柴油机气缸套空化现象与空蚀机理分析OACSTPCD

Aiming at the cavitation phenomenon that occurs during the working process of diesel engine cylinder liners due to coolant cavitation,based on the numerical simulation of cavitation flow of a single cylinder cooling water jacket during the working process of diesel engine cylinder liners,combined with the simulation of near-wall multi-bubble collapse process,the cavitation phenomenon and cavitation erosion mechanism of diesel engine cylinder liners were studied from macro and meso perspectives.Firstly,based on the simulation of single cylinder cooling water jacket,it is found that the vibration of cylinder liner wall leads to cavitation of coolant and a large number of cavitation bubbles are generated.Then,the collapse process of near-wall bubbles was simulated,and the effects of the spacing and num-ber of bubbles on the collapse of multi-bubbles were analyzed.The results show that the smaller the bubble spacing is,the longer the collapse time is.When the center spacing of bubbles decreases from 0.050 mm to 0.025 mm,the collapse pressure of near-wall bubbles increases by 49.82%,and the mi-crojet velocity increases by 10.56%.When the number of bubbles is increased,the collapse pressure shows a trend of first increasing and then decreasing.When the number of bubbles increases from two to ten,the velocity of microjet increases by 44.93%.Research has shown that the micro jet produced by cavitation bubbles collapse has a high water hammer pressure,which acts on the cylinder liner wall and causes corrosion damage,and is the fundamental cause of cavitation erosion of the cylinder liner.