The geometry of the diesel fuel injection nozzle and fuel flow characteristics in the nozzle significantly affects the processes of fuel atomization, combustion and formation of pollutant emissions in diesel engine. To improve the process of fuel injection, CFD packages are used. Since CPU times are often high, partial models are used for the analysis. In presented paper the influence ,of different density of mesh on the cavitation phenomena is being analysed. The theoretical backgrounds of the cavitation occurrence presented in the first part of the paper are followed by the numerical analyses of two-phase flow in same simplified nozzle models. The numerical analyses are made using computation fluid dynamic (CFD) program Fire. The numerical analysis is made for two different types of fluid, diesel (D2) and biodiesel (B 100). Numerical analysis also includes various densities of meshes and their influence on results. The two-phase flow is analysed using a two-equation approach, where all conservation equations are solved for every phase. Numerical analysis results are compared to the experimental observations of the two-phase flow available from the literature. The results are compared for various meshes and various fluid types. The results show that higher pressure yields mode cavitation and point out the importance of mesh densities.
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W pracy określono rodzaje zużycia, którym podlegają rozpylacze wtryskiwaczy silników okrętowych. Dla partii rozpylaczy silników średnio-obrotowych przeznaczonych do napędu prądnic, eksploatowanych w naturalnych warunkach wykonano badania eksperymentalne. Zastosowano oględziny oraz badania stanu powierzchni z zastosowaniem aparatury badawczej. Na podstawie przeprowadzonych badań dokonano identyfikacji zużycia. Zasadniczo występowały jednocześnie różne rodzaje zużycia. W artykule tym podjęto również próbę określenia miejsc podlegających intensywnemu zużyciu.
EN
At work kinds of the wear which of injector nozzless of marine diesel engines are subordinate were determined. For the party of injector nozzles of medium-speed marine engines of the generators intended for the drive, operated in natural conditions experimental investigations have been carried. There have been applied visual inspections and investigations of the state of the surface were applied with applying research apparatus. On the basis of investigations carried out they established the identity of the wear. Fundamentally at the same time different kinds of the wear appeared. In this article they also made an attempt at determining places being subject to an intensive wear.
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