FEM Analysis And Experiment Research On The Crankshaft And Cylinder Of A Medium-speed Diesel Engine

With the increase of the speeds and compact of the structure of diesel engines, the requirements of the power and reliability have increased. The load and the working conditions of the diesel engine parts become more severe. The strength of the diesel engine becomes more important. The temperature field, the structural stress field, the thermal stress field and the thermal& mechanical stress field of the diesel main parts(crankshaft& cylinder) are calculated by FEA in the paper. The temperatures of the heated parts of the diesel engine are measured by using the method of rigidity-plug. The boundary conditions are validated by measuring the temperature of cylinder line. The main research works are shown below:1,The dynamic analysis, including the motion and the force situation of the crankshaft-connecting rod and the piston of the model 6L21/32 diesel engine were as calculated by using software MATLAB. Combined Entry-level of the steel ships and dynamic result, the crankshaft strength was calculated by the empirical formula, which showed its strength can meet the requirements.2,The 3-D models simplified of the crankshaft and of the cylinder line were established by using the software PRO/E, which is consistent with the actual structure basically. With the reasonable boundary conditions and meshing, the crankshaft and the cylinder line were calculated by FEA software Patran and Nastran.3,Regarding the 8L21/31 medium-speed diesel engine as the research object, the temperature field of the cylinder line is calculated by using FEA and measured by using the rigidity-plug temperature measurement method. The boundary conditions of the cylinder line by using the empirical formula are validated.4,FEA model of the cylinder line of the model 6L21/32 medium-speed diesel engine is established by the same way. The temperature field, the structural stress field, the thermal stress field and the thermal& mechanical stress field of the cylinder line are calculated by using FEA method.The feasibility and efficiency in the design of new medium-speed diesel engine by using FEM is confirmed in the research on the crankshaft and the cylinder line.