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In late 1997 Ford Motor Company Scientific Research Laboratory started the project to design and develop a practical, low-cost hydrogen fueled internal combustion engine (H2ICE) vehicle. This type of vehicle could serve as an interim step to drive the development of the hydrogen infrastructure before the widespread use of fuel cell vehicles. This paper will discuss the design and development approach and results for a dedicated engine optimized for operation on hydrogen, the unique and custom instrumentation necessary when working with hydrogen, the engine dynamometer development program, the unique triple-redundant vehicle safety system, and the final implementation into the Ford P2000 experimental vehicle.

As part of the P2000 hydrogen fueled internal combustion engine (H2ICE) vehicle program, an engine dynamometer research project was conducted in order to systematically investigate the unique hydrogen related combustion characteristics cited in the literature. These characteristics include pre-ignition, NOx emissions formation and control, volumetric efficiency of gaseous fuel injection and related power density, thermal efficiency, and combustion control. To undertake this study, several dedicated, hydrogen-fueled spark ignition engines (compression ratios: 10, 12.5, 14.5 and 15.3:1) were designed and built. Engine dynamometer development testing was conducted at the Ford Research Laboratory and the University of California at Riverside. This engine dynamometer work also provided the mapping data and control strategy needed to develop the engine in the P2000 vehicle.

For future hydrogen fueled ground vehicle research, Ford Motor Company has installed the first hydrogen fueling station in North America with gaseous and cryogenic hydrogen and two dedicated hydrogen fueled engine laboratory dynamometer test cells. Hydrogen, as a fuel for internal combustion engines (ICE), requires unique approaches to assure safety and accuracy in an engine-testing lab because of hydrogen's molecular size, compressibility, and reactivity. Ford Scientific Research Lab has accumulated useful experiences during the P2000 hydrogen internal combustion engine and vehicle development program. This paper presents the safety measures used in the hydrogen lab, including gas leakage sensing and warning system, hydrogen flame detecting device, cell fresh air ventilation conventions, and hydrogen fueling and purging system.

The first known, North American OEM vehicle powered exclusively by a hydrogen fueled internal combustion engine (H2ICE) has been developed and tested. This production viable, low cost, low emission vehicle is viewed as a short term driver for the hydrogen fueling infrastructure ultimately required for fuel cell vehicles. This vehicle features a highly optimized hydrogen IC engine, a triple redundant hydrogen safety system, and a dedicated gaseous hydrogen fuel system. The vehicle and its test results are presented in this paper.

Spark knock pressure oscillations can be detected by a cylinder pressure transducer or by an accelerometer mounted on the engine block. Accelerometer-based detection is lower cost but is affected by extraneous mechanical vibrations and the frequency response of the engine block and accelerometer. The knock oscillation frequency changes during the expansion stroke because the chamber geometry is changing due to the piston motion and the burned gases are cooling. Spectrogram analysis shows the time-dependent frequency content of the pressure and acceleration signals, revealing characteristic signatures of knock and mechanical vibrations. Illustrative spectrograms are presented which yield physical insight into accelerometer-based knock detection.

An ionization probe head gasket (to IPHG) was used to investigate flame development in a 2.0L I4 engine with two in-cylinder fluid motions. A new technique was developed to display accurate flame contours at 2%, 10% and 50% mass fraction burned crank angles using the measurements of flame arrival time from the ion probes in conjunction with cycle simulations. The flame arrival and burn rate information is used to scale the relationship between flame radius and mass fraction burned from the cycle simulation to create accurate contours of the flame for each cycle. The tumbling motion inside the combustion chamber produced by the production intake ports convected the flame towards the exhaust side of the chamber. The geometry of the flame development was relatively unaffected by changes in speed and load.

The frequency of the pressure oscillations caused by spark knock depends on the temperature-dependent speed of sound in the combustion gases. Engine dynamometer tests showed a 6.5% (390 Hz) reduction in the knock fundamental frequency as the air/fuel ratio was swept from 13:1 to 20:1. Engine cycle simulation model predictions of maximum burned gas temperatures correlate well with the data. A robust knock detection system must be insensitive to the range of burned gas temperature (frequency of pressure oscillations) that will be encountered with a particular engine control system operating under the expected range of fuels and environmental conditions.