| Aircraft shock absorber system plays an important role in the safe landing of aircraft and also provides a guarantee for the comfort of passengers.Modern aircraft mostly adopt oleo-pneumatic shock absorber.The oil liquid in the shock absorber flows through the oil orifice with high speed to produce damping force.The characteristics of the oil orifice and the viscosity of the oil have a significant impact on the damping characteristics of the shock absorber.However,the existing aircraft design manual has a rough study on damping,lacking studies on the influence of oil orifice characteristics and oil viscosity on damping characteristics,so the relevant damping characteristics of oil orifice are important research objectives of this paper.This thesis researched on the oil orifice of the shock absorber,using the method of classical fluid mechanics to analyzes the characteristics of different oil orifice in the landing gear damping.Analyzed influence factors of the damping coefficient.By using ICEM-CFD to build the modeling of oil orifice,using Computational Fluid Dynamics(CFD)software FLUENT,flow field is calculated in different temperature and viscosity.By the computer simulation experiment,to research on influence factors of the damping coefficient,two kinds of oil orifices,the tenuous orifice and the thin wall orifice,were simulated.In addition,the oil orifice with rounded edge and sharp edge was simulated respectively by using FLUENT.The results verified that if the oil orifice edge was rounded,the damping coefficient of the oil orifice would be greatly reduced.At the same time,to study of the landing gear shock absorber oil orifice,Fluid-Damping-Characteristics-Test-Platform is developed,and the test platform includes test bench clamp system,servo loading system,data acquisition system,and the temperature control system.It can load and measure the tested object precisely.By using the test platform,we get the test results that verify the validity of the simulation conclusion. |
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