Research On Structural Dynamics And Cavitation Of Cylinder In Multi-cylinder Engine Block

Cylinder-piston system is the heart of internal-combustion engine. Cylinder liner cavitation is one of main disabled form. So it is significant to resolve the cavitation problem which enhances the use life and guarantees economical and reliable function. Cavitation erosion is caused by high frequency vibration of engine body and high pressure impulse of coolant. In this dissertation, we firstly introduce the position and characteristics of cavitation. Then we elaborate the influencing factors of the cavitation and analyse the theory of cavitation. On this basis, many preventive measures are presented. Furthermore, According to drawing, the solid modal of body, cylinder and coolant of 4105 diesel engine is conducted using ANSYS software. And the model is simplified. The finite elementmodal is gained by partitioning gridding. The model is established by applyling APDL, which prepares for optimizing analysis.Oil film pressure and the friction force between piston and cylinder influence movement of piston skirt greatly. Formerly these two forces are ignored. On the basis of the mathematic model about the tribology and dynamic coupling of the multi-cylinder engine cylinder- piston system, we apply and improve the former program to compute the oil film pressure and the friction force. The improved program can be combined with ANSYS which realizes the dynamic coupling in essence.Dynamic analysis is executed after all loads are added on tim model. The stress and the deform cloud chart of the cylinder are obtained, which is close to the really cavitated one. On the other hand, the modal analysis is done to cylinder and body. And the week area is got, which also propose bases for the design of the body. This indicates that the analysis procedure is available which can be used to analyze the newly designed cylinder and propose strong bases for designing more reasonable cylinder.