Thesis (Ph. D.)--Pennsylvania State University, 2004. / Vita. Includes bibliographical references (p. [196]-205 of photocopy). Abstract and 24 page preview available online.

An innovative diesel-electric power supply and propulsion system is a highly integrated electric system consisting of power generation, power distribution, and electrical drives. Every component of this system constantly produces operating data, which is read and evaluated by several programmable logic controllers, which in turn produce control signals. This thesis presents a diagnostic system that collects the operating data and control signals from all power supply, propulsion, and control components on board, saves them to a hard drive, and enables an engineer to view the data remotely over the internet, in real-time as well as in retrospect. An industrial computer, certified for on-board use, is embedded into the ship’s control unit, autonomously running the software that retrieves the data via an industrial Ethernet connection and makes it available to a remote user through a web interface or a database connection.

Designers of engines have always looked for ways to improve the power to weight ratio of mobile internal combustion engines. This was especially true in aircraft engine design and engines for various forms of racing. Today designers are looking for ways to make everything from cars to road tractors to farm tractors lighter and thereby more efficient. In addition, in many cases these vehicles only need the maximum power that an engine can produce for a small amount of time. What is needed is a small, lightweight engine with the ability to produce a large amount of power for a short duration. The work here describes one possible method for constructing just such a type of engine. By adding a combustion chamber in the exhaust flow between the engine exhaust valve and the turbine inlet on a turbocharged diesel engine, it should be possible to increase the turbine temperature. This will in turn allow the turbine to deliver more power to the compressor and create a higher inlet pressure and allow the engine to create more power. This paper describes both a computer simulation and an engine with this combustion chamber installed. There were however, problems with both the simulation as well as the test engine. While no quantitative data was obtained from the test engine, some valuable observations were made. The computer simulation yielded results and from these results and observations made while testing the engine with the combustion chamber installed it was determined that this design shows promise of creating an engine with higher specific power. / Master of Science

Thesis (Ph. D.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Low temperature combustion (LTC) is an appealing new method of combustion that promises low nitric oxides and soot emissions while maintaining or improving on engine performance. The three main points of this study were to develop and validate an engine model in GT-Power capable of implementing LTC, to study parametrically exhaust gas recirculation (EGR) and injection timing effects on performance and emissions, and to investigate methods to decrease pressure rise rates during LTC operation. The model was validated at nine different operating points, 3 speeds and 3 loads, while the parametric studies were conducted on 6 of the 9 operating points, 3 speeds and 2 loads. The model consists of sections that include: cylinders, ports, intake and exhaust manifolds, EGR system, and turbocharger. For this model, GT-Power calculates the combustion using a multi-zone, quasi-dimensional model and a knock-induced combustion model. The main difference between them is that the multi-zone model is directly injected while the knock model is port injected. A variety of sub models calculate the fluid flow and heat transfer. A parametric study varying the EGR and the injection timing to determine the optimal combination was conducted using the multi-zone model while a parametric study that just varies EGR is carried out using the knock model. The first parametric study showed that the optimal EGR and injection timing combination for the low loads occurred at high levels of EGR (60 percent) and advanced injection timings (30 to 40 crank angle degrees before top dead center). The optimal EGR and injection timing combination for the high loads occurred at low levels of EGR (30 percent to 40 percent) and retarded injection timings (7.5 to 5 crank angle degrees before top dead center). The knock model determined that the ideal EGR ratio for homogeneous charge compression ignition (HCCI) operation varied from 30 percent to 45 percent, depending on the operating condition. Three methods were investigated as possible ways to reduce pressure rise rates during LTC operation. The only feasible method was the multiple injection strategy which provided dramatically reduced pressure rise rates across all EGR levels and injection timings.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xiii, 164 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 85-87).

Thesis (M.S.)--West Virginia University, 1999. / Title from document title page. Document formatted into pages; contains x, 96 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 61-62).

published_or_final_version / abstract / Mechanical Engineering / Doctoral / Doctor of Philosophy

An existing encoder system was analyzed to determine why the system had failed. This encoder system was found to have slipped off the crankshaft, resulting in the need for a new encoder mount system. A new encoder mount was designed and installed on a Detroit Diesel 3-53 engine. The encoder mount was designed to ensure positive contact with the crankshaft while not allowing the mechanism to have the same type of failure that was determined. During the validation of the encoder, the push rod connected to the fuel injector rocker arm failed, preventing further validation of the system. The failure of the push rods is described.

En la actualidad, el biodiesel constituye una alternativa y un complemento al diesel para reducir la contaminación ambiental y la escasez de combustibles fósiles, siendo un medio de energía renovable menos contaminante que el diesel convencional. Las características de este combustible lo hacen apropiado para funcionar en motores de encendido por compresión, sin tener que realizar cambios importantes al diseño del motor. En el presente trabajo se realizó una evaluación experimental del efecto de la utilización de 3 mezclas de diesel y biodiesel en porcentajes volumétricos de 5%, 7,5% y 10% (DB5, DB7,5 y DB10) sobre los parámetros relacionados al consumo de combustible y las emisiones contaminantes. Las pruebas experimentales se realizaron en un motor Cummins de encendido por compresión, 6 cilindros, 6.7 litros, turbo cargado; instalado en un banco de pruebas dinamométrico en el Laboratorio de Energía de la Pontificia Universidad Católica del Perú. Las pruebas experimentales consideraron 4 regímenes de giro (1000, 1300, 1600 y 2000 rpm) y 4 niveles de carga: 9.4, 18.8, 28.2 y 37.5 kPa, en términos de presión media efectiva. Ambas variables fueron establecidas como datos de entrada para cada ensayo y a partir de estas se midieron y calcularon los parámetros requeridos. En términos de desempeño del motor, se calculó la potencia efectiva, el consumo específico de combustible y el rendimiento efectivo para las 3 mezclas de diesel y biodiesel utilizadas. Los resultados indicaron que la potencia efectiva aumentó conforme se incrementó la velocidad de giro y carga del motor, pero se mantuvo constante para las tres mezclas. El consumo específico de combustible aumentó conforme se incrementó el porcentaje de biodiesel en la mezcla. El rendimiento efectivo presentó un aumento conforme se incrementó la carga en los ensayos, pero disminuyó al utilizarse más biodiesel en la mezcla. Respecto a los contaminantes gaseosos, se midieron el monóxido de carbono (CO), dióxido de carbono (CO2) y óxidos de nitrógeno (NOx). A partir de los valores registrados, se obtuvieron las variaciones porcentuales más significativas entre las emisiones encontradas para las 3 mezclas empleadas. Las emisiones de CO y CO2 disminuyeron a medida que se aumentó el contenido de biodiesel en las mezclas, presentando el CO las variaciones más significativas. Por otro lado, las emisiones de NOx aumentaron conforme se incrementó el porcentaje de biodiesel en la mezcla. Los aumentos porcentuales más altos se encontraron a mayores cargas y velocidades más altas. / Tesis