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چکیده
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Reduction of fuel consumption in cars is always a hot issue for manufacturers, politicians, and environmental activists. The injector is one of the components in car's fuel system that plays a significant role in the reduction of fuel consumption. The development of four-stroke spark-ignition engines that were designed to inject gasoline directly into the combustion chamber was an important worldwide initiative of the automotive industry development of smart materials (e.g., piezoelements and magnetostrictives materials) with high-frequency bandwidth draws many researchers and companies to develop next generation of injectors by these materials. High-frequency response combined with miniaturization potential of these materials help the designer to use multiinjections in each combustion cycle. Therefore, emission of NOx pollinations is considerably reduced. Piezoelectric fuel injectors are developed for hydrogen-fueled, diesel, and gasoline combustion engines [1]–[3]. However, a commercialized piezoelectric injector (e.g., J43Px) needs high voltage of 1000 V for a displacement of 130 μm. Furthermore, delamination in piezoelectric stack causes low life of 200 h [1] for piezoelectric injectors. Driving with low voltage and generating high strain (displacement) make giant magnetostricitve materials good candidates for these purpose. Olabi et al. proposed a CNG injector with magnetostrictive material without any performance test [4]. Drawbacks of piezoelectric in gasoline direct injector (GDI) were also good motivation for authors to use magnetostrictive material for developing a GDI with new nozzle configuration. Modification of the outlet nozzle comes from this fact that characteristics of outlet spray plays a significant role in efficiency of combustion. Injector's length, spray cone angle, spray width, spray penetration distance, and droplet size are considered as spray characteristics [5], [6]. Here, a conventional hollow cone nozzle is not used because of complex m
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