Due to world trend on the emission regulations and greater demand of fuel economy, the research on advanced diesel injector designs is a key factor for the next generation diesel engines. For that reason, it is well established that understanding the effects of the nozzle geometry on the spray development, fuel-air mixing, combustion and pollutants formation is of crucial importance to achieve these goals.In the present research, the influence of the injector nozzle geometry on the internal flow characteristics is studied. For this purpose, ten single-hole diesel injectors differing in the orifices degree of conicity (five cylindrical, five conical) but with similar nozzle flow capacity have been characterized geometrically (measurements of nozzle outlet section) and hydraulically. The mass flow and momentum flux rates have been measured for a wide range of experimental conditions. Special attention is given to study the cavitation phenomenon since the cylindrically-shaped nozzle orifices are expected to propitiate cavitation due to abrupt changes in flow direction. The study has been carried out with two different fuels: n-Dodecane and commercial diesel, thereby the effect of the fuel properties is also analyzed.The results show that the measured nozzle outlet diameters are higher than the nominal specification for both nozzle types. As expected, the onset on cavitation on the cylindrical nozzles has been identified causing a reduction on the injected mass for all tested conditions. The effective diameter for the cylindrical nozzles have been found to be around 180 µm (geometrical diameter ~212 µm) and around 190 µm (geometrical diameter ~191 µm) for the conical ones. Finally, the higher density of Diesel with respect to n-Dodecane have resulted on mass flow rates around 8% over the n-Dodecane values for the same test conditions.ii

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Se usa un algoritmo para simular y estimar ahorros en los costos de consumo eléctrico de las micro, pequeñas y medianas empresas (MIPYMES) del sector de alimentos, y su confiabilidad ha sido verificada en una empresa. La metodología contempla la normativa peruana para determinar los cargos correspondientes a cada tarifa eléctrica, y se puede aplicar a cualquier MIPYME en baja y media tensión. A partir del perfil de consumo y tarifa eléctrica, se simularon los escenarios del cambio de tarifa y del factor de calificación en tres MYPIMES representativas. Con esto fue posible identificar la tarifa más conveniente para cada empresa, considerando la calificación del usuario de presente en hora punta (HP) y fuera de hora punta (FHP). Los resultados satisfactorios de la simulación demuestran que la metodología representa una herramienta importante para incrementar la productividad y competitividad de estas empresas.

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