3D Numerical investigation of pressure field of an orifice compensated hydrostatic bearing

Abstract

In recent years, much attention has been given to hydrostatic/hybrid journal bearings in research due to their wide spread engineering applications, such as: high speed turbomachinery, machine tools spindles, cryogenic equipment, and precision grinding. However, the activity toward improved understanding of the flow regimes and the associated pressure pattern in the recess flow phenomena is still needed. The objective of this work is to provide an understanding of the influence of regime flow in recess on the pressure field of hydrostatic bearing flat pad fed by orifice restrictor and orifice inertia. 3D Reynolds averaged Navier Stokes equations with the SST-kω turbulence model are applied in order to investigate the effects of pressure supply, dynamic viscosity and recess depths on the pressure profile. The finite volume method implemented in the ANSYS-CFX software is used. To prove the robustness of CFD code, a comparison of the numerical results and the Reynolds equation is performed at very deep recess. The results exhibit very good agreements between CFD and Reynolds equation methods. On the other hand, the several cases treated in this work contribute also to analyze and to explain the main reasons providing the inertia and the Rayleigh effect in recess flow.

CFD-Based Investigation on Effects of Orifice Length–Diameter Ratio for the Design of Hydrostatic Thrust Bearings

“…It had been verified that the CFD simulation method was an effective means to accurately analyze the fluid characteristics of hydrostatic bearings [13,[22][23][24][25]. Hence, the CFD simulation method is employed to investigate the effects of varied OLDRs on the performance of the hydrostatic thrust bearing.…”

“…Orifice restrictors, which are very compact devices, are most commonly restrictors for hydrostatic bearings because of simple manufacturing [11][12][13][14]. Sharma et al analyzed the influence of wear on the performance of a four-pocket hybrid conical journal bearing compensated with an orifice restrictor of which the length-diameter ratio was more than 2.5 [15].…”

Pressure distribution in orifice-compensated turbulent hydrostatic bearing with fluid inertia effects using numerical simulations via Navier-Stokes

“…The fast change in the interior system volume caused by the high acceleration cannot be compensated by the It is already possible to predict some pressure patterns mentioned by other authors. For example, the peak and the sudden decrease of the pressure at the centre of the recess and near its boundaries [16], are clearly consequences of the fluid jet at the centre of the recess and the recirculation zone, respectively, (Figure 8).…”

Assembly Error Tolerance Estimation for Large-Scale Hydrostatic Bearing Segmented Sliders under Static and Low-Speed Conditions

“…They also serve as a safety element that helps to align the surfaces using the pressure difference they generate. There are various types, from basic, such as orifice (see [19,20] or [21]), to more sophisticated, including membranes [22] or controllable elements, such as electromagnetic valves [23,24]. Previous research aimed to compensate for pad misalignment using compliant support numerically [25,26] and experimentally [27], respectively.…”