Research On Motion Characteristics Of Inertia Momentum Wheel Based On Magnetohydrodynamics

At present,the diversified task demands,such as high-precision earth observation,aircraft search,discovery and tracking as well as on-orbit satellite reconstruction,have put forward higher requirements for the attitude control performance of satellites.The inertial momentum wheel based on magnetohydrodynamics is featured by small size,light weight,long service life,high precision and impact resistance,which make it an ideal actuator for the spatial ultra-quiet platform of satellites.There is little research on magnetohydrodynamics momentum wheel in China.In this dissertation,a magnetohydrodynamics momentum wheel with axial magnetic field structure is proposed.In order to study the motion characteristics of the conductive fluid ring of magnetohydrodynamic momentum wheel,the main work in this dissertation is as follows:1.A simplified model is established under ideal assumptions.The simulation results are verified by the simulation software Fluent.Based on the Ohm’s law and the Navier-Stokes equation of incompressible fluids,the transfer function of the conductive fluid ring,which is the key component of the momentum wheel,is theoretically derived.Next,the simulation software Fluent is applied to perform numerical simulation on the theoretical results.2.The working characteristics of the momentum wheel are related to the structure of the conductive fluid ring,the magnitude of the magnetic induction intensity and the physical parameters of the conductive fluid material.The mechanism of the action of various factors on the flow rate is studied by numerical simulation.The secondary flow is characterized by the circumferential flow velocity-flow function model.The factors affecting the magnitude of the secondary flow are analyzed.It is known that the magnitude of secondary flow is proportional to the external voltage and inversely proportional to the external magnetic induction.This study can provide a basis for the design and optimization of the magnetohydrodynamics momentum wheel.3.The experiment of measuring the angular velocity of the magnetohydrodynamics momentum wheel is carried out.The air-floating turntable is used as the carrier of the momentum wheel.The angular velocity of the momentum wheel machine under various input signal conditions is tested,the amplitude of the input signal is changed,and the experimental measurements of angular velocity,output torque and angular momentum are compared with the theoretical calculation values,and the causes of the deviation are analyzed.