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This paper presents the first results of an experimental study into a hybrid combustion concept for next-generation heavy-duty diesel engines. In this hybrid concept, at low load operating conditions, the engine is run in Pre-mixed Charge Compression Ignition (PCCI) mode, whereas at high load conventional CI combustion is applied. This study was done with standard diesel fuel on a flexible multi-cylinder heavy-duty test platform. This platform is based on a 12.9 liter, 390 kW heavy-duty diesel engine that is equipped with a combination of a supercharger, a two-stage turbocharging system and low-pressure and high-pressure EGR circuitry. Furthermore, Variable Valve Actuation (VVA) hardware is installed to have sufficient control authority. Dedicated pistons, injector nozzles and VVA cam were selected to enable PCCI combustion for a late DI injection strategy, free of wall-wetting problems.

Manganese oxides show high catalytic activity for CO and HC oxidation without including platinum group metals (PGM). However, there are issues with both thermal stability and resistance to sulfur poisoning. We have studied perovskite-type YMnO3 (YMO) with the aim of simultaneously achieving both activity and durability. This paper describes the oxidation activity of PGM-free Ag/i-YMO, which is silver supported on improved-YMO (i-YMO). The Ag/i-YMO was obtained by the following two methods. First, Mn4+ ratio and specific surface area of YMO were increased by optimizing composition and preparation method. Second, the optimum amount of silver was supported on i-YMO. In model gas tests and engine bench tests, the Ag/i-YMO catalyst showed the same level of activity as that of the conventional Pt/?-Al2O3 (Pt = 3.0 g/L). In addition, there was no degradation with respect to either heat treatment (700°C, 90 h, air) or sulfur treatment (600°C to 200°C, total 60 h, 30 ppm SO2).

Downsizing and downspeeding are two efficient strategies to reduce vehicles CO2 emission, provided that high BMEP can be achieved at any engine speed under clean, safe, stable and efficient combustion. With a 6:1 minimum compression ratio, the MCE-5 VCRi achieves 40 bar peak BMEP at 1200 rpm with no irregular combustion. If peak BMEP is maintained below 35 bar, fuel enrichment is no longer necessary. When running at part loads, the engine operates at high compression ratios (up to 15:1) to minimize BSFC and maximize the sweet spot area on the map. Next generation MCE-5 VCRi engines will combine VCR and stoichiometric charges, highly diluted with external cooled EGR, in order to improve part loads efficiency by means of both the reduction in heat and pumping losses, and the optimization of compression-expansion ratio. This strategy, added to downsizing-donwspeeding, requires high-energy ignition systems to promote repeatable, stable, rapid and complete combustion.

Historically, the opposed-piston, two-stroke (OP2S) diesel engine set combined records for fuel efficiency and power density that have yet to be met by any other engine type. However, with modern emissions standards, wide-spread development of this engine for on-highway use stopped. At Achates Power, state-of-the-art analytical tools and engineering methods have produced an OP2S engine that, when compared to a leading medium-duty engine, has demonstrated a 21% fuel efficiency gain and engine-out emissions levels meeting U.S. EPA10 with conventional after-treatment. Among the presentation topics covered are thermodynamic efficiency, demonstrated engine results, cost and weight advantages, and overcoming two-stroke engine challenges. Presenter David Johnson, Achates Power Inc.

A conceptual project aimed at understanding the fundamental design considerations concerning the implementation of catalyst systems on outboard marine engines was carried out by Mercury Marine, with the support of the California Air Resources Board. In order to keep a reasonable project scope, only electronic fuel injected four-stroke outboards were considered. While they represent a significant portion of the total number of outboard engines sold in the United States, carbureted four-strokes and direct injected two-strokes pose their own sets of design constraints and were considered to be outside the scope of this study. Recently, three-way catalyst based exhaust emissions aftertreatment systems have been introduced into series production on sterndrive and inboard marine spark ignition engines in North America. The integration of catalyst systems on outboards is much more challenging than on these other marine propulsion alternatives.

This paper reports results of an experimental investigation performed on a commercial diesel engine supplied with fuel blends having low cetane number to attain a simultaneous reduction in NOx and smoke emissions. Blends of 20% and 40% of n-butanol in conventional diesel fuel have been tested, comparing engine performance and emissions to diesel ones. Taking advantage of the fuel blend higher resistance to auto ignition, it was possible to extend the range in which a premixed combustion is achieved. This allowed to match the goal of a significant reduction in emissions without important penalties in fuel consumption. The experimental activity was carried on a turbocharged, water cooled, 4 cylinder common rail DI diesel engine. The engine equipment included an exhaust gas recirculation system controlled by an external driver, a piezo-quartz pressure transducer to detect the in-cylinder pressure signal and a current probe to acquire the energizing current to the injector.

Ford's EcoBoost GTDI engine technology (Gasoline Direct Injection, Turbo-charging and Downsizing) is being successfully implemented in the market place with the EcoBoost option accounting for significant volumes in vehicle lines as diverse as the F150 pickup truck, Edge CUV and the Lincoln MKS luxury sedan. A logical question would be what comes after GTDI? This presentation will review some of the technologies that will be required for further improvements in CO2, efficiency and performance building on the EcoBoost foundation as well as some of the challenges inherent in the new technologies and approaches. Presenter Eric W. Curtis, Ford Motor Co.

Combustion engines are typically only 20-30% efficient at part-load operating conditions, resulting in poor fuel economy on average. To address this, LiquidPiston has developed an improved thermodynamics cycle, called the High-Efficiency Hybrid Cycle (HEHC), which optimizes each process (stroke) of the engine operation, with the aim of maximizing fuel efficiency. The cycle consists of: 1) a high compression ratio; 2) constant-volume combustion, and 3) over-expansion. At a modest compression ratio of 18:1, this cycle offers an ideal thermodynamic efficiency of 74%. To embody the HEHC cycle, LiquidPiston has developed two very different rotary engine architectures ? called the ?M? and ?X? engines. These rotary engine architectures offer flexibility in executing the thermodynamics cycle, and also result in a very compact package. In this talk, I will present recent results in the development of the LiquidPiston engines. The company is currently testing 20 and 40 HP versions of the ?M?

In this presentation, we will explain how the traditional Miller Cycle - which has its limitations in the traditional four-stroke, Otto Cycle engine provides new opportunities for greater fuel efficiency gains and engine downsizing when incorporated in a split-cycle combustion process. Results will also be shared from studies showing how these implementations can provide both significant drops in fuel consumption and increases in power when incorporated into some of today's most economic vehicles. Presenter Stephen Scuderi, Scuderi Group LLC

Gasoline engines continue to suffer from significant pumping losses despite decades of effort focused on reducing throttling. Honeywell Turbo has developed a throttle with an integrated turbine/generator that generates electricity by recovering pumping work. This energy offsets power normally provided by the crank driven alternator, thereby saving fuel. It integrates well with modern electrical systems which employ smart charging and idle stop strategies. The ThrottleCharger provides fuel economy benefits up to 5% over federal test cycles and in real world conditions. Presenter Mike Guidry, Honeywell Int'l (Turbo Technologies)

Future fuel economy targets represent a significant challenge to the automotive industry. While a range of technologies are in research and development to address this challenge, they all bring additional cost and complexity to future products. The most cost effective solutions are likely to be combinations of technologies that in isolation might have limited advantages but in a systems approach can offer complementary benefits. This presentation describes work carried out at Ricardo to explore Intelligent Electrification and the use of Stratified Charge Lean Combustion in a spark ignition engine. This includes a next generation Spray Guided Direct Injection SI engine combustion system operating robustly with highly stratified dilute mixtures and capable of close to 40% thermal efficiency with very low engine-out NOx emissions.

Four-way, integrated, diesel emission control systems that combine selective catalytic reduction for NOx control with a continuously regenerating trap to remove diesel particulate matter were evaluated under real-world, on-road conditions. Tests were conducted using a semi-tractor with an emissions year 2000, 6-cylinder, 12 L, Volvo engine rated at 287 kW at 1800 rpm and 1964 N-m. The emission control system was certified for retrofit application on-highway trucks, model years 1994 through 2002, with 4-stroke, 186-373 kW (250-500 hp) heavy-duty diesel engines without exhaust gas recirculation. The evaluations were unique because the mobile laboratory platform enabled evaluation under real-world exhaust plume dilution conditions as opposed to laboratory dilution conditions. Real-time plume measurements for NOx, particle number concentration and size distribution were made and emission control performance was evaluated on-road.

Turbulent Jet Ignition is an advanced spark initiated pre-chamber combustion system for otherwise standard spark ignition engines. Combustion in the main chamber is initiated by jets of partially combusted (reacting) pre-chamber products which provide a high energy ignition source. The resultant widely distributed ignition sites allow relatively small flame travel distances enabling short combustion durations and high burn rates. This presentation outlines development of this combustion concept in a modern normally aspirated PFI production engine. Experimental results have highlighted high thermal efficiency (42.8%), significant fuel economy improvement (>20%), low engine out NOx (<10 ppm), knock limit extension, high load capability (>13 bar IMEPn) and high speed operation (5500 rev/min). Presenter William P Attard, MAHLE Powertrain LLC

The combination of advanced combustion with advanced selective catalytic reduction (SCR) catalyst formulations was studied in the work presented here to determine the impact of the unique hydrocarbon (HC) emissions from premixed charge compression ignition (PCCI) combustion on SCR performance. Catalyst core samples cut from full size commercial Fe- and Cu-zeolite SCR catalysts were exposed to a slipstream of raw engine exhaust from a 1.9-liter 4-cylinder diesel engine operating in conventional and PCCI combustion modes. The zeolites which form the basis of these catalysts are different with the Cu-based catalyst made on a chabazite zeolite which las smaller pore structures relative to the Fe-based catalyst. Subsequent to exposure, bench flow reactor characterization of performance and hydrocarbon release and oxidation enabled evaluation of overall impacts from the engine exhaust.