Hydrostatic guideways are widely used in precision and ultra-precision machine tools due to their high load-carrying capacity, stiffness, and superior vibration isolation capabilities. This study presents a comprehensive computational fluid dynamics (CFD) investigation of the influence of different recess shapes and restrictor types on the key performance indicators of hydrostatic guideways. A three-dimensional CFD model is developed using ANSYS Fluent to simulate lubricant flow through the restrictor, recess, and land regions under steady-state operating conditions. Multiple recess geometries are analysed while maintaining a constant recess-to-land area ratio, and both capillary and orifice restrictors are modelled with appropriate flow characteristics. The performance of the hydrostatic pad is evaluated in terms of recess pressure, load- carrying capacity, stiffness, and mass flow rate over a range of operating fluid film thicknesses. The results indicate that recess geometry has a significant impact on pressure uniformity and load distribution, while the restrictor type plays a dominant role in overall performance. Orifice restrictors consistently exhibit higher load-carrying capacity and reduced mass flow rate compared to capillary restrictors, indicating improved hydraulic efficiency. The findings provide practical design insights for optimizing hydrostatic guideways in high-precision manufacturing and advanced machine tool applications.

Furthermore, the analysis reveals that specific recess configurations minimize flow recirculation zones, thereby stabilizing the fluid film pressure profile. This stabilization is critical for reducing micro-vibrations during machining processes. The study highlights that while capillary restrictors offer linear flow characteristics, the non-linear behaviour of orifice restrictors provides superior stiffness compensation under varying loads. Consequently, selecting an optimal recess shape with an orifice restrictor enhances damping characteristics, leading to superior surface finish quality. These numerical predictions enable designers to balance hydraulic power consumption with mechanical stability, facilitating the development of energy-efficient machine tools capable of achieving nanometric positioning accuracy in challenging, dynamic environments.