单联和双联液压管路系统流固耦合振动特性分析

Analysis of Fluid-structure Interaction Vibration Characteristicsof Single and Duplex Hydraulic Piping Systems

飞机液压管路常用于发动机的燃油与滑油输送,由不同种类的卡箍将其固定,组成液压管路系统。根据管路形状不同,连接形式多样,常见的包括单联液压管路系统和双联液压管路系统。为避免复杂工作环境下因流固耦合振动而导致管路系统出现振动失效等问题,以典型的单联和双联液压管路系统为对象,基于管路本体的Euler-Bernoulli梁假设和黏弹性材料假设,采用牛顿法分别对管路和管路中的流体进行受力分析,再通过加减消元推导出管路系统的运动微分方程。然后,进行无量纲化处理,依据管路两端一般支承的边界条件求解出管路系统模态函数和频率方程,并通过Galerkin法将单联和双联管路系统的运动微分方程在模态空间内展开,进行振动特性的计算分析,获得内部液压油的流速、压力以及质量比对液压管路系统流固耦合振动特性的影响。

Aircraft hydraulic pipelines are often used for the delivery of engine fuel and lubricating oil.They are fixed by different types of clamps to form hydraulic pipeline systems.Since the different shape of the pipelines,their connection forms are various.The common ones include single hydraulic pipeline system and duplex hydraulic pipeline system.In order to avoid the vibration failure of the pipeline system due to fluid-structure coupling vibration in complex working environments,this paper takes typical single and duplex hydraulic pipeline systems as the object for study.Based on the assumption of Euler-Bernoulli beam and visco-elastic material of the pipeline body,the stresses of the pipeline and the fluid in the pipeline are analyzed by using the Newton's method.Then,the differential equation of motion of the pipeline system is derived by adding or subtracting elements.Then,the dimensionless processing is carried out,and the modal function and frequency equation of the pipeline system are solved according to the boundary conditions of the general support at both ends of the pipeline.The differential equations of motion of the single-connected and double-connected pipeline systems are expanded in modal space by means of the Galerkin method.The vibration characteristics of the pipeline system are calculated and analyzed.The effects of the flow rate,pressure and mass ratio of the internal hydraulic oil on the fluid-structure interaction vibration characteristics of the hydraulic piping system are obtained.