incomplete combustion
• Induce the stratification
• Make the eddy for mixing the fuel air
• Tumble increase the turbulent level at the end of
  compression stroke

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Stratification
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Stratification 2
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Stratification 3
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N-Heptane / Iso - Octane
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Tumble ( Rotation )