Numerical Study on the Low Emission Window of HCCI Combustion Sung Wook Park and Rolf D. Reitz Sponsor : Diesel Emissions Reduction Consortium

Engine Research Center UW-Madison Objectives and calculation conditions Low Emission Window Diesel emissions such as CO, NO and soot are highly dependent on equivalence ratio and temperature. Emission levels on (equivalence ratio)-T (peak cycle temperature) map can provide information on the optimal HCCI engine operation conditions. Effects of IVC timing, EGR, intake temperature, engine load and engine speed on the emission- -T maps are studied. Calculation conditions Motivation & Objectives Engine specification - Bore x stroke : 82.0 x 90.4 mm - Compression ratio : 16.0:1 - Displacement : 477cm 3 Code : KIVA-3V with CHEMKIN chemistry solver 2-D computational mesh at TDC Operating conditions - Assume ideally homogeneous charge at IVC - Fuel amount : 20, 25, 30 mg - Engine speed : 1,000, 2,000, 3,000 rpm - EGR : 0-70% - T in : K - Equivalence ratio :

Effect of IVC timing on CO and NO emissions IVC : -100 o ATDC IVC : -130 o ATDC IVC : -115 o ATDC IVC : -142 o ATDC - Fuel amount : 20.0 mg - Engine speed : 2,000 rpm

Retarded IVC timing Phi=0.6, EGR 50%Phi=1.0, EGR 50% - Engine speed : 2,000 rpm - Fuel amount : 20.0 mg Effect of intake temperature on SOC and P in

Engine Research Center UW-Madison Effect of intake temp. on emissions and peak cycle temp. Phi=0.6 Phi=1.0 - Fuel amount : 20.0 mg - Engine speed : 2,000 rpm - EGR : 50%

Stat of combustion (30% accumulated heat release) IVC : -130 o ATDCIVC : -142 o ATDC - Fuel amount : 20.0 mg - Engine speed : 2,000 rpm IVC : -100 o ATDCIVC : -115 o ATDC

Engine Research Center UW-Madison Effect of engine speed and fuel amount on emissions Effect of engine speed - IVC : -142 o ATDC - Fuel amount : 20.0 mg - IVC : -130 o ATDC - Engine speed: 2,000 rpm Effect of fuel amount