The Dynamic Characteristics Research Of The Diesel Engine

When diesel engine develops toward heavy power, lightweight, reducing specific fuel consumption and reducing emissions, its vibration and noise will become more important. So investigation of dynamic characteristics of combined structure was studied in this paper, in order to know and analyze its vibration. Research results would be lessons and referring value to analysis and control vibration and noise of the whole diesel.At first this paper makes a full description on research situation of dynamic characteristics of diesel engine at home and abroad, the corresponding research method and software.Then through the software UG we build the 3-D solid model of diesel engine block and cylinder head; through the software Hypermesh we divide the mesh, which is converted to finite element model; through the software ABAQUS we combine diesel engine block with cylinder head to simulate its actual working state, subsequently, we do the free modal analysis and constrained modal analysis, natural frequencies and modal shapes of the diesel engine were worked out. We find out the weak link of vibration of the whole diesel, which would be lessons to strength design of diesel, and provide a basis for subsequent investigation of dynamic characteristics.The modal experiment of diesel engine block is based on experimental modal method applied with Belgium LMS, the results show that the data achieved by experiment are coincident with the data calculated by finite element method, which verifies the correctness of the finite element model, and establishes a foundation for the dynamic characteristics analysis.At last based on modal analysis of the diesel, we do the steady-state kinetics analysis of this model using a mode superposition method. We get the dynamical response curve of the diesel surface, and find out the sympathetic vibration frequency; Meanwhile, we get the vibration velocity distributions of the diesel surface, and predict the main noise source, and measures for vibration and noise reduction are suggested.