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One important parameter influencing mixture formation and spray/wall interaction within engines is the geometry of the nozzle. In contrast to Diesel nozzles, the influence of the orifice geometry on spray formation has hardly be investigated for gasoline nozzles. In order to demonstrate the potential of adjusting the nozzle geometry of a modern GDI nozzle, we compare two six-hole, high-pressure nozzles with an identical structure, but different rounding radius of the orifice hole-inlet and different orifice hole-geometries: nozzle A with a rounded inlet and an orifice length to diameter ratio of 3/2 and nozzle B with a sharp inlet and an orifice length to diameter ratio of 1. In a first measurement campaign the spray formation is visualized using high-speed shadowgraphy imaging. The results show differences in spray angle and penetration depth. In a second measurement campaign we examine the spray/wall interaction and wall film formation by means of infrared thermography. The thermography measurements indicate that the geometry of nozzle B produces sprays with beneficial characteristics. This is very important for a clean combustion process and a decrease of soot emissions. 相似文献
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Mintesnot G. Woldeamanuel Rita Cyganski Angelika Schulz Andreas Justen 《Transportation》2009,36(4):371-387
For economic and environmental policy formulation and with the effort of creating less car dependent societies, it is important
to study the changing characteristics of car ownership in a household through time as well as factors responsible of these
variations. There is a vast body of literature on empirical studies of car ownership and use. These studies have investigated
the socio-economic background of the decision maker, the built environment and the perception associated with owning a car
as determinant factors of car ownership and use. In most cases, these analyses have been carried out using cross-sectional
data sets. However, the analysis of factors determining changes in travel behavior of an individual or household requires
information on their behavior over time (longitudinal data set). In this study, the German Mobility Panel (1996–2006) is used
to examine variation of car ownership through time and across households. The panel data modeling results showed that there
are variations of car ownership between households whereas changes in car ownership of a given household over time (within
household variations) are insignificant. The influence of other factors such as the households’ socio-economic background,
the availability of public transportation and shopping/leisure facilities, perception on parking difficulties and satisfaction
with existing public transportation services on the car owning characteristics of households is also presented and discussed
in this paper.
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Andreas JustenEmail: |
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This paper presents the results of a research into railway regulation and liberalisation in Italy, France, Germany and Spain. The analysis covers the relationship between the State and the rail companies, network access conditions by operators, slot allocating and pricing schemes and how public service obligations are defined, financed and regulated. 相似文献
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