...Donghyun Lee; Daejong Kim A new thermohydrodynamic analysis model for bump air foil bearings with a detailed thermal model of bump foil structures and rotor is presented. In the developed model, temperatures of lubricating air film, top foil, bump foils, bearing sleeve, and rotor are calculated...

...Tae Ho Kim; Luis San Andrés An engineered thermal management is fundamental to the application of gas foil bearings (GFBs) as turboshaft supports in rotorcraft propulsion systems. The paper presents a model for the thermal energy transport in a rotor-GFB system operating at high temperature...

...Tae Ho Kim; Anthony W. Breedlove; Luis San Andrés Oil-free turbomachinery relies on gas bearing supports for reduced power losses and enhanced rotordynamic stability. Gas foil bearings (GFBs) with bump-strip compliant layers can sustain large loads, both static and dynamic, and provide damping...

..., this work considered the storage device to utilize a 1 in. titanium foil disk and a pair of opposed femtosized zero-load recording head sliders with asymmetrically configured air bearing surfaces. A titanium foil disk, due to its reduced thickness and relatively low mass density, requires less operational...

...Dong-Hyun Lee; Young-Cheol Kim; Kyung-Woong Kim To obtain the foil bearing characteristics, the fluid film pressure must be coupled with the elastic deformation of the foil structure. However, all of the structural models thus far have simplified the foil structure without consideration of its...

...Daejong Kim Experimental and analytical studies on air foil bearings have been performed extensively over the past decades, and significant improvement in load capacity and rotor dynamics stability have been reported. Often, advanced air foil bearings are believed to have complicated bump foil...

...Sébastien Le Lez; Mihai Arghir; Jean Frene The performance of gas foil bearings (GFBs) relies on a coupling between a thin gas film and an elastic structure with dissipative characteristics. Because of the mechanical complexity of the structure, the evaluation of its stiffness and damping is still...

...Tae Ho Kim; Luis San Andrés Commercial oil-free microturbomachinery implements gas foil bearings (GFBs) for reliable performance with improved efficiency. However, GFB modeling is still largely empirical, lacking experimental validation. An analysis of simple GFBs operating at large shaft speeds...

...Z.-C. Peng; M. M. Khonsari A model is developed to predict the hydrodynamic performance of a foil journal bearing. The model accounts for both the compressibility of air and the compliance of the bearing surface. A series of predictions of the load-carrying capacity based on the numerical solution...

...Christopher DellaCorte; Antonio R. Zaldana; Kevin C. Radil Foil air bearings are self-acting hydrodynamic bearings which rely upon solid lubricants to reduce friction and minimize wear during sliding which occurs at start-up and shut-down when surface speeds are too low to allow the formation...

... characteristics to achieve the desired stable and low vibration operation. Building upon the technology of thin metallic corrugated bump foils presently used in a particular class of film riding hydrodynamic bearings, a novel corrugated bump foil damped mount is introduced which provides stiffness and damping...

...HR Le; M. P. F. Sutcliffe A mechanical model of cold rolling of foil is coupled with a sophisticated tribological model. The tribological model treats the “mixed” lubrication regime of practical interest, in which there is “real” contact between the roll and strip as well as pressurized oil between...

...Hooshang Heshmat, Fellow ASME A series of experiments were conducted to determine a foil bearings ability to operate in the region of the bending mode of a flexible rotor. Three different bearings, spaced at three different positions along the shaft, were tested in order to make super-bending...

...Crystal A. Heshmat; David S. Xu; Hooshang Heshmat Load performance of gas lubricated, compliant surface foil thrust bearings has an interlocking relationship with the compliance of the bearing and hydrodynamics of convergent wedge surface. Compliance of the bearing consists of supporting spring...