Many problems associated with the design and development of hydrogen-air breathing internal combustion engines for automotive applications have been identified by various domestic and foreign researchers. This project addresses the problems identified in the literature, seeks to evaluate potential solutions to these problems, and will obtain and document a design data-base convering the performance, operational and emissions characteristics essential for making rational decisions regarding the selection and design of prototype hydrogen-fueled, airbreathing engines suitable for manufacture for general automotive use. Information is included on the operation, safety, emission, and cost characteristics of hydrogen engines, the selection of a test engine and testing facilities, and experimental results. Baseline data for throttled and unthrottled, carburetted, hydrogen engine configurations with and without exhaust gas recirculation and water injection are presented. In addition to basic data gathering concerning performance and emissions, the test program conducted was formulated to address in detail the two major problems that must be overcome if hydrogen-fueled engines are to become viable: flashback and comparatively high NOx emissions at high loads. In addition, the results of other hydrogen engine investigators were adjusted, using accepted methods, in order to make comparisons with the results of the present study. The comparisons revealed no major conflicts. In fact, with a few exceptions, there was found to be very good agreement between the results of the various studies.

The objective of this research effort is to obtain the design data-base covering performance, operational characteristics and emissions essential for making a rational decision regarding the selection and design of prototype hydrogen-fueled, air-breathing engines capable of being manufactured for general automotive use. To this end hydrogen-fueled internal combustion engines were divided into fourteen subgroups. An engine representative of each subgroup will be tested during the course of the three year program. The Project Program Plan calls for investigation of pre-intake valve closing fuel ingestion (Pre IVC) hydrogen-fueled engines during the first two years. Work accomplished during the third 3-month period of the project is reported. Activities in this quarter included: water injection experiments with the throttled and unthrottled engine mode of operation; design and construction of exhaust gas recirculation (EGR) equipment for use with the EGR experiments with the throttled and unthrottled engine configuration; construction of lithium-filled exhaust valves; and analysis of data for annual report preparation purposes. (LCL).

Progress in a 3 year research program to evaluate the performance and emission characteristics of hydrogen-fueled internal combustion engines is reported. Fifteen hydrogen engine configurations will be subjected to performance and emissions characterization tests. During the first two years, baseline data for throttled and unthrottled, carburetted and timed hydrogen induction, Pre IVC hydrogen-fueled engine configurations, with and without exhaust gas recirculation (EGR) and water injection, were obtained. These data, along with descriptions of the test engine and its components, the test apparatus, experimental techniques, experiments performed and the results obtained, are given. Analyses of other hydrogen-engine project data are also presented and compared with the results of the present effort. The unthrottled engine vis-a-vis the throttled engine is found, in general, to exhibit higher brake thermal efficiency. The unthrottled engine also yields lower NOx emissions, which were found to be a strong function of fuel-air equivalence ratio. (LCL).

The objective of this research effort is to obtain the design data-base covering performance, operational characteristics and emissions essential for making a rational decision regarding the selection and design of prototype hydrogen-fueled, air-breathing engines capable of being manufactured for general automotive use. To this end hydrogen-fueled internal combustion engines were divided into fourteen subgroups. An engine representative of each subgroup will be tested during the course of the three year program. The Project Program Plan calls for investigation of pre-intake valve closing fuel ingestion (Pre IVC) hydrogen-fueled engines during the first two years. Work accomplished during the second three months of the project is reported. Activities during the second quarter concentrated on: final apparatus debugging, engine break-in, preliminary testing to determine qualitative apparatus operating characteristics, rearranging of the proposal test schedule and performing of tests with engine 1 (carbureted, throttled, no H2O injection, no EGR and engine 4 (carbureted, unthrottled, no H2O injection, no EGR. The details of these activities are described.