液压冲击器流场分析

Fluid field analysis for a hydraulic impactor

通过流体力学的相关理论分析了压力反馈式液压冲击器的整体流场,建立了液压冲击器流场的基本方程;对冲击器的力学模型进行简化,并求解了流场中的速度分布和流动损失情况。为了形象地得出冲击器流场的参数变化规律,利用Catia软件和Fluent的前处理器Gambit对冲击器的流场进行了建模,并利用Fluent软件对液压冲击器的瞬态流场进行了模拟求解。对比CFD模拟的结果和求解基本方程的结果,结果比较吻合。对瞬态流场的分析表明,在进油口截面突然变化的部位流速变化较大,远离这一区域后开始趋于平稳,而冲击过程中的中腔出油口存在速度较大的区域。另外,随着进油速度增大,流场的紊流情况加剧,流动的损失量呈抛物线增加。

Flow field in a hydraulic pressure feedback impactor was analyzed here with the theory of Hydromechanics.Differential equations of motion and basic flow equations for fluid field of a hydraulic impactor were built and the mechanical model of the impactor was simplified.Velocities of fluid and flow losses were solved,too.In order to obtain intuitively the varying law of the flow field of the impactor,the flow field model of the impactor was built using Catia software and Gambit,and the transient flow field of the impactor was simulated with Fluent software.The CFD simulation results agreed well with the results of solving the basic equations.The analysis of the transient flow field showed that the velocity changes largely at inlet field with its cross-section varied suddenly and becomes steady far away this field;however,at central outlet there exists a larger velocity field;in addition,unsteady flow aggravates and flow losses increase as a parabolic curve with increase in velocities at inlet.