Showing papers by "Scott Bair published in 1997"

A Simple Formula for EHD Film Thickness of Non-Newtonian Liquids

Abstract: The classical EHD numerical solutions have provided the machine designer with simplified formulae for prediction of concentrated contact film thickness when the lubricant is Newtonian. Many liquids which function as lubricants display non-linear shear response in the range of shear stress critical to the pressure boosting zone of a concentrated contact. A recently developed numerical scheme for incompressible, isothermal line contact is used with a simplified rheological model to obtain a film thickness correction formula for non-Newtonian liquids using a minimum of parameters. The resulting prediction is compared with experiment.

Hydrojet apparatus for refractive surgery

Abstract: An apparatus for supporting and guiding the movement of a high speed liquid jet for ophthalmic incisions includes a fixture (12) for removably securing the device with respect to the apex of the cornea (17). The corneal apex (17) extends through an opening (24) in the fixture (12), and a concentric suction ring (13) secures the fixture (12) to the eyeball. A proximal portion of the fixture (12) is provided with an internal cutout to permit resilient horizontal flexure of the proximal portion (23). A first linear actuator is arranged to drive the first flexible bracket (23) to translate horizontally in precisely controlled motion. Joined orthogonally to the fixture (12) is a second flexible bracket (31) having an internal cutout that permits resilient vertical flexure. One end of the second flexible bracket (31) is secured rigidly to the fixture (12), and a micrometer actuator is joined to the movable end of the second flexible bracket (31) to position it vertically in precisely controlled spacing.