Theoretical And Damping Experimental Research Based On The First-Order Levitation Characteristics Of Magnetic Fluid

During the operation of a spacecraft in a weightless environment,it is susceptible to the influence of external and own vibration.These vibrations are usually difficult to attenuate on their own in a space environment without atmospheric damping,which affects important indicators such as the pointing accuracy and resolution of the spacecraft,and even causes structural damage until bringing catastrophic consequences.For the space environment where the vibration frequency is 0.3Hz～15Hz and the amplitude is 1.5mm～15mm,compared with other types of dampers,the magnetic fluid damping shock absorber is more sensitive to inertial force,with advantages of simple structure,small size,long life and without external energy supply.Attributable to the application background described above,this article has carried out the following work on the damper designed based on the first-order levitation characteristics of the magnetic fluid from the three aspects of theory,simulation and experiment:(1)The recent development and application of magnetic fluid in damping and vibration reduction are summarized.The essential differences between magnetic fluids and magnetorheological fluids are compared,as well as the development trends of magnetic fluid in tuned dampers and energy harvesters;(2)A calculation model suitable for the magnetic fluid damping shock absorber is established,and the basic theory of the application of magnetic fluid damping is studied.Which contains clarification of the magnetization and magnetic viscosity effects of magnetic fluid,Bernoulli equations and interface balance equations,etc.,and deriving the buoyancy equations of magnetic fluid,and analyzing the energy dissipation principle and vibration model of the magnetic fluid damper.The force of the main moving body is analyzes,including the theoretical analysis of the energy consumption of the vibration damping process,and the relevant theoretical analysis on the influence of the amount of magnetic fluid and the cone angle structure of the main moving body on the vibration damping performance are made;(3)Through comparison and selection,a magnetic fluid damping shock absorber based on the first-order suspension characteristics is determined,and its main components are respectively dimensioned,and the size constraints of the overall structure are calculated;The relevant theoretical analysis is made on the influence of the amount and the cone angle structure of the main moving body on the vibration damping performance,and the magnetic field simulation analysis and calculation of the shock absorber are carried out,and the magnetic field of the two-dimensional plane model and the two-dimensional axisymmetric model are compared and analyzed.And the magnetic flux density distributions corresponding to different magnetic pole schemes are analyzes,eventually the final magnetic pole arrangement is determined;(4)The experimental research on the magnetic liquid damping shock absorber designed is carried out.Since the damper is designed based on the first-order suspension characteristics,the first-order axial levitation force measurement experiment of the non-magnetic vibration damping block is first carried out,and the amount of magnetic liquid used to stably suspend the vibration damping block at the bottom of the shell is determined;the influence of different cone angles and different amounts of magnetic fluid on the vibration damping performance under the same amplitude,as well as the damping effects under different amplitudes,different cone angles and different amounts of magnetic fluid,and the final conclusion is reached by analyzing the experimental results.