Research On Characteristics Of Porous Gas Bearing With High Pressure And Heavy Load Passing Through The Gap

Ground-based aerospace microgravity experiments are necessary tasks to ensure the development of space safety,and have an important role in promoting the development of the aerospace field.The simulated aerospace microgravity experiment uses the air flotation platform and mechanical means to float the spacecraft to simulate The porous gas bearing has thousands of orifices,which can provide high bearing capacity and static stiffness as gas bearings.It can be used as the best choice for carrying spacecraft in air flotation platforms.Due to the high precision and high Cost of the air-floating platform,the use of multiple small platforms to form a floating platform to solve the problem of flatness,but this will cause gaps between the small platforms,which has an impact on the microgravity simulation experiment.In order to solve This problem,this paper studies the static bearing characteristics of porous gas thrust bearings based on over-slit cond Itions and conducts experimental research.The mathematical model of the porous gas thrust bearing based on the over-slit condition is established.According to the actual situation,the corresponding assumptions are put forward.The gas motion model is established based on Darcy's law in the porous medium.In the bearing air gap,the gas continuity equation is applied.The gas motion equation and the gas state equation and the velocity slip theory at the interface of the porous bearing establish the Reynolds equation inside the gas gap of the porous gas thrust bearing in the over-slit condition.The meshing method adapted to the gap is used and the finite difference method is used to discretize it.The node law of the gas film gap meshing of the bearing with gap is found and simulated by MATLAB programming to obtain the porous gas thrust.The static bearing characteristics of the bearing when passing through the gap of the air-floating platform are analyzed by simulation to analyze the influence of parameters such as different slot position,bearing radius and slot width on the static characteristics of the bearing.Based on the fractal theory,the tilt angle of the porous gas thrust bearing is analyzed and the influence of the tilt angle on the static bearing characteristics of the porous gas thrust bearing when passing through the gap is analyzed based on MATLAB simulation.The tilting of the bearing will make the distribution of the air gap uneven,which leads to the decline of static bearing capacity.Fractal theory is the main theory to analyze the bearing tilt problem.The theory analyzes the porous medium from the microscopic angle and determines the fractal dimension distribution vector through microscope observation.In turn,the magnitude and orientation of the bearing tilt angle are determined.The mathematical model of the over-slit of the porous gas thrust bearing is established,and the Reynolds equation of the bearing film gap is obtained.The MATLAB simulation is used to analyze the pressure distribution of the bearing film gap when the porous gas thrust bearing is over-slit.Impact and impact on the bearing's static bearing capacity.The experimental platform for the bearing performance of porous gas thrust bearing in over-slit condition was designed and built.The permeability test of porous gas bearing and the loading experiment of porous gas thrust bearing in different gap positions were carried out.The correctness of the mathematical modeling of the static bearing characteristics of the porous gas thrust bearing in the over-slit condition.