Study on the liner cavitation induced by piston slap

Abstract

The internal combustion engine encounters the cavitation erosion induced by piston slap. The impact vibration between the piston and cylinder liner generates the pressure fluctuation on the coolant side of the liner and leads to occur the cavitation in the case that dynamic pressure falls below its vapor pressure. Authors have already developed the analytical method to predict the liner vibration caused by the piston slap. In this paper, the acoustic characteristic of the water coolant passage of the actual diesel engine in vacuum condition is analyzed and compared with the measured result. Then, theoretical method to determine the coupled vibratory characteristics of structure and water acoustic field is developed. This method employs modal analysis technique and Finite Element Method. Calculated results of vibro-acoustic characteristics of the engine block and the water coolant passage are compared with the measured ones. Water pressure in the water coolant passage at the running condition is calculated and the possibility of the liner cavitation occurrence is discussed.