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Figure 3.28 Steady-state HC emissions as a function of spark timings at four locations unde A= 1.1 and 20° C fluids. — Figure 3 28 Steady-state HC emissions as a function of spark timings at four locations unde A= 1.1 and 20° C fluids.

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Figure 1.1. Cumulative engine-out and tailpipe-out HC emission over an FTP-75 for a six- cylinder SI engine.

igure 2.1 Intake charge motion control plate (CMCP) with 67% asymmetrical area reduction for the single cylinder engine. location of the spark retard ignition timing limit was extended.

ire 2.2 Fast-response HC analyzer probe sampling locations for single-cylinder experiments. Exhaust port and runner probes 7 cm and 37 cm from exhaust valves, respectively.

Figure 2.4 Overview of gas delivery system equipment used for quench gas and secondary air experiments.

Figure 2.5 Active three-way catalyst (serial no: XX901JP) specifications. Table 2.3. Multi-cylinder engine specifications.

Figure 2.6 Schematic of fast-response NDIR sampling head from Cambustion [8].

control plate (CMCP) installed in the intake port. a function of various spark timings and relative air/fuel ratios with and without the charge motiot

gure 3.3 Combustion durations as a function of spark timing for different relative air/fuel ratios and fluid temperatures without charge motion control plate (CMCP) at 3.0 bar Net-IMEP and 1500 RPM.

sure 3.4 Combustion duration as a function of spark timing for different relative air/fuel ratios and fluid temperatures with charge motion control plate (CMCP) at 3.0 bar Net-IMEP and 1500 RPM.

ire 3.5 Location of 50% MFB as a function of spark timing without charge motion control plate (CMCP) for various relative air/fuel ratios and fluid temperatures at 3.0 bar Net-IMEP and 1500 RPM.

igure 3.6 Location of 50% MFB as a function of spark timing with charge motion control plate (CMCP) for various relative air/fuel ratios and fluid temperatures at 3.0 bar Net-IMEP and 1500 RPM.

igure 3.7 Thermocouple measured port exit exhaust gas temperature as a function of 50% MEB location for various relative air/fuel ratios with and without the charge motion control plate (CMCP) at 3.0 bar Net-IMEP, 1500 RPM, and 20° C fluids.

gure 3.8 Converter-in sensible enthalpy rate as a function of COV of Net-IMEP for different relative air/fuel ratios with and without the charge motion control plate (CMCP).

‘igure 3.10 Steady-state HC flow rate and emission index HC emissions as a function of 50% MEB location for various relative air/fuel ratios and fluid temperatures at 3.0 bar Net-IMEP, 1500 RPM, with charge motion (CMCP). HC emissions.

‘igure 3.11 Typical time-resolved HC concentration profile measured in the exhaust port, 7 cm from the exhaust valves. Major features shown and noted during gas exchange, from exhaust valve opening (EVO) to exhaust valve closing (EVC).

Figure 3.12 In-cylinder pressure and exhaust port and runner time-resolved HC concentration measurements for three different spark timings (Sp = 15°, 0°, -16° BTDC) at 3.0 bar Net-IMEP, A = 1.0, CMCP, and 20° C fluids.

gure 3.13 In-cylinder pressure and time-resolve HC concentration measured in the port and runner for 90°, 40°, 20° C fluid temperatures, spark timing = -1° BTDC, A = 1.0, and without charge motion (CMCP). combined with the plug flow model, yielding a HC mass flow rate. sonditions that were required by the plug flow model. Data from the fast-response FID was the

Figure 3.15Engine cycle simulation thermodynamic model of open system, including crevices, work transfer to piston, and heat transfer to cylinder boundaries. temperatures.

manuals. Figure 3.16 GT-Power model of single-cylinder engine with intake and exhaust system.

‘igure 3.17 Port exit exhaust mass flow rate and exhaust gas temperature predicted by the engine model at the exit of the exhaust valves versus crank angle for various spark timings at 3.0 bar Net-IMEP, 1500 RPM, A = 1.0, and 20° C fluids.

Figure 3.18 Spatial and cyclic variations of the time-resolved HC measurements in the exhaust port, 7 cm from exhaust valves at several port-exit locations.

ire 3.19 Model results from analysis of HC measurements. GT-Power simulation results of in-cylinder pressure and exhaust mass flow rate at the port exit and runner. Measured HC concentration and resulting HC mass flow rate computed by a plug flow model.

Figure 3.20 Steady-state HC emissions as a function of spark timings measured in three locations under A = 1.0, 20° C fluids.

Figure 3.22 Steady-state HC emissions as a function of spark timing for three different locations under A = 1.1 and 20° C fluids.

Figure 3.23 Emission index HC emissions as a function of the location of 50% MFB for three different locations under A = 1.1 and 20° C fluid.

Figure 3.24 Phasing of quench gas injection as a function of crank angle. Data shown with in- cylinder pressure and solenoid trigger signal for 3.0 bar Net-IMEP, 15° BTDC spark timing, and A = 1.0.

Figure 3.25 Change in HC and NO, emissions as a function of the ratio of mass of quench gas to mass of charge (mCO2Quench/mCharge,j-+fye;) for three spark timings with A = 1.0 and 20° C fluids.

Figure 3.26 Steady-state HC emissions as a function of spark timing at four locations (cylinder exit, port exit, runner, and mixing tank) under A = 1.0 and 20° C fluids.

Figure 3.27 Emission index HC emissions as a function of 50% MFB location at four locations under A = 1.0 and 20° C fluids.

Figure 3.29 Emission index HC emissions as a function of 50% MFB location at four locations for A = 1.1 and 20° C fluids.

re 3.30 Exhaust secondary air injection experiments conducted at an engine relative air/ fuel ratio of 0.85 (engine) aS a function of with exhaust relative air/fuel ratio. Data shown for 3.0 bar’ Net-IMEP, 1500 RPM, 0° BTDC spark timing, and 20° C fluids.

ure 3.31 Hydrocarbon flow rate and runner exhaust gas temperatures as a function of various secondary air injection timings for a fixed engine (Agngine = 0.85) and exhaust stoichiometry (Acxhayst = 1.2). Data shown for 3.0 bar Net-IMEP, 1500 RPM, and 20° C fluids.

sure 4.1 Baseline calibration MAP, RPM, spark timing, and relative air/fuel ratio as a function of time after crank. Data from an ambient startup under idle load and speed conditions.

re 4.2 Spark timing as a function of time after startup for various spark modifications (A® spark): aggressive retarded spark timing modification, A@,,, = -15°

Figure 4.3 Measured UEGO relative air/fuel ratio (A) as a function of cycle no. after startup. Data shown for accelerated closed loop control compared to baseline calibration.

yure 4.4 COV of Net-IMEP as a function modified spark timing, 4 to 20 seconds after crank (130 cycles). In-cylinder pressure data acquired from all four cylinders at idle speed and load conditions following an ambient start.

ire 4.5 Location of 50% MFB as a function of cycle number after 20° C startup. Data shown for various spark timing modifications under idle speed and load conditions.

ire 4.6 Combustion duration (10-90%) as a function of cycle number after 20° C startup. Data shown for various spark timing modifications under idle speed and load conditions.

gure 4.7 Cylinder no. 4 port exit and converter-in hydrocarbon concentrations (ppmC 1) for the first 20 seconds following a 20° C start. Baseline timing and fueling calibration under idle load and speed conditions.

gure 4.8 Cylinder no. 4 pressure, CO, CO, and HC time-resolved concentrations measured at the exhaust port exit of cylinder no. 4 as a function of crank angle (CA). Data shown for three different spark modifications (absolute spark timings: 3°, -1°, -6° BTDC) from cycle 200 to 210, stoichiometric closed loop control and idle speed and load conditions (2.3 bar Net-IMEP, 1000 RPM, A= 1.0).Grayed areas show period of exhaust flow. flow.

igure 4.10 Cumulative, 1 to 20 seconds, ambient startup CO and HC mass emissions measured at the exhaust port exit of cylinder no. 4 and converter-inlet as a function of modified spark timing under idle speed and load conditions (Port exit emissions are scaled by a factor of 4 for comparison to converter-in levels).

concentrations for cylinders no. 3 and no. 4 for a spark timing of 3° BTDC under idle speed and

gure 4.12 Cylinder no. 3 and no.4 in-cylinder pressure and port exit time-resolved HC concentrations as a function of crank angle (CA). Data shown from cycle 200 to 210 after startup, absolute spark timing -4° BTDC, stoichiometric closed loop control, and idle speed and load conditions (2.3 bar Net-IMEP, 1000 RPM, A= 1.0).Grayed areas show period of exhaust flow.

igure 4.13 Port exit measured exhaust gas temperatures and relative air/fuel ratios (A) calculated from time-resolved CO and CO, measurements for cylinders no. 3 and no. 4 as a function of modified spark timing. Data shown for idle load and speed conditions under closed loop stoichiometric control.

Figure 4.14 Spark-ignition engine exhaust gas CO, and CO concentration data as a function of relative air/fuel ratio.

re 4.15 Converter-in CO + O, emissions and emission index HC levels as a function of intake MAP. Data shown for stoichiometric closed loop control and 20° C idle speed and load conditions (2.3 bar Net-IMEP, 1000 RPM, A = 1.0). CO+O, concentration shown with and without oxygen concentration corrections due to HC emissions.

‘igure 4.16 Measured exhaust gas and component temperatures as a function of time after crank, Data shown for baseline timing and fueling calibration under idle load and speed conditions. metal skin and component temperatures were observed to vary less than 20° C.

Figure 4.17 Cumulative converter-in feed gas HC emissions as a function of cumulative converter-in sensible enthalpy. Data shown for 1 to 20 seconds following an ambient startup for four spark timing modifications (A@,,,) under idle speed and load conditions.

igure 4.18 Cumulative HC mass emissions prior to catalyst light-off as a function of light- off time following an ambient start. Data shown for various spark modifications (A6,,,) under idle speed and load conditions (Light-off defined as 50% reduction in HC emissions).

gure 5.1 Plug flow exhaust oxidation sub-model flowchart with linked engine predicted cylinder-exit conditions, heat transfer, and chemical kinetic mechanism. each zone had a specific exhaust geometry and heat transfer correlation, Fig. 5.2.

Figure 5.2 Diagram of exhaust port and runner zones.

3 Simulation of single-cylinder exhaust mass flow versus crank angle after exhaust valve opening. Exhaust mass modeled using two elements; mass from compressible blown process and mass from incompressible displacement.

5.2.2 INITIAL CONDITIONS

figure 5.6 Mole fraction of exhaust gas composition for highly diluted reactive mixture of hydrocarbons.

7 Thermocouple measured exhaust gas and component temperatures for 15°,0°, and -15° BTDC spark timings. Steady-state warmed-up exhaust system with 20° C fluids, 3.0 bar Net-IMEP, 1500 RPM, and A = 1.0.

ple 5.2 Nusselt number correlations for exhaust runner with argument factors pulses and pipe bends [26, 27]. 5.3.3 AVERAGE EXHAUST HEAT TRANSFER COEFFICIENT

5.8 Average port (left) and runner (right) heat transfer coefficient as a function of spark timings. Data shown for mass elements from exhaust blowdown and displacement process.

5.9 Schematic of exhaust port and runner temperature validation of heat transfer sub- model. Exhaust port and runner HC oxidation modeled as a heat addition per unit length. Thermocouple modeled exhaust gas temperature at port exit and runner.

‘igure 5.10 Instantaneous exhaust gas, runner wall and thermocouple temperature as a function of time. Thermocouple response data shown for hot exhaust component temperatures.

‘igure 5.11 Thermocouple exhaust gas temperatures, measured versus modeled, for various spark timings. Comparison includes heat released due to exhaust system HC burn-up.

Figure 5.12 Cold-start SI engine-out speciated HC emissions for initial 63 seconds of engine operation using Japanese domestic fuel. Source: Yamamoto et al. [16].

Figure 5.13 Variation in engine-out hydrocarbon composition as a function of time durin; warm-up. Source: Kubo et al. [17].

Figure 5.14 Hydrocarbon oxidation pathways.

ure 6.1 Relative port, runner, and total exhaust system HC oxidation as a function of spark timing and relative air/fuel ratio. Data shown for 3.0 bar Net-IMEP, 1500 RPM, 20° C fluids, with intake charge motion (CMCP).

ire 6.2 Measured port and runner exhaust gas temperature as a function of spark timing and relative air/fuel ratio. Data shown for 3.0 bar Net-IMEP, 1500 RPM, 20° C fluids, with intake charge motion (CMCP).

ure 6.3 Measured and predicted fraction of port reacted hydrocarbons (left) and exhaust port time averaged and enthalpic gas temperatures (right) as a function of spark timing. Data shown for A = 1.0, 3.0 bar Net-IMEP, and 1500 RPM.

sure 6.4 Measured and predicted fraction of port reacted hydrocarbons (left) and exhaust port time averaged and enthalpic gas temperatures (right) as a function of spark timing. Data shown for 4 = 1.1, 3.0 bar Net-IMEP, and 1500 RPM.

ure 6.5 Measured and predicted fraction of runner reacted hydrocarbons (left) and exhaust runner time averaged and enthalpic gas temperatures (right) as a function of spark timing. Data shown for 4 = 1.0, 3.0 bar Net-IMEP, and 1500 RPM.

Figure 6.6 Measured and predicted fraction of runner reacted hydrocarbons (left) and exhaust runner time averaged and enthalpic gas temperatures (right) as a function of spark timing. Data shown for A = 1.1, 3.0 bar Net-IMEP, and 1500 RPM.

K showed modest burn up sensitivity (less than 10%) to temperature variations

Figure 6.10 Hydrocarbon mole fraction composition for three cases. Data shown for case 1 with the baseline HC mixture, case 2 is 100% iso-octane, and case 3 contains 55% ethylene, 35% pentane, and 10% methane. whereas, n-alkanes fragment into ethylene which reacts very rapidly to form highly reactive

igure 6.11 Calculated half-lives (t59) of various hydrocarbon mixtures as a function of temperature for exhaust residence times. Data shown for A = 1.0, 1% HC gas mixture.

CO, by 15 - 35%.

Figure 6.14 CO oxidation time constant as a function of exhaust relative air/fuel ratio (A) Data shown for three different spark timings (exhaust gas temperatures).

Figure 6.15 Measured time averaged and predicted adiabatic enthalpic runner gas temperatures as a function of exhaust relative air/fuel ratio (A).

Figure 6.16 Cylinder no. 4 port exit and collector-in exhaust mass flow rate as a function of crank angle. mixed, and subjected to a step change in air/fuel ratio at the runner collector before reaching the

Figure 6.17 Cylinder no. 4 port exit and collector-in exhaust gas temperature as a function of crank angle.

Figure 6.18 Diagram of multi-cylinder exhaust system with runner collector mixing.

Figure 6.19 Cylinder relative air/fuel ratio as a function of distance from exhaust valve seats.

‘igure 6.20 Measured and predicted fraction of runner reacted hydrocarbons (left) and exhaust runner time averaged and enthalpic gas temperatures (right) as a function of spark timing. Data shown for idle speed and load conditions, 1 to 20 seconds after 20° C startup. Model initial conditions based upon air/fuel ratio data from cylinder nos. 3 and 4.

between the two fired cylinders. cycle position is determined from spark discharge times differences

ure C.4.1 In-cylinder pressure and exhaust port and runner time-resolved HC concentration measurements for three different spark timings (Sp = 15°, -1°, -16° BTDC) at 3.0 bar Net-IMEP, A = 1.0, CMCP, and 90° C fluids.

sure C.5.1 Model results from analysis of time-resolved HC measurements. GT-Power simulation results of in-cylinder pressure (upper left) and exhaust mass flow rate at the port exit and runner.(upper right). Measured HC concentrations (lower left) and predicted HC mass flow rate (lower right). Data shown for 3.0 bar Net-IMEP, 1500 RPM., 15° BTDC spark timing, A = 1.0, and 20° C fluids.

igure C.7.2 Port exit and runner EGTs and tailpipe-out HC flow rate as a function of exhaust relative air/fuel ratio. Data shown for continuos secondary air injection at a fixed engine relative air/fuel ratio (Aengine = 9-85) and 0° BTDC spark timing.

zure D.1.1 In-cylinder pressure, RPM, MAP, spark timing, and lambda (A) as a function of time after ambient startup. Data shown for baseline spark and fuel calibration (A®.park = 0°). Calculated Net-IMEP and COV of Net-IMEP, averaged RPM, MAP, spark timing, and A, for 1 to 20 seconds after crank. ).1.1 In-cylinder Pressure, RPM, MAP, Spark Timing, and Relative Air/Fuel Ratic

ure D.3.1 In-cylinder pressure, RPM, MAP, spark timing, and lambda (A) as a function of time after ambient startup. Data shown for -10° spark timing modification (A®.park = -10°). Calculated Net-IMEP and COV of Net-IMEP, averaged RPM, MAP, spark timing, and A, for 1 to 20 seconds after crank. D.3.1 In-cylinder Pressure, RPM, MAP, Spark Timing, and Relative Air/Fuel Ratio

re D.3.2 Time-resolved port exit (FFID #1) and converter-in (FFID #2) HC concentrations, port exhaust gas temperature (EGT), and exhaust component temperatures as a function of time after ambient startup. Data shown -10° spark modification (A®spar, = -10°). Calculated sensible enthalpy and averaged HC concentrations for 1 to 20 seconds after crank.

ure D.4.1 In-cylinder pressure, RPM, MAP, spark timing, and lambda (A) as a function of time after ambient startup. Data shown for -15° spark timing modification (A® spark = -15°). Calculated Net-IMEP and COV of Net-IMEP, averaged RPM, MAP, spark timing, and A, for 1 to 20 seconds after crank.

Figure F.1.1| Exhaust gas hydrogen (H3) concentration as a function of CO concentration [14].

Port, runner, and calculated burn-up exhaust gas temperature as a function of combustion phasing (location of 50% MFB). Burn-up temperatures are based upon complete oxidation of HC without the effects of heat transfer in the runner. Data shown for 3.0 bar Net-IMEP, 1500 RPM, 20° fluids, 4 = 1.0 with charge motion (CMCP).

F.4.1 Spark Timing = 15° BTDC and A = 1.0 re F.4.1_ Time histories of cylinder-exit temperature, velocity, mass flow, and hydrocarbon mass emissions as a function of crank angle. Data shown for A = 1.0 and spark timing = 15° BTDC.

Figure F.4.2_ Mass element temperature and exhaust gas mole fraction histories as a function of time for a highly diluted reactive mixture. Data shown for A = 1.0 and spark timing = 15° BTDC.