Viewing 1 to 30 of 49
Journal Article
Walter F. Piock, Peter Weyand, Edgard Wolf, Volker Heise
The success of stratified combustion is strongly determined by the injection and ignition system used. A large temporal and spatial variation of the main parameters - mixture composition and charge motion - in the vicinity of the spark location are driving the demands for significantly improved ignition systems. Besides the requirements for conventional homogeneous combustion systems higher ignition energy and breakdown voltage capability is needed. The spark location or spark plug gap itself has to be open and well accessible for the mixture to allow a successful flame kernel formation and growth into the stratified mixture regime, while being insensitive to potential interaction with liquid fuel droplets or even fuel film. For this purpose several different ignition concepts are currently being developed. The present article will give an ignition system overview for stratified combustion within Delphi Powertrain Systems.
Technical Paper
Marek Tatur, Martin Laermann, Erik Koehler, Dean Tomazic, Taylor Holland, David Robinson, Jeffrey Dowell, Kenneth Price
In order to allow continued production of the AM General Optimizer 6500 during MY 2007 through 2010 this IDI engine (Indirect Injection - swirl chamber) requires sophisticated aftertreatment controls while maintaining its fuel economy and durability. The main purpose of the development program was to retain the relatively inexpensive and simple base engine with distributor pump and waste-gated turbocharger, while adding hardware and software components that allow achievement of the phase-in emission standards for 2007 through 2010. The aftertreatment system consists of Diesel Oxidation Catalyst (DOC), NOx Adsorber Catalyst (or DeNOx Trap - DNT) and Diesel Particle Filter (DPF). In addition to the base hardware, an intake air throttle valve and an in-exhaust fuel injector were installed. The presented work will document the development process for a 2004 certified 6.5 l IDI heavy-duty diesel engine to comply with the 2007 heavy-duty emission standards.
Technical Paper
Yong Yi, Christopher M. DeMinco
The purpose of the present paper is to develop an engine simulation tool in a commercial CFD code to study the spray and mixing process that can be used to access the performance of a Gasoline Direct Injection (GDI) engine. The ignition, combustion and pollutant formation are strongly dependent on the quality of the fuel-air mixture. The fuel is injected directly into the combustion chamber by high-pressure fuel injector. The fuel atomization and evaporation process takes place due to the interaction of the small fuel particles generated by the injector and the in-cylinder air motion. Experimental study on the spray and mixing process is difficult and expensive, which has been recognized as a major obstacle towards the optimization of the combustion chamber geometry, engine components and the injection strategies.
Technical Paper
Douglas Ball, John Nunan, Patrick Blosser, Jennifer Wilson, George Mitchell, Stuart Davis, Mike Zammit
A new family of automotive three-way conversion (TWC) catalyst technologies has been developed using a Precision Metal Addition (PMA) process. Precious metal (PGM) fixation onto the support occurs during the PMA step when the PGM is added to the slurry immediately prior to application to the monolith substrate. PMA slurries can be prepared with high precision and the slurry manufacturing process is greatly simplified. Further, it has been found that with the use of new generation washcoat (WC) materials, the same WC composition can be used for all three PGMs - Pt, Pd & Rh. Negative interactions between Pd and Rh in the same WC layer do not occur, providing advantages over older technologies. Thus, new WC compositions coupled with the PMA process offers precious metal flexibility. This FlexMetal family of catalyst technologies includes single layer Pd-only, Pd/Rh and Pt/Rh and dual layer bi-metal Pd/Rh and Pt/Rh and tri-metal Pt/Pd/Rh.
Technical Paper
Mahmoud Ghodbane, James A. Baker, Prasad S. Kadle
Worldwide scrutiny of the global warming impact of R-134a has presented the automotive industry with a pressing challenge to search for suitable alternative refrigerant(s). HFC-152a, referred to as R-152a in the air conditioning and refrigeration industry, is touted as an alternative [1, 2] to R-134a because of its lower global warming potential (GWP). R-152a is more environmentally benign than R-134a with GWP of 120 versus 1300. This paper is a follow up to the work on the potential applications of R-152a presented at the 2003 Vehicle Thermal Management Systems Conference (VTMS6) [3]. It documents continuing progress in applying R-152a to vehicle climate control systems. The paper compares R-152a cooling performance and energy performance to comparable R-134a system designs, including direct and indirect expansion systems. Also discussed are efforts to provide safe system operation with R-152a refrigerant.
Technical Paper
V. Nagaraju, N. Henein, A. Quader, M. Wu, Walter Bryzik
The focus of this study is to determine the effect of using B-20 (a blend of 20% soybean methyl ester biodiesel and 80% ultra low sulfur diesel fuel) on the combustion process, performance and exhaust emissions in a High Speed Direct Injection (HSDI) diesel engine equipped with a common rail injection system. The engine was operated under simulated turbocharged conditions with 3-bar indicated mean effective pressure and 1500 rpm engine speed. The experiments covered a wide range of injection pressures and EGR rates. The rate of heat release trace has been analyzed in details to determine the effect of the properties of biodiesel on auto ignition and combustion processes and their impact on engine out emissions. The results and the conclusions are supported by a statistical analysis of data that provides a quantitative significance of the effects of the two fuels on engine out emissions.
Technical Paper
Marek Tatur, Erik Koehler, Martin Laermann, Dean Tomazic, Taylor Holland, David Robinson, Jeffrey Dowell, Kenneth Price
The implementation and development efforts of lean NOx trap catalysts for heavy-duty applications decreased a number of years ago. Most heavy-duty engine manufacturers realized that the system complexity as well as the durability of such a system does not allow large volume production without significant risk. The current consensus of the heavy-duty community is that for 2010 the SCR system will be the prime path to meet the 0.2 g/bHPhr NOx emission standard, although this is subject to adequate infrastructure investment and progress. As a low volume manufacturer, in order to comply with the 2007 heavy-duty phase-in emission standards, General Engine Products (a subsidiary of AM General LLC) integrated a NOx adsorber system on the Optimizer 6500 engine. This engine features split combustion chamber design, rotary fuel injection pump and operates with EGR.
Technical Paper
In Kwang Yoo, Devesh Upadhyay, Giorgio Rizzoni
Carbon canisters have been adapted for automobile use since the early 1970s to control evaporative emissions. Stringent emission regulations and the requirement for an enhanced evaporative emissions test procedure, make this an important issue. The air and evaporative fuel from the carbon canister therefore need important consideration with respect to air to fuel ratio (AFR) control and idle by-pass air control. Although a few complex models of the activated carbon canister have been developed, a control-oriented, simplistic carbon canister model needs to be developed. This paper explores the control-oriented modeling of a canister purge air system along with the on-line estimation of evaporative fuel loading of the activated carbon. An attempt was made at providing an analytical expression for the evaporative fuel and air entering the intake manifold.
Technical Paper
In Kwang Yoo, Devesh Upadhyay, Yong Wha Kim, Giorgio Rizzoni
Due to the stringent emission regulations, On-Board Diagnostics II (OBD II) and the requirement of enhanced evaporative emissions test procedure, an aggressive canister purge control strategy is required for automotive vehicles. The enhanced evaporative emissions test procedure has forced car manufacturer to purge the carbon canister in the vehicle idle condition so that production vehicles meet the SHED and hot soak test requirements. This not only worsens the idle speed quality but also tends to increase exhaust emission levels. Using analytical models of evaporative air and fuel, feed-forward control strategy for both idle by-pass air and air to fuel ratio can be improved. This paper demonstrates an application of evaporative system modeling to the idle air and air to fuel ratio control.
Technical Paper
Milton D. Johnson, Robert W. McCabe, Carolyn P. Hubbard, Michael J. Riley, Charles W. Kirby, Douglas J. Ball, Glenn Tripp, Thomas F. McDonnell, William Y. Lam
The relationship between engine oil formulations and catalyst performance was investigated by comparatively testing five engine oils. In addition to one baseline production oil with a calcium plus magnesium detergent system, the remaining four oils were specifically formulated with different additive combinations including: one worst case with no detergent and production level zinc dialkyldithiophosphate (ZDTP), one with calcium-only detergent and two best cases with zero phosphorus. Emissions performance, phosphorus loss from the engine oil, phosphorus-capture on the catalyst and engine wear were evaluated after accumulating 100,000 miles of taxi service in twenty vehicles. The intent of this comparative study was to identify relative trends.
Technical Paper
James A. Baker, Mahmoud Ghodbane, Lawrence P. Scherer, Prasad S. Kadle, William R. Hill, Stephen O. Andersen
In recent years, climate protection has become as important as ozone layer protection was in the late 1980's and early 1990s. Concerns about global warming and climate change have culminated in the Kyoto Protocol, a treaty requiring its signatories to limit their total emission of greenhouse gases to pre-1990 levels by 2008. The inclusion of hydrofluorocarbons (HFCs) as one of the controlled substances in the Kyoto Protocol has increased global scrutiny of the global warming impact of HFC-134a (called R-134a when used as a refrigerant), the current mobile air conditioning refrigerant. Industry's first response was to begin improving current R-134a systems to reduce leakage, reduce charge, and increase system energy efficiency, which in turn reduces tailpipe CO2 emissions. An additional option would be to replace the current R-134a with a refrigerant of lower global warming impact. This paper documents the use of another HFC, R-152a, in a mobile A/C system.
Technical Paper
Lawrence P. Scherer, Mahmoud Ghodbane, James A. Baker, Prasad S. Kadle
As automotive power-train systems become more efficient, less waste heat is available for vehicle passenger cabin warming. As a result, alternative heating technologies are being investigated to alleviate this shortcoming. One alternative is to operate the existing A/C system in reverse (heat pump mode), thus providing supplemental heat. Recently, the environmental impact of refrigerant emissions has come under global scrutiny. The concern is their potential for global warming. Thus, the environmental characteristic of merit that makes for a more benign refrigerant in terms of emissions is lower Global Warming Potential (GWP). R-152a is a more environmentally benign refrigerant compared to R-134a with a GWP of 120 vs. 1,300 [1] and [2]. Both refrigerants are hydro-fluorocarbons - HFCs - (contain no chlorine) and hence, have zero ozone depletion potential. An environmentally benign refrigerant touted as a potential replacement for R-134a, is CO2.
Low temperature combustion (LTC) remains an area of high interest with extensive research, even though many challenges must still be overcome before LTC sees commercial acceptance.
With continuing pressure to increase fuel economy with ever lower emissions, industry specialists and researchers presented key findings in new, combustion schemes and research.
Using quartz and sapphire components, high-powered lasers and scientific cameras researchers are able to see inside an operating engine—and that vision is proving to be a valuable aid for finding ways to reduce diesel emissions. Could this research hold the key to maximizing the benefits of low-temperature diesel combustion without incurring the typical emissions penalty?
Delphi is developing an SCR dosing system scheduled for production in 2014 and will also introduce an ammonia sensor in 2012 to control the level of ammonia present in the exhaust as a consequence of using urea dosing in the SCR systems.
U.S. EPA five-cycle tests for fuel economy encourage stop-start systems, but loss of air-conditioning operation may be unacceptable.
Idle-stop may add to city fuel economy and is eligible for 2.9 g/mi carbon credits, so it is starting to appear as a U.S. option. Need for A/C operation leads to evaluation of evaporators with thermal storage in waxes. Delphi promises U.S. OE installation for 2015, following low-volume Behr system in European BMW 7 Series.
Delphi designed the new solenoid-type Multec injectors to deliver piezo-type performance. The Multi-Charge Ignition is aimed at spray-guided stratified-charge combustion strategies as well as HCCI development.
Production of Delphi’s Direct Acting Diesel Common Rail (DADCR) system has started, following a five-year development program in France, Luxembourg, and the UK. The system incorporates direct-acting piezo injectors—claimed by the company as a "world first" that can operate at pressures up to 2000 bar (29 ksi) and will help meet Euro 6 emissions standards.
Lower emissions and component mass are on the front burner at Delphi's new advanced diesel technology center in Luxembourg.
Speaking at the IAA Frankfurt Show, Christian Schäfer, Global Director of Advanced Electrical and Electronic Architectures at Delphi told Automotive Engineering that there are several drivers for the technology that were not present 15 years ago.
The four-year, $15 million development program with UW-Madison and Wayne State University aims to achieve diesel levels of efficiency and torque, with lower emissions and cost—in an advanced gasoline-fueled engine.
Allison Transmission Inc. has entered into a long-term business agreement with Delphi Automotive Systems, LLC, with Delphi supplying to Allison hybrid-drive system components and energy storage systems.
Delpi's new-generation gasoline direct-injection compression-ignition (GDCI) fueling system brings a new level of thermal efficiency for gasoline engines and is said to conquer earlier emissions challenges.
The supplier revealed its medium- and heavy-duty diesel fuel injection systems, designed to meet the needs of engine manufacturers for Euro 6, U.S. EPA 2010, Japan PNLTR, and future emissions requirements, at the recent IAA Commercial Vehicles show in Hannover, Germany.
To downsize or not to downsize engines? That’s the question facing all OEMs. In an initial move to be more environmentally responsible, for many downsizing seemed to be thoroughly sensible. But is it? Executives have their say.
The two-year test program aims to demonstrate Ricardo's new spark-ignition flex-fuel engine technology, designed to provide diesel-like attributes with improved package efficiency and reduced cost.
After 2020 the number of ‘new’ engine family introductions will decline, as industry switches its investment over to e-propulsion. Suppliers need to be prepared for this shift.
Delphi launches a comprehensive diesel particulate filter (DPF) program that includes a retrofit aftertreatment system and cleaning process.
Viewing 1 to 30 of 49


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