Closure to “Discussion of ‘Application of Average Flow Model to Lubrication Between Rough Sliding Surfaces’” (1978, ASME J. Lubr. Technol., 101, pp. 229–230)

The influence of operating and design parameters on the magnetic tape/guide friction coefficient

“…The parameter a represents the spacing at which head/tape contact begins. Hence, according to [10], a is equivalent to 3r s in our model. The parameter b represents the pressure required to force zero spacing between the head and the tape.…”

“…In the case of rough surfaces, the mean through the surface is generally used to denote the effective spacing. Alternatively, Patir and Cheng [10] introduced averaging procedures ending in pressure flow and shear flow terms. Lacey and Talke [9] presented an empirical expression relating the load carried by contacting asperities to the spacing at the head/tape interface.…”

“…As shown in figure 1(b), the angular coordinate is denoted by a and the wrap angle by h. The tape tension results in a normal load, which is partially supported by the air bearing pressure and partially by asperity contact. It is justifiable to assume that contacts between tape and guide are absent if the spacing h ‡3r s , where r s is the standard deviation of asperity summit heights distribution [10].…”

The Effect of Triangular Dimple Orientation on Load-Carrying Capacity

“…The hydrodynamic pressure can be solved by the Reynolds equation. According to the average flow model proposed by Patir and Cheng [20][21], the Reynolds equation which satisfies the mass conservation can be written in the Cartesian coordinate in the following: 3 3 12 12…”

Effects of the Tilting Guide Rail on the Bearing Capacity of the Hydrostatic Circular Pads

“…The basic design guidance of hydrostatic bearing performance for different pad geometries has been proposed by Fuller [1], Rippel [2], and Rowe [3].Further researches of hydrostatic thrust bearings with various operating situations have also been carried out, such as turbulent lubrication by Khalil and Ismail [4], selection of parameters for minimum power and low temperature rise by Rowe et al [5], optimization of bearing stiffness by Ling [6], and dynamic stiffness and damping behaviors by Ghosh and Majumdar [7].All the above studies focus upon the performance characteristics of hydrostatic thrust bearings with the ideal assumption that bearing surfaces are perfectly smooth. Patir and Cheng [8,9] developed an average flow model of a randomly generated rough surface with known statistical properties over the surface area. In this model, the actual flow between rough bearing surfaces is equated to an averaged flow between nominally smooth bearing surfaces.…”