起落架着陆油气混合缓冲器压力分析

Oleo-pneumatic Mixed Shock Absorber Landing Pressure Analysis of Landing Gear

飞机起落架在着陆过程中承受较大冲击载荷,致使起落架缓冲器内部承受较高的油压和气压,对缓冲性能有较大影响。首先,在缓冲器轴向载荷的基础上推导缓冲器各腔压力公式;其次,使用二质量系统建立起落架着陆运动微分方程;最后,应用MATLAB/Simulink搭建起落架着陆缓冲器压力仿真模型,利用此模型分析不同着陆速度下各腔压力随时间与缓冲器行程的变化规律,及不同正反行程回油孔面积的油腔压力对缓冲性能的影响。结果表明:在不同着陆速度下,各腔的压力在着陆过程的特定时刻呈现一定规律性;正行程回油孔不能太小,保证油液充满回油腔,反行程回油孔不能太大,保证油液充满主油腔;着陆冲击阶段的缓冲器内油压对柱塞的稳定性有影响。

The landing gear of an aircraft bears a large impact load during landing,which causes the internal shock absorber to withstand high oil pressure and air pressure,and the buffer performance is greatly influenced.Firstly,based on the axial load of the buffer,the pressure formula of each cavity of the buffer is deduced.Then,the differential equation of the landing motion of landing gear is established by using the two mass system.Finally,the landing gear buffer pressure simulation model is built by using MATLAB/Simulink,which is used to analyze the variation of the pressure of each chamber with time and buffer stroke at different landing speeds,and the influence of oil chamber pressure on the cushioning performance with different oil return areas.The results show that,at different landing speeds,the pressure of each cavity presents a certain regularity at a specific moment of the landing process;the positive stroke oil return hole should not be too small,ensuring that the oil fills the oil return cavity,and the reverse stroke oil return hole cannot be too large to ensure that the oil fills the main oil chamber;the oil pressure in the buffer during landing process affects the stability of the plunger.