转套式配流系统凸轮槽型线对空化特性的影响

Influence of Cam Groove Profile of Rotating-Sleeve Distributing-flow System on Cavitation Characteristics

空化引起的振动和噪声会影响转套式配流系统性能和寿命,转套的凸轮槽型线与空化特性关系密切。在线性凸轮槽型线基础上提出了3种新的凸轮槽型线,建立了相应的型线方程,随着曲轴转动,线性型线对应的转套转角波动最小、样条型线最大。建立了系统空化流体力学模型,通过仿真,发现4种型线对应的最大气体体积分数均随工作转速升高单调递增,总体看来线性型线最好;空化占比随转速增大而升高,同转速条件下线性凸轮槽型线对应空化占比最小;容积效率随转速增加单调递减,开始比较平缓,速度较高时降低较快,总体看来线性型线对应的容积效率最高。

Vibration and noise caused by cavitation have an impact on the performance and life of the rotating-sleeve distributing-flow system. The cam groove profile of the rotating sleeve is closely related to the cavitation characteristics. Three new types of the cam groove profiles are designed based on the line cam groove profile and the linear equations are established. With the rotation of the crankshaft, the fluctuation of the rotating sleeve angle of the line profile is the smallest and that of the spline profile is the largest. The cavitation hydrodynamic model is established. The maximum gas volume fraction of four types of profiles all increases monotonously with the increase of the rotating speed and one of the line profile is the best in general. The proportion of cavitation also increases with the increase of the rotating speed, and one of the line profile is the smallest at the same rotating speed. All volumetric efficiency decreases monotonously with the increase of rotating speed. But it decreases slowly at low speed and faster at high speed. Overall , the line profile corresponds to the others, its volumetric efficiency is the highest.