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Show COLLEGE OF ENGINEERING UNDERGRADUATE RESEARCH AB TRACTS Mingfeng Qiu Bart Raeymaekers 24 THE EFFECT OF TEXTURE SHAPE ON THE STIFFNESS AND FRICTION COEFFICIENT OF GAS LUBRICATED PARALLEL SLIDER BEARINGS Bret Minson (Mingfeng Qiu, Bart Raeymaekers) Department of Mechanical Engineering University of Utah Surface texturing is used to increase hydrodynamic pressure and reduce friction and wear between gas lubricated parallel sliding surfaces. The shape, geometry, and density of the patterned microtexture features ("dimples") play a key role in the tribological performance of the textured slider bearings. The objective of this paper is to compare the stiffness and friction coefficient obtained with commonly used dimple shapes for gas lubricated textured parallel slider bearings. Six different texture shapes are considered, including spherical, ellipsoidal, circular, elliptical, triangular, and chevron-shaped dimples. The pressure distribution and load carrying capacity generated by different texture shapes are simulated using the compressible Reynolds equation over a domain containing a column often dimples. The texture geometry and density are optimized in terms of maximum bearing stiffness and minimum friction coefficient for each individual dimple shape, as a function of operating parameters such as relative velocity and spacing between the two sliding surfaces.The maximum bearing stiffness obtained with each individual texture shape - with optimized geometry and density - is then compared relative to each other. It is concluded that the ellipsoidal shape results in the highest bearing stiffness and minimum friction coefficeint, and the optimal geometry and density were found to be almost independent of the operating conditions. |
