液体弹性模量和异管径连接面对压力瞬变影响

The Effect of Fluid Bulk Modulus and the Pipe Junction with Different Diameters on Pressue Transients

通过研究液压系统中油液在管道中流动时发生压力瞬变的物理特征 ,选择截面两端面积相差较大的液压缸进出口处的条件进行试验 .实验结果表明 ,油液弹性模量随压力而变化的特性(尤其是当工作压力 p <2 .94MPa时 ) ,以及管道系统中异管径连接处的动量变化 ,对计算压力瞬变参数的影响显著 ;阐明了以往采用特征线法计算管道系统压力瞬变误差较大的原因 ,并提供了相应的计算方法 .

Based on the physical feature that a pressure transient occurs when the fluid flows in the hydraulic system and through the experiment of pressure transient on the entrance and egress of the cylinder, this paper studies the characteristics of the fluid bulk modulus which changes with its pressure, especially in pressure p <2.94 Mpa. Experimental results show that the change of the momentum at the pipe junction with different dia_ meters and the fluid bulk modulus exert a great influence on the parameters of the the pressure transient. It thus illustrates the root cause for the errors in the calculation of actuating parameters of the pressure transient by the traditional method. The paper also presents the related methods of calculation.