The Prediction Of Engine Surface Vibration Impelled By Combustion

The noise of Engine includes the combustion noise, the mechanical noise and aerodynamic noise. Among it, the combustion noise of the whole noise is the most dominant part. So, the research on the combustion noise is particularly important. As the engine combustion noise and mechanical noise are difficult to separate, the study of combustion noise at home and abroad, mainly in combining the lower combustion noise and fuel economy. However, it is a guiding role for improving the accurate prediction of engine combustion noise, optimization of product design and noise reduction. Thus, this type of ATV400 Engine produced by JIANSHE industry group is researched and the prediction of combustion noise is carried out deeply.First, using GT-POWER software built working process simulation model of JS400ATV engine, it is to solve a variety of conditions and the pressure rise rate of cylinder pressure curves of the factors that affect the cylinder pressure; then, the establishment of three-dimensional solid model of the engine casing, ANSA software is used in order to definite the material and divide the meshes and it is imported into the ANSYS software to establish a finite element model of the shell of the engine. In this based, the finite element modal is analyzed. Therefore, the modal shows the dynamic performance of body structure and verify the finite element the model correctly. Then, the cylinder pressure and shaft bearing load are added to the finite element model; the transient analysis of the body structure is carried out in a engine cycle and the process of deformation of the body acted by the cylinder pressure is researched, which is represent for the situation of the vibration in the body. Finally, based on transient analysis, the acceleration of the body surface vibration is he boundary conditions and the transient radiated sound field of the engine block surface is predicted in the Sysnoise software; at the same time, the sound field radiated noise of the combustion characteristics is analyzed and researched.