Study on the coolant pressure of internal combustion engines through vibro-acoustical analysis of a real cylinder block structure

Abstract

Liner cavitation is caused by water pressure fluctuation in the water coolant passage of internal combustion engines. The high-speed re-entrant jet and shock wave following the implosion of cavitation bubbles cause cavitation erosion on the wet cylinder liner surface. The present work proposes a numerical method to predict the water pressure fluctuation of engine systems considering acoustic features of water coolant passage. The effect of the geometry modification of water coolant passage is evaluated. The water coolant passage acoustic field is introduced into the engine system containing a crankcase, a gear case, a cylinder head and an injection pump. The water coolant pressure fluctuation and engine vibration are calculated for engine systems with different exciting forces. The cross-sectional pressure distribution of water coolant passage and the longitudinal pressure distribution along thrust side of liner at top dead center are discussed. It is revealed that the pressure distribution is influenced by certain acoustic modes. The pressure fluctuates strongly at the top dead center, which is conductive to bubble formation and explosion.