| Recently, people intensively concern about energy resource and environment pollution so that the integrative performance of engine is endlessly required to improve. Therefore, the capability of design and research on injector with high injection pressure and rate is to be paid more and more attentions. It is very difficult to accurately reflect the actual work state of some parts in engine by using traditional theory formula. Nowadays, a new method named finite element method with particular characteristic has been used widely in analysis of these complex parts. This paper has stated investigation tendency and key techniques applied on injector. In this paper, finite element method is employed to analyze the rationality of structure design and influence on performance in 190 series diesel injector. First, this paper has analyzed the motion and impact stress of needle by using stress wave theory and finite element method, and compared some performance differences between low-inertia injector and general injector; Second, simulated the flow in the nozzle by using CFD (Computational Fluid Dynamics) finite element method, considering the compressibility of fuel and viscosity changing with the variety of the pressure and temperature. Through analysis, the real situation of the flow field in the nozzle can be predicted, the influence on flow state with the change of some structure parameters in the nozzle can be worked out, and consequently some information about improvement can be obtained. The analysis study of this paper is based on tests of injection system of engine series, including 108, 135, and 190 type. The results can be applied to provide theory basis for injector improvement in the course of its development and trial-manufacture.
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