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Mechanisms of NH₃ generation using LNT-like catalysts have been studied in a bench reactor over a wide range of temperatures, flow rates, reformer catalyst types and synthetic exhaust-gas compositions. The experiments showed that the on board production of sufficient quantities of ammonia on board for SCR operation appeared feasible, and the results identified the range of conditions for the efficient generation of ammonia. In addition, the effects of reformer catalysts using the water-gas-shift reaction as an in-situ source of the required hydrogen for the reactions are also illustrated. Computations of the NH₃ and NOx kinetics have also been carried out and are presented. Design and impregnation of the SCR catalyst in proximity to the ammonia source is the next logical step. A heated synthetic-exhaust gas flow bench was used for the experiments under carefully controlled simulated exhaust compositions.

The rotary engine provides high power density compared to piston engine, but one of its downside is higher oil consumption. In order to better understand oil transport, a laser induced fluorescence technique is used to visualize oil motion on the side of the rotor during engine operation. Oil transport from both metered oil and internal oil is observed. Starting from inside, oil accumulates in the rotor land during inward motion of the rotor created by its eccentric motion. Oil seals are then scraping the oil outward due to seal-housing clearance asymmetry between inward and outward motion. Cut-off seal does not provide an additional barrier to internal oil consumption. Internal oil then mixes with metered oil brought to the side of the rotor by gas leakage. Oil is finally pushed outward by centrifugal force, passes the side seals, and is thrown off in the combustion chamber.

This work examines the effect of valve timing during cold crank-start and cold fast-idle (1200 rpm, 2 bar NIMEP) on the emissions of hydrocarbons (HC) and particulate mass and number (PM/PN). Four different cam-phaser configurations are studied in detail: 1. Baseline stock valve timing. 2. Late intake opening/closing. 3. Early exhaust opening/closing. 4. Late intake phasing combined with early exhaust phasing. Delaying the intake valve opening improves the mixture formation process and results in more than 25% reduction of the HC and of the PM/PN emissions during cold crank-start. Early exhaust valve phasing results in a deterioration of the HC and PM/PN emissions performance during cold crank-start. Nevertheless, early exhaust valve phasing slightly improves the HC emissions and substantially reduces the particulate emissions at cold fast-idle.

The gasoline direct injection (GDI) engine particulate emission sources are assessed under cold start conditions: the fast idle and speed/load combinations representative of the 1st acceleration in the US FTP. The focus is on the accumulation mode particle number (PN) emission. The sources are non-fuel, combustion of the premixed charge, and liquid fuel film. The non-fuel emissions are measured by operating the engine with premixed methane/air or hydrogen/air. Then the PN level is substantially lower than what is obtained with normal GDI operation; thus non-fuel contribution to PN is small. When operating with stoichiometric premixed gasoline/air, the PN level is comparable to the non-fuel level; thus premixed-stoichiometric mixture combustion does not significantly generate particulates. For fuel rich premixed gasoline/air, PN increases dramatically when lambda is less than 0.7 to 0.8.

It is well known that lubricating oil consumption (LOC) is much affected by the cylinder bore deformation occurring within internal combustion engines. There are few analytical reports, however, of this relationship within internal combustion engines in operation. This study was aimed at clarifying the relationship between cylinder bore deformation and LOC, using a conventional in-line four-cylinder gasoline engine. The rotary piston method developed by the author et al. was used to measure the cylinder bore deformation of the engine’s cylinder #3 and cylinder #4. In addition, the sulfur tracer method was applied to measure LOC of each cylinder. LOC was also measured by changing ring tension with a view to taking up for discussion how piston ring conforms to cylinder, and how such conformability affects LOC. Their measured results were such that the cylinder bore deformation was small in the low engine load area and large in the high engine load area.

This paper quantifies the potential of electric propulsion systems to reduce petroleum use and greenhouse gas (GHG) emissions in the 2030 U.S. light-duty vehicle fleet. The propulsion systems under consideration include gasoline hybrid-electric vehicles (HEVs), plug-in hybrid vehicles (PHEVs), fuel-cell hybrid vehicles (FCVs), and battery-electric vehicles (BEVs). The performance and cost of key enabling technologies were extrapolated over a 25-30 year time horizon. These results were integrated with software simulations to model vehicle performance and tank-to-wheel energy consumption. Well-to-wheel energy and GHG emissions of future vehicle technologies were estimated by integrating the vehicle technology evaluation with assessments of different fuel pathways. The results show that, if vehicle size and performance remain constant at present-day levels, these electric propulsion systems can reduce or eliminate the transport sector's reliance on petroleum.

This article reports on the potential of negative valve overlap (NVO) for improving the net indicated thermal efficiency (η NIMEP) of gasoline engines during part load. Three fixed fuel flow rates, resulting in indicated mean effective pressures of up to 6 bar, were investigated. At low load, NVO significantly reduces the pumping loses during the gas exchange loop, achieving up to 7% improvement in indicated efficiency compared to the baseline. Similar efficiency improvements are achieved by positive valve overlap (PVO), with the disadvantage of worse combustion stability from a higher residual gas fraction (xr). As the load increases, achieving the wide-open throttle limit, the benefits of NVO for reducing the pumping losses diminish, while the blowdown losses from early exhaust valve opening (EVO) increase.

Inorganic engine lubricant additives, which have various specific, necessary functions such as anti-wear, leave the combustion chamber bound to soot particles (approximately ≤1% by mass) as ash [13], and accumulate in aftertreatment components. The diesel particulate filter (DPF) is especially susceptible to ash-related issues due to its wall-flow architecture which physically traps most of the soot and ash emissions. Accumulated lubricant-derived ash results in numerous problems including increased filter pressure drop and decreased catalytic functionality. While much progress has been made to understand the macroscopic details and effects of ash accumulation on DPF performance, this study explores the nano- and micron-scale forces which impact particle adhesion and mobility within the particulate filter.

Particulate emissions from a production gasoline direct injection spark ignition engine were studied under a typical cold-fast-idle condition (1200 rpm, 2 bar NIMEP). The particle number (PN) density in the 22 to 365 nm range was measured as a function of the injection timing with single pulse injection and with split injection. Very low PN emissions were observed when injection took place in the mid intake stroke because of the fast fuel evaporation and mixing processes which were facilitated by the high turbulent kinetic energy created by the intake charge motion. Under these conditions, substantial liquid fuel film formation on the combustion chamber surfaces was avoided. PN emissions increased when injection took place in the compression stroke, and increased substantially when the fuel spray hit the piston.

A dynamometer-mounted four-cylinder Saturn engine was used to accumulate combustion chamber deposits (CCD), using an additized fuel. During each deposit accumulation test, the HC emissions were continuously measured. The deposit thickness at the center of the piston was measured at the beginning of each day. After the 50 and 35-hour tests, HC emissions were measured with isooctane, benzene, toluene, and xylene, with the deposited engine, and again after the deposits had been cleaned from the engine. The HC emissions showed a rapid rise in the first 10 to 15 hours and stabilization after about 25 hours of deposit accumulation. The HC increase due to CCD accumulation accounted for 10 to 20% of the total engine-out HC emissions from the deposit build-up fuel and 10 to 30% from benzene, isooctane, toluene, and xylene, making CCDs a significant HC emissions source from this engine. The HC emissions stabilized long before the deposit thickness.

The purpose of this study is to clarify the state of heat loss to the cylinder liner of the tested engine of which piston and cylinder head were previously measured. The authors' group developed an original measurement technique of instantaneous surface temperature at the cylinder liner wall using thin-film thermocouples. The temperature was measured at 36 points in total. The instantaneous heat flux was calculated by heat transfer analysis using measurement results of the temperature at the wall. As a result, the heat loss ratio to all combustion chamber walls is evaluated except the intake and exhaust valves.

The characteristics of the early development of fuel sprays from pressure swirl atomizer injectors of the type used in direct injection gasoline engines is investigated. Planar laser-induced fluorescence (PLIF) was used to visualize the fuel distribution inside a firing optical engine. The early spray development of three different injectors at three different fuel pressures (3, 5, and 7 MPa) was followed as a function of time in 30 μsec intervals. Four phases could be identified: 1) A delay phase between the rising edge of the injection pulse and the first occurrence of fuel in the combustion chamber, 2) A solid jet or pre-spray phase, in which a poorly atomized stream of liquid fuel during the first 150 μsec of the injection. 3) A wide hollow cone phase, separation of the liquid jet into a hollow cone spray once sufficient tangential velocity has been established and 4) A fully developed spray, in which the spray cone angle is narrowed due to a low pressure zone at the center.

Hydrogen can be readily used in spark-ignition engines as a clean alternative to fossil fuels. However, a larger burning velocity and a shorter quenching distance for hydrogen as compared with hydrocarbons bring a larger cooling loss from burning gas to the combustion-chamber wall. Because of the large cooling loss, the thermal efficiency of a hydrogen-fueled engine is sometimes lower than that of a conventionally fueled engine. Therefore, the reduction of the cooling loss is very important for improving the thermal efficiency in hydrogen-combustion engines. On the other hand, the direct-injection stratified charge can suppress knocking in spark-ignition engines at near stoichiometric overall mixture conditions. Because this is attributed to a leaner end gas, the stratification can lead to a lowered temperature of burning gas around the wall and a reduced cooling loss.

The results of this study make clear the characteristics of electrode performance deterioration in terms of cell voltage reduction in polymer electrolyte fuel cells (PEFCs) caused by the presence of certain quantities of carbon monoxide and/or hydrogen sulfide in the anode feed. AC impedance measurements of the anode and cathode potentials revealed that both electrode potentials showed deterioration in the presence of each type of poisoning gas. This suggests that the poisoning gases permeated the electrolyte membrane and transferred to the cathode, causing performance deterioration by poisoning the catalyst. In addition, AC impedance measurements indicated that the presence of hydrogen sulfide in the anode feed increased the membrane impedance, thus implying some poisoning effect even on the electrolyte membrane.

Aldehydes are the cause of sick house syndrome or chemical sensitivity and have harmful influences for human beings. In the cabin of vehicle, aldehydes which are included in the volatilization gas from the interior materials, DE emission gas in intake air, cigarette smoke and so on spoil the comfortableness. Active carbon, which has been used as an adsorbent, shows an excellent removal efficiency for most of the gas components by physical adsorption. But for aldehydes, it has difficulty because aldehydes are hard to be adsorbed physically. We have developed new aldehydes adsorbent undergoing addition reaction with gaseous aldehydes on its surface. Aldehydes capture material (ACM) make use of the chemical reaction using a resorcin as a reagent and an H-type zeolite as a water-containing support, and active hydrogen is used as a catalyst to promote the reaction. In addition, we have applied ACM to cabin air filter (CAF) of vehicle.

Reformed fuel from hydrocarbons or alcohol mainly consists of hydrogen, carbon monoxide and carbon dioxide. The composition of the reformed fuel can be varied to some extent with a combination of a thermal decomposition reaction and a water gas shift reaction. Methanol is known to decompose at a relatively low temperature. An application of the methanol reforming system to an internal combustion engine enables an exhaust heat recovery to increase the heating value of the reformed fuel. This research analyzed characteristics of combustion, exhaust emissions and cooling loss in an internal combustion engine fueled with several composition of model gases for methanol reformed fuels which consist of hydrogen, carbon monoxide and carbon dioxide. Experiments were made with both a bottom view type optical access single cylinder research engine and a constant volume combustion chamber.

This study analyzes the factors influencing the thermal efficiency of a homogeneous charge spark-injection (SI) engine fuelled with hydrogen, focusing on the degree of constant volume and cooling loss. The cooling loss from the burning gas to the cylinder walls is quantitatively evaluated by analyzing the cylinder pressure diagram and exhaust gas composition. The degree of constant volume burning and constant volume cooling are also obtained by fitting the Wiebe function to the rate of heat release calculated using the cylinder pressure diagram. A comparison of combustion and cooling characteristics of hydrogen and methane combustion reveals that cooling loss in hydrogen combustion is higher than that of methane combustion due to the short quenching distance and rapid burning velocity during hydrogen combustion. It is also suggested that the high cooling loss observed during hydrogen combustion reduces thermal efficiency.

Although various factors affecting oil consumption of an internal combustion engine can be considered, a technique to predict the amount of oil consumed within a cylinder that passes across a running surface of a ring was developed in this study. In order to predict the effect of cylinder deformation on oil consumption, a simple and easy technique to calculate the oil film thickness in deformed cylinder was proposed. For this technique, the piston ring was assumed to be a straight beam, and the beam bends with ring tension, gas pressure, and oil film pressure. From the calculated oil film thickness, amount of oil passing across the running surface of the TOP ring and into the combustion chamber was calculated. The calculated results were then compared to the oil film thickness of the ring and oil consumption measured during engine operation, and their validity was confirmed.

Both NOx and unburned HC were reduced by changing the direction of the flame propagation. It is generally said that the optimum ignition position of spark ignition engine is in the center of combustion chamber. However by igniting arround the chamber and propagating the flame toward the center, a smooth heat release pattern due to the decrease in the flame area and a decrease in the unburned gas entering the ring crevise can be anticipated. These effects of this combustion process, which was named the surrounding combustion process (SCP), were experimntally confirmed using the constant volume combustion vessels and the spark ignition engine equipped with six spark plugs per cylinder. Next, the steps for decreasing the number of ignitions TCre considered, and additional three spark plugs for SCP were installed in the four valve pentroof combustion chamber. With this engine, the NOx reduction and the capability of SCP to further improve the lean burn engine fuel economy were confirmed.

Mazda announced that all customers who purchase Mazda cars are provided with the joy of driving and excellent environmental and safety performance under slogan of "Sustainable Zoom-Zoom" long-term vision for technology development. The purpose of this study is to develop a new approach of Life Cycle Assessment (abbreviated to LCA) to be applied to clean energy vehicles and new car models. The improvement of both environmental performance, e.g., fuel consumption, exhaust emissions, vehicle weight reduction, and LCA that is a useful methodology to assess the environmental load of automobiles for their lifecycles has become more important. LCA by inventory analysis, for RX-8 Hydrogen RE as a rotary engine vehicle used hydrogen as clean energy, was carried out and disclosed the world for the first time. LCA for new Mazda 5 was carried out as the portfolio of all models, previously only the specific model equipped with fuel efficiency device based on ISO14040.