Parameter sensitivity analysis on dynamic coefficients of partial arc annular-thrust aerostatic porous journal bearings | |
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Year of publication | 2021 |
Title of paper | Parameter sensitivity analysis on dynamic coefficients of partial arc annular-thrust aerostatic porous journal bearings |
Authors | Hwang, P., Khan, P., and Kang, S.-W. |
Volume | 11(22) |
Pages | 10791 - 1 - 17 |
Journal | Applied Sciences (2020 I.F. = 2.697) |
Link | https://doi.org/10.3390/app112210791 214회 연결 |
Aerostatic bearings are widely used in high‐precision devices. Partial arc annular‐thrust aerostatic porous journal bearings are a prominent type of aerostatic bearings, which carry both radial and axial loads and provide high load‐carrying capacity, low air consumption, and relatively low cost. Spindle shaft tilting is a resource‐demanding challenge in numerical modeling because it involves a 3D air flow. In this study, the air flow problem was solved using a COMSOL software, and the dynamic coefficients for tilting degrees of freedom were obtained using finite differences. The obtained results exhibit significant coupling between the tilting motion in the x‐and y‐directions: cross‐coupled coefficients can achieve 20% of the direct coefficient for stiffness and 50% for damping. In addition, a nonlinear behavior can be expected, because the tilting motion within 3°, tilting velocities within 0.0012°/s, and relative eccentricity of 0.2 have effects as large as 20% for direct stiffness and 100% for cross‐coupled stiffness and damping. All dynamic coefficients were fitted with a polynomial of eccentricity, tilting, and tilting velocities in two directions, with a total of six parameters. The resulting fitting coefficient tables can be employed for the fast dynamic simulation of the rotor shaft carried on the proposed bearing type. |