中文摘要：

液压缸是驱动高速大功率直线运动负载的首选元件,针对该负载的高精度可预知运动控制这一问题.为了了解液压缸在高速运行速度下的运动特性和动力学特性,以理想化的液压缸为对象,利用Fluent软件及动网格技术,对液压缸缸内流动流场和活塞运动过程进行了数值仿真,探讨了压差、供油口大小和工作行程等参数对活塞动态特性的影响.研究结果表明,液压缸活塞运动速度在启动瞬时和终止瞬时均出现了大幅度的波动,在其余运动过程中,运动速度表现为某一均值和规则性高频脉动值相叠加的形态;压差越高,脉动频率越高且脉动幅值越大;油口直径增大,速度脉动频率增高,脉动幅值相应减小;活塞上合力在启动瞬时和终止瞬时出现波动,在稳态运动过程中,合力表现出与速度类似的形态.该研究同时还给出了活塞速度与工作行程大小的关系.

英文摘要：

Hydraulic cylinder is the first choice for driving the high speed and high power linear motion load.Aiming at the predictable motion control with high precision to the load,it must be understanded the kinematics and dynamics of the hydraulic cylinder at high running speed.An idealized hydraulic cylinder was taken as the object.The internal flow field of hydraulic cylinder and the piston movement process were simulated by using Fluent software and dynamic mesh technology,and the influence of differential pressure,the size of oil port and the working stroke on dynamic characteristics of piston were discussed.Results indicate that,the velocity of piston appeared significant fluctuations in the instants of start and end,in remaining movement process,the form of movement speed performed to be a mean value overlaid by regular high frequency pulse,a high pressure gives high pulse frequency and big amplitude of pulse; a big size of oil mouth diameter gives high pulse frequency and low amplitude of pulse accordingly.The resultant force on piston appears fluctuations in the instants of start and end,in steady-state movement process,the resultant force performs a similar form of speed.Meantime the relationship between piston speed and the working stroke is given.