The definition of air resistance is nonuniform when analyzing the bearing capacity, stiffness, and stability of an orifice throttling aerostatic restrictor. In this study, a capillary tube similar to the inlet section of an aerostatic restrictor is used as the research object, and the Bernoulli equation under adiabatic conditions is established. Through an experiment, the pressure and temperature of the capillary tube inlet and outlet and the flow through the capillary tube are measured. Based on the air resistance definition, the empirical formula of the coefficient k is obtained, and the theoretical air resistance of the capillary path is calculated. The relative error between the theoretical air resistance and experimental air resistance is kept within 10%. The comparison results verify the accuracy of the air resistance theory and provide a basis for the subsequent establishment of a universal definition of air resistance. Subsequently, air resistance can be used to design aerostatic bearings and help improve their characteristics.

Herein, a processing method is proposed for accurate microdisplacement measurements from a 2D Fabry–Perot (F-P) fringe pattern. The core of the processing algorithm uses the F-P interference imaging concentric ring pattern to accurately calculate the centre coordinates of the concentric ring. The influencing factors of measurement were analysed, and the basic idea of data processing was provided. In particular, the coordinate rotation by the 45-degree method (CR) was improved; consequently, the virtual pixel interval was reduced by half, and the calculation accuracy of the circle centre coordinate was improved. Experiments were conducted to analyse the influence of the subdivision and circle fitting methods. The results show that the proposed secondary coordinate rotation (SCR) by 45 degrees method can obtain higher accuracy of the centre coordinate than the CR method, and that the multichord averaging method (MCAM) is more suitable for calculation of the centre coordinate than the circular regression method (CRM). Displacement measurement experiments were performed. The results show that the standard experimental deviation of the centre of the circle is approximately 0.009 µm, and the extended uncertainty of the displacement measurement in the range of 5 mm is approximately 0.03 μm. The data processing method studied in this study can be widely used in the field of F-P interferometry.

When a restrictor is coupled with groove microstructures, the analysis on the flow-field status of the restrictor’s lubricating gas film becomes more difficult, especially in theoretical calculation. In this study, a single-orifice planar restrictor with double-ring-grooves was researched. First, the theoretical mathematical analysis and calculation of the pressure and temperature distributions of the lubricating gas film, were conducted based on the proposed analysis method of proportional assignation and resynthesis (PAR) along with the finite difference method. Then, the computational fluid dynamics (CFD) simulations based on the simple model were conducted, the results of which show the agreement with the theoretical analysis. Finally and more importantly, experiments were carried out well by using a self-made micro-flow field parameter measurement device (MFFPMD), which verifies the theoretical calculation and the CFD simulation results. The PAR method can be applied in other structures of restrictors, and the experimental study could facilitate the research of the stability of the lubricating gas film.

Aiming at the problem of energy utilization problems in aerostatic lubrication technology, the energy efficiency of aerostatic restrictor is established as `the ratio of air flotaion work to compression energy', and a mathematical model of energy efficiency is derived. This paper studies energy efficiency testing methods, designs an energy efficiency testing device, and conducts a multi-parameter energy efficiency testing experiment. It shows that the energy efficiency value of the restrictor can effectively obtained by testing method; the maximum energy efficiency of operating conditions are the intake pressure is 0.3MPa and the inner diameter of the intake pipe is 2mm. It also shows that the energy efficiency of the device is positively related to the bearing capacity, and inversely related to the supply pressure, intake flow and air film thickness; and to a certain extent, energy efficiency is positively correlated with the working area of aerostatic restrictor.

Slide stability is key to the aerostatic guide in ultra-precise machines; thus, it has garnered plenty of attention. Macro-scale studies are commonplace, but micro- and nano-vibration issues require more attention. Microscope vibration is mainly caused by tiny changes in the fluid parameters of lubricating gas film, which is complex and has no verdict. In this case, slide-gas interaction should be considered. In this study, the widely used orifice-type restrictor was investigated for its nano-vibration performance. A Comsol finite-element-method fluid–structure interaction model was used to simulate and analyze an orifice-type restrictor, and orifice-restrictor vibration characteristics at the nanometer scale were inspected using a high-performance laser vibrometer. The results demonstrate that see-saw mode vibrations occur in the restrictors, growing stronger with increased air-supply pressure. The see-saw vibration’s axis is speculatively determined based on orifice and restrictor structures, and the vibration type is related to the number of orifices. The results also show that the vibration is random with natural frequencies at the kilohertz level. The newly provided research results are beneficial for better understanding the nano-vibrations of orifice-type restrictors.

The principle of electro-analogy analysis treats a gas path structure as analogous to a circuit, offering significant potential for performance analysis in aerostatic systems. However, research on gas resistance remains in an early stage. This study investigates pipe gas resistance and its series characteristics using a slender circular pipe as the subject. First, gas resistance is redefined based on a derivation of the Bernoulli equation, resulting in formulas covering low and high speeds and a calculation model for series gas resistance. Simulations are conducted to model the pipe, focusing on the coefficient of frictional resistance at low speeds. The results provide insights into the gas resistance of pipes with varying inner diameters and related series connections. An experiment is conducted to validate predictions, indicating that, at low speeds, the defined and determined gas resistance values for pipelines with inner diameters ranging from 1 to 6 mm are largely consistent. Both gas and series gas resistances decrease as the pressure difference between the two pipe ends increases. Relative errors below 5% are typically regarded as very good, especially when dealing with complex systems. The maximum relative error between the experimentally measured single gas resistance, based on the defining formula and the simulation value, is 3.1%. Furthermore, the maximum relative errors for the measured single and series gas resistance values are 5% and 3.8%, respectively, according to the defining and determining formulas. The theoretical model is effective and reliable, providing valuable theoretical support for impedance analysis of aerostatic systems.