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Historically, heavy-duty diesel (HDD) engine designs have evolved along the path of increased power output, improved fuel efficiency and reduced exhaust gas emissions, driven both by regulatory and market requirements. The various technologies employed to achieve this evolution have resulted in ever-increasing engine operating cylinder pressures, higher than for any other class of internal combustion engine. Traditional HDD engine design architecture limits peak cylinder pressure (PCP) to about 200 bar (2900 psi). HDD PCP had steadily increased from the early 1970's until the mid 2000's, at which point the structural limit was reached using traditional methods and materials. Specific power output reversed its historical trend and fell at this time as a result of technologies employed to satisfy new emissions requirements, most notably exhaust gas recirculation (EGR).

The spark ignition (SI) engine has been known to exhibit several different abnormal combustion phenomena, such as knock or pre-ignition, which have been addressed with improved engine design or control schemes. However, in highly boosted SI engines, Low-Speed Pre-Ignition (LSPI), a pre-ignition event typically followed by heavy knock, has developed into a topic of major interest due to its potential for engine damage. Previous experiments associated increases in hydrocarbon emissions with the blowdown event of an LSPI cycle [1]. Also, the same experiments showed that there was a dependency of the LSPI activity on fuel and/or lubricant compositions [1]. Based on these findings it was hypothesized that accumulated hydrocarbons play a role in LSPI and are consumed during LSPI events. A potential source for accumulated HC is the top land piston crevice.

Experiments were performed on a 2.4L boosted, MPI gasoline engine, equipped with a low-pressure loop (LPL) cooled EGR system and an advanced ignition system, using fuels with varying anti-knock indices. The fuels were blends of 87, 93 and 105 Anti-Knock Index (AKI) gasoline. Ignition timing and EGR sweeps were performed at various loads to determine the tradeoff between EGR level and fuel octane rating. The resulting engine data was analyzed to establish the relationship between the octane requirement and the level of cooled EGR used in a given application. In addition, the combustion difference between fuels was examined to determine the effect that fuel reactivity, in the form of anti-knock index (AKI), has on EGR tolerance and burn rate. The results indicate that the improvement in effective AKI of the fuel from using EGR is constant across commercial grade gasolines at about 0.5 ON per % EGR.

This paper describes advances in variable speed supercharging, including benefits for both fuel economy and low speed torque improvement. This work is an extension of the work described in SAE Paper 2012-01-0704 [8]. Using test stand data and state-of-the-art vehicle simulation software, a NuVinci continuously variable planetary (CVP) transmission driving an Eaton R410 supercharger on a 2.2 liter diesel was compared to the same base engine/vehicle with a turbocharger to calculate vehicle fuel economy. The diesel engine was tuned for Tier 2 Bin 5 emissions. Results are presented using several standard drive cycles. A Ford Mustang equipped with a 4.6 liter SI engine and prototype variable speed supercharger has also been constructed and tested, showing low speed torque increases of up to 30%. Dynamometer test results from this effort are presented. The combined results illustrate the promise of variable speed supercharging as a viable option for the next generation of engines.

The use of fuel additives is one possible approach to reduce wear and corrosion in methanol fueled automobile engines. One hundred and six compounds added to M100 fuel in modest concentrations (1%) were tested in a Ball on Cylinder Machine (BOCM) for their ability to improve lubricity. The most promising candidates were then tested in an engine using a modified ASTM Sequence V-D wear screening test. Additive performance was measured by comparing the buildup of wear metals in the oil to that obtained from an engine fueled with neat M100. The BOCM method of evaluating the additive candidates proved inadequate in predicting abrasive engine wear under the test conditions utilized for this research program.

Impending emissions regulations for diesel engines, specifically exhaust particulate emissions have caused engine manufacturers to once again examine the potential of alternative fuels. Much interest has centered around compressed natural gas (CNG) due to its potential for low particulate and NOx emissions. Natural gas engine development projects have tended toward the use of current gasoline engine technology (stoichiometric mixtures, closed-loop fuel control, exhaust catalysts) or have applied the results of previous research in lean-burn gasoline engines (high-turbulence combustion chambers). These technologies may be inappropriate for foreseeable emissions targets in heavy-duty natural gas engines.

There is growing interest in additive manufacturing technologies for prototype if not serial production of complex internal combustion engine components such as cylinder heads and pistons. In support of this general interest the authors undertook an experimental bench test to evaluate opportunities for cooling jacket improvement through geometries made achievable with additive manufacturing. A bench test rig was constructed using electrical heating elements and careful measurement to quantify the impact of various designs in terms of heat flux rate and convective heat transfer coefficients. Five designs were compared to a baseline - a castable rectangular passage. With each design the heat transfer coefficients and heat flux rates were measured at varying heat inputs, flow rates and pressure drops. Four of the five alternative geometries outperformed the baseline case by significant margins.

The automotive industry is polarized between external pressures for ‘zero’ emission battery electric vehicles (BEV) and the ability to manufacture them economically and with minimal environmental impact. Most predictions of future BEV market share suggest that the internal combustion engine (ICE) has an important role to play in personal transportation for the next several decades. That engine will very likely be part of a hybrid architecture. Accepting that the engine will be part of a hybrid powertrain permits new design rules and strategies for the ICE. A major change of the engine could be to reduce BMEP, power density and/or engine speed requirements as performance demand will be supplemented by electric machines. This study focuses on simple changes to the ICE to increase thermal efficiency assuming supplemental electric energy.

The Scuderi internal combustion engine is characterized by a split cycle that divides the four strokes of a conventional combustion cycle over two paired cylinders, one intake/compression cylinder and one power/exhaust cylinder, connected by a crossover port. This split cycle also has an additional high pressure “crossover” gas transfer phase versus the conventional 4-stroke cycle, during which the charge air is moved from the first to the second cylinder. The intake/compression, power/exhaust and crossover events are repeated every revolution, i.e. over two cycles, with a small phase angle between the two cylinders. The separate cylinders enable opportunities for improved combustion and the possibility for pneumatic hybridization of the engine. This paper describes the technical challenges posed by the actuation of the crossover valves in the Scuderi Split Cycle research engine.

The Scuderi engine is a split cycle design that divides the four strokes of a conventional combustion cycle over two paired cylinders, one intake/compression cylinder and one power/exhaust cylinder, connected by a crossover port. This configuration provides potential benefits to the combustion process, as well as presenting some challenges. It also creates the possibility for pneumatic hybridization of the engine. This paper reviews the first Scuderi split cycle research engine, giving an overview of its architecture and operation. It describes how the splitting of gas compression and combustion into two separate cylinders has been simulated and how the results were used to drive the engine architecture together with the design of the main engine systems for air handling, fuel injection, mixing and ignition. A prototype engine was designed, manufactured, and installed in a test cell. The engine was heavily instrumented and initial performance results are presented.

Increasingly stringent fuel economy and emissions regulations around the world have forced the further optimization of nearly all vehicle systems. Many technologies exist to improve fuel economy; however, only a smaller sub-set are commercially feasible due to the cost of implementation. One system that can provide a small but significant improvement in fuel economy is the lubrication system of an internal combustion engine. Benefits in fuel economy may be realized by the reduction of engine oil viscosity and the addition of friction modifying additives. In both cases, advanced engine oils allow for a reduction of engine friction. Because of differences in engine design and architecture, some engines respond more to changes in oil viscosity or friction modification than others. For example, an engine that is designed for an SAE 0W-16 oil may experience an increase in fuel economy if an SAE 0W-8 is used.

The primary focus of this investigation was to determine the hydrogen reformation, efficiency and knock mitigation benefits of methanol-fueled Dedicated EGR (D-EGR®) operation, when compared to other EGR types. A 2.0 L turbocharged port fuel injected engine was operated with internal EGR, high-pressure loop (HPL) EGR and D-EGR configurations. The internal, HPL-EGR, and D-EGR configurations were operated on neat methanol to demonstrate the relative benefit of D-EGR over other EGR types. The D-EGR configuration was also tested on high octane gasoline to highlight the differences to methanol. An additional sub-task of the work was to investigate the combustion response of these configurations. Methanol did not increase its H2 yield for a given D-EGR cylinder equivalence ratio, even though the H:C ratio of methanol is over twice typical gasoline.

Commercial vehicles are moving in the direction of improving brake thermal efficiency while also meeting future diesel emission requirements. This study is focused on improving efficiency by replacing the variable geometry turbine (VGT) turbocharger with a high-efficiency fixed geometry turbocharger. Engine-out (EO) NOX emissions are maintained by providing the required amount of exhaust gas recirculation (EGR) using a 48 V motor driven EGR pump downstream of the EGR cooler. This engine is also equipped with cylinder deactivation (CDA) hardware such that the engine can be optimized at low load operation using the combination of the high-efficiency turbocharger, EGR pump and CDA. The exhaust aftertreatment system has been shown to meet 2027 emissions using the baseline engine hardware as it includes a close coupled light-off SCR followed by a downstream SCR system.

Methods to reduce direct injected diesel engine emissions in the combustion chamber will be discussed in this paper. The following NOx emission reduction technologies will be reviewed: charge air chilling, water injection, and exhaust gas recirculation (EGR). Emphasis will be placed on the development of an EGR system and the effect of EGR on NOx and particulates. The lower limit of NOx that can be obtained using conventional diesel engine combustion will be discussed. Further reductions in NOx may require changing the combustion process from a diffusion flame to a homogeneous charge combustion system.

Alternative combustion crossing stoichiometric air fuel ratio was investigated to utilize a 4-way catalyst system with LNT (lean NOx trap). The chemical mechanism of restricting soot formation reactions with low combustion temperature was combined with the physical mechanism of reducing smoke by lowering local equivalence ratio to enable low smoke rich and near rich combustion. A new combustion chamber for spatially and timely mixture formation phasing was developed to combine the two mechanisms and allow smooth EGR changing over a wide load range. Through this investigation, rich and near rich combustion to effectively utilize a 4-way catalyst system was realized. In addition, conditions suitable for LNT sulfur regeneration were realized from light to medium load.

The goal of this project was to demonstrate a low emissions, high efficiency heavy-duty on-highway natural gas engine. The emissions targets for this project are to demonstrate US 2010 emissions standards on the 13-mode steady state test. To meet this goal, a chemically correct combustion (stoichiometric) natural gas engine with exhaust gas recirculation (EGR) and a three way catalyst (TWC) was developed. In addition, a Sturman Industries, Inc. camless Hydraulic Valve Actuation (HVA) system was used to improve efficiency. A Volvo 11 liter diesel engine was converted to operate as a stoichiometric natural gas engine. Operating a natural gas engine with stoichiometric combustion allows for the effective use of a TWC, which can simultaneously oxidize hydrocarbons and carbon monoxide and reduce NOx. High conversion efficiencies are possible through proper control of air-fuel ratio.

Forty-five cars were entered from 37 universities across the U.S. and Canada in the ninth annual Formula SAE Student Design Competition held on May 25, 26 and 27 at the University of Texas at San Antonio (UTSA). Thirty-six cars from 31 schools actually competed, but only 22 cars finished. The event included many firsts in Formula SAE. The SAE South Texas Section set a precedent by co-hosting the competition with the UTSA. The GM Sunraycer display and demonstration exhibited high technology and corporate support of Formula SAE. Total award funds (from various sponsors) exceeded those of previous events. New awards were given by new sponsors in 1989.

This paper will describe the fuel economy benefits that can be obtained when traditionally engine-driven accessories such as water pumps, oil pumps, power steering pumps, radiator cooling fans and air conditioning compressors are decoupled from the engine and are remotely driven and controlled. Simulation results for different vehicle configurations such as heavy duty trucks operated over urban and highway driving cycles and light duty vehicles such as mini vans will be presented. These results will quantify the heavy dependence of fuel economy benefits associated with different types of driving cycles.

A vehicle's gasoline fuel tank was removed and replaced with a 5,000-psig, Type-III, aluminum-lined hydrogen cylinder. High-pressure cylinders are typically installed with a thermally-activated pressure relief device (PRD) designed to safely vent the contents of the cylinder in the event of accidental exposure to fire. The objective of this research was to assess the results of a catastrophic failure in the event that a PRD were ineffective. Therefore, no PRD was installed on the vehicle to ensure cylinder failure would occur. The cylinder was pressurized and exposed to a propane bonfire in order to simulate the occurrence of a gasoline pool fire on the underside of the vehicle. Measurements included temperature and carbon monoxide concentration inside the passenger compartment of the vehicle to evaluate tenability. Measurements on the exterior of the vehicle included blast wave pressures. Documentation included standard, infrared, and high-speed video.

Radioactive tracer technology (RATT™) is an important tool for measuring real-time wear in operating engines and other mechanical systems. The use of this technology provides important wear information that is not available by other, more conventional wear measurement methods. The technology has advanced to the point where several components can be interrogated simultaneously, and new methods have extended the method to materials that are normally not amenable to radioactive tracer evaluation. In addition, sensitivity has increased so that the onset of wear can be detected long before practical with non-tracer methods. This improves the ability to measure and determine cause and effect relationships, thus providing a better understanding of wear responses to specific operating conditions and to changes in operating conditions. This paper reviews the radioactive tracer process and recent improvements that have extended its reach in both automotive and non-automotive applications.