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A follow-up to the 1989 Society of Automotive Engineers (SAE) Methanol Marathon called the Methanol Challenge was held in April 1990. One of a series of engineering student competitions using alternative fuels organized and conducted by the Center for Transportation Research at Argonne National Laboratory, the Methanol Challenge pushed the technology for dedicated M85 (85% methanol, 15% hydrocarbon fuel) methanol passenger cars to new levels. The event included complete federal exhaust emissions, cold-start and driveability, performance, and fuel economy testing. Twelve teams of student engineers from the United States and Canada competed in the Challenge using Chevrolet Corsicas donated by General Motors (GM) to the schools. The winning car, from the University of Tennessee, simultaneously demonstrated extremely low emissions, dramatically increased performance, and significantly improved fuel economy.

Vehicle operation during cold-start powertrain conditions can have a significant impact on drivability, fuel economy and tailpipe emissions in modern passenger vehicles. As efforts continue to maximize fuel economy in passenger vehicles, considerable engineering resources are being spent in order to reduce the consumption penalties incurred shortly after engine start and during powertrain warmup while maintaining suitably low levels of tailpipe emissions. Engine downsizing, advanced transmissions and hybrid-electric architecture can each have an appreciable effect on cold-start strategy and its impact on fuel economy. This work seeks to explore the cold-start strategy of several passenger vehicles with different powertrain architectures and to understand the resulting fuel economy impact relative to warm powertrain operation. To this end, four vehicles were chosen with different powertrain architectures.

Two-phase flow experiments were performed with air/water mixtures in a small rectangular channel measuring 9.52 x 1.59 mm (aspect ratio equal to 6), for application to compact heat exchangers. Pressure drop and flow pattern definition data were obtained over a large range of mass qualities (0.0002 to 1) and, in the case of flow pattern data, a large range of mass fluxes (50 to 2,000 kg/m2s). A flow pattern map, based on visual observations and photographs of the flow patterns, is presented and compared with a map developed for a rectangular channel of the same aspect ratio but with dimensions twice those of the test channel, and with a map developed for a circular tube with the same hydraulic diameter of 3 mm. Pressure drop data are presented as a function of both mass quality and Martinelli parameter and are compared with state-of-the-art correlations and a modified Chisholm correlation.

A new method is proposed for controlling the temperature of high-temperature batteries namely, varying the hydrogen pressure inside of multifoil insulation by varying the temperature of a reversible hydrogen getter. Calculations showed that the rate of heat loss through 1.5 cm of multifoil insulation between a hot-side temperature of 425°C and a cold-side temperature of 25°C could be varied between 17.6 W/m2 and 7,000 W/m2. This change in heat transfer rate can be achieved by varying the hydrogen pressure between 1.0 Pa and 1000 Pa, which can be done with an available hydrogen gettering alloy operating in the range of 50°C to 250°C. This approach to battery cooling requires cylindrical insulating jackets, which are best suited for bipolar batteries having round cells approximately 10 to 18 cm in diameter.

A production spark ignition engine powered vehicle (3.1-L Chevrolet Lumina, model year 1990) was tested with oxygen-enriched intake air containing 25 and 28% oxygen by volume to determine if (1) the vehicle would run without difficulties and (2) there would be emissions benefits. Standard Federal Test Procedure (FTP) emissions test cycles were run satisfactorily without vehicle performance anomalies. The results of catalytic converter-out (engine with a three-way catalytic converter in place) emissions showed that both carbon monoxide and hydrocarbons were reduced significantly in all three phases of the emissions test cycle, compared with normal air (21 % oxygen). Carbon monoxide emissions from the engine (with the three-way catalytic converter removed) were significantly reduced in the cold-phase of the test cycle. The catalytic converter also had an improved carbon monoxide conversion efficiency under the oxygen-enriched air conditions.

A hybrid bus powered by a diesel engine and a battery pack has been analyzed over an idealized bus-driving cycle in Chicago. Three hybrid configurations, two parallel and one series, have been evaluated. The results indicate that the fuel economy of a hybrid bus, taking into account the regenerative braking, is comparable with that of a conventional diesel bus. Life-cycle costs are slightly higher because of the added weight and cost of the battery.

This paper explores the impact of U.S. emission controls and fuel economy improvements on the global warming potential (GWP) of new light-duty vehicles. Fuel economy improvements have reduced the GWP of both passenger cars and light-duty trucks by lowering the per mile emissions of carbon dioxide (CO2). Further GWP reductions have been achieved by emission standards for criteria pollutants: carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). The GWP of a criteria pollutant was calculated by multiplying the emission rate by a relative global warming factor to obtain a CO2 equivalent emission rate. Both CO2 and criteria pollutant emission rates per vehicle have decreased substantially for new light-duty vehicles over the period from 1968 to 1991. Over that period, the GWP from CO2 was reduced by almost 50% in new vehicles by improving fuel economy.

Advanced heat-pump cycles are being investigated for various applications. However, the working media and associated thermal design aspects require new concepts for maintaining high thermal effectiveness and phase equilibrium for achieving maximum possible thermodynamic advantages. In the present study, the heat- and mass-transfer processes in two heat-pump systems -- those based on absorption processes, and those using refrigerant mixtures -- are analyzed. The major technical barriers for achieving the ideal performance predicted by thermodynamic analysis are identified. The analysis provides general guidelines for the development of heat- and mass-transfer equipment for advanced heat-pump systems.

The U.S. Department of Energy sponsored several student engineering competitions in 1993 that provided useful information on electric and hybrid electric vehicles. The electrical energy usage from these competitions has been recorded with a custom-built digital meter installed in every vehicle and used under controlled conditions. When combined with other factors, such as vehicle mass, speed, distance traveled, battery type, and type of components, this information provides useful insight into the performance characteristics of electrics and hybrids. All the vehicles tested were either electric vehicles or hybrid vehicles in electric-only mode, and had an average energy economy of 7.0 km/kWh. Based on the performance of the “ground-up” hybrid electric vehicles in the 1993 Hybrid Electric Vehicle Challenge, data revealed a 1 km/kWh energy economy benefit for every 133 kg decrease in vehicle mass.

The 1994 Hybrid Electric Vehicle Challenge provided the backdrop for collecting data and developing testing procedures for hybrid electric vehicle technology available at colleges and universities across North America. The data collected at the competition was analyzed using the HEV definitions from the draft SAE J1711 guidelines. The energy economy, percentage of electrical to total energy used, and acceleration performance was analyzed for any correlation between the over-the-road data and the commuter-sustaining, commuter-depleting, and reserve-sustaining hybrid vehicles. The analysis did not provide any direct correlation between over-the-road data and the three hybrid types. The analysis did show that the vehicle configurations provide the best information on vehicle performance. It was also clear that a comprehensive data analysis system along with a well-defined testing procedure would allow for a more complete analysis of the data.

From June 12-20, 1994, an engineering design competition called the 1994 Hybrid Electric Vehicle (HEV) Challenge was held in Southfield, Michigan. This collegiate-level competition, which involved 36 colleges and universities from across North America, challenged the teams to build a superior HEV. One component of this comprehensive competition was the emissions event. Special HEV testing procedures were developed for the competition to find vehicle emissions and correct for battery state-of-charge while fitting into event time constraints. Although there were some problems with a newly-developed data acquisition system, we were able to get a full profile of the best performing vehicles as well as other vehicles that represent typical levels of performance from the rest of the field. This paper will explain the novel test procedures, present the emissions and fuel economy results, and provide analysis of second-by-second data for several vehicles.

As a life-cycle analysis tool, MARVEL has been developed for the evaluation of hybrid/electric vehicle systems. It can identify the optimal combination of battery and heat engine characteristics for different vehicle types and performance requirements, on the basis of either life-cycle cost or fuel efficiency. Battery models that allow trade-offs between specific power and specific energy, between cycle life and depth of discharge, between peak power and depth of discharge, and between other parameters, are included in the software. A parallel hybrid configuration, using an internal combustion engine and a battery as the power sources, can be simulated with a user-specified energy management strategy. The PC-based software package can also be used for cost or fuel efficiency comparisons among conventional, electric, and hybrid vehicles.

The life-cycle energy and fuel-use impacts of U.S.-produced aluminum-intensive passenger cars and passenger trucks are assessed. The energy analysis includes vehicle fuel consumption, material production energy, and recycling energy. A model that simulates market dynamics was used to project aluminum-intensive vehicle market shares and national energy savings potential for the period between 2005 and 2030. We conclude that there is a net energy savings with the use of aluminum-intensive vehicles. Manufacturing costs must be reduced to achieve significant market penetration of aluminum-intensive vehicles. The petroleum energy saved from improved fuel efficiency offsets the additional energy needed to manufacture aluminum compared to steel. The energy needed to make aluminum can be reduced further if wrought aluminum is recycled back to wrought aluminum. We find that oil use is displaced by additional use of natural gas and nonfossil energy, but use of coal is lower.

Oxygen-enriched combustion is a proven, seriously considered technique to reduce exhaust hydrocarbons (HC) and carbon monoxide (CO) emissions from automotive gasoline engines. This paper presents the cold-phase emissions reduction results of using oxygen-enriched intake air containing about 23% and 25% oxygen (by volume) in a vehicle powered by a spark-ignition (SI) engine. Both engine-out and converter-out emissions data were collected by following the standard federal test procedure (FTP). Converter-out emissions data were also obtained employing the U.S. Environmental Protection Agency's (EPA's) “Off-Cycle” test. Test results indicate that the engine-out CO emissions during the cold phase (bag 1) were reduced by about 46 and 50%, and HC by about 33 and 43%, using nominal 23 and 25% oxygen enriched air compared to ambient air (21% oxygen by volume), respectively. However, the corresponding oxides of nitrogen (NOx) emissions were increased by about 56 and 79%, respectively.

The objective of this paper is to analyze and summarize the performance results and the technology used in the 1995 Hybrid Electric Vehicle (HEV) Challenge. Government and industry are exploring hybrid electric vehicle technology to significantly improve fuel economy and reduce emissions of the vehicles without sacrificing performance. This last in a three-year series of HEV competitions provided the testing grounds to evaluate the different approaches of 29 universities and colleges constructing HEVs. These HEVs competed in an array of events, including: acceleration, emissions testing, consumer acceptance, range, vehicle handling, HVAC testing, fuel economy, and engineering design. The teams also documented the attributes of their vehicles in the technical reports. The strategies and approaches to HEV design are analyzed on the basis of the data from each of the events. The overall performance for promising HEV approaches is also examined.

In the 1995 HEV Challenge competition, 17 prototype Hybrid Electric Vehicles (HEVs) were tested by using special HEV test procedures. The contribution of the batteries during the test, as measured by changes in battery state-of-charge (SOC), were accounted for by applying SOC corrections to the test data acquired from the results of the HEV test. The details of SOC corrections are described and two different HEV test methods are explained. The results of the HEV test methods are explained. The results of the HEV tests and the effects on the test outcome of varying HEV designs and control strategies are examined. Although many teams had technical problems with their vehicles, a few vehicles demonstrated high fuel economy and low emissions. One vehicle had emissions lower than California's ultra-low emission vehicle (ULEV) emissions rates, and two vehicles demonstrated higher fuel economy and better acceleration than their stock counterparts.

This paper presents the results of emission tests of a flexible fuel vehicle (FFV) powered by an SI engine, fueled by M85, and supplied with oxygen-enriched intake air containing nominal 21%, 23%, and 25% oxygen (by volume). Emission data were collected by following the standard federal test procedure (FTP) and U.S. Environmental Protection Agency's (EPA's) “off-cycle” test EPA-REP05. Engine-out total hydrocarbons (THCs) and unburned methanol were considerably reduced in the entire FTP cycle when the oxygen content of the intake air was either 23% or 25%. However, CO emissions did not vary appreciably, and NOx emissions were higher. Formaldehyde emissions were reduced by about 53% in bag 1, 84% in bag 2, and 59% in bag 3 of the FTP cycle when 25% oxygen-enriched intake air was used.

The U.S. Department of Energy, through Argonne National Laboratory, and in cooperation with Natural Resources-Canada and Chrysler Canada, sponsored and organized the 1996 Propane Vehicle Challenge (PVC). For this competition, 13 university teams from North America each received a stock Chrysler minivan to be converted to dedicated propane operation while maintaining maximum production feasibility. The converted vehicles were tested for performance (driveability, cold- and hot-start, acceleration, range, and fuel economy) and exhaust emissions. Of the 13 entries for the 1996 PVC, 10 completed all of the events scheduled, including the emissions test. The schools used a variety of fuel-management, fuel-phase and engine-control strategies, but their strategies can be summarized as three main types: liquid fuel-injection, gaseous fuel-injection, and gaseous carburetor. The converted vehicles performed similarly to the gasoline minivan.

There has been a recent trend toward the use of lifecycle analysis (LCA) as a decision-making tool for the automotive industry. However, the different practitioners' methods and assumptions vary widely, as do the interpretations put on the results. The lack of uniformity has been addressed by such groups as the Society of Environmental Toxicology and Chemistry (SETAC) and the International Organization for Standardization (ISO), but standardization of methodology assures neither meaningful results nor appropriate use of the results. This paper examines the types of analysis that are possible for automobiles, explains possible pitfalls to be avoided, and suggests ways that LCA can be used as part of a rational decision-making procedure. The key to performing a useful analysis is identification of the factors that will actually be used in making the decision. It makes no sense to analyze system energy use in detail if direct financial cost is to be the decision criterion.

The effects of fuel properties on the emissions of a production vehicle with a gasoline direct injection engine operating over the Federal Test Procedure (FTP) cycle were investigated. The vehicle used was a 1998 Toyota Corona passenger car with a direct injection spark ignition (DISI) engine. Engine-out and tailpipe FTP emissions for six fuels and a California Phase 2 RFG reference fuel are presented. Four of the test fuels were blended from refinery components to meet specified distillation profiles. The remaining test fuels were iso-octane and toluene, an iso-alkane and an aromatic with essentially the same boiling point (at atmospheric pressure) that is near the T50 point for the blended fuels. Statistically significant effects, at the 95% confidence level, of the fuels on tailpipe emissions were found. Correlations were sought between the properties of the five blends and the Emissions Indices for engine-out hydrocarbons and NOx and for tailpipe particulates.