We compared three different tracheal wall pressure measuring techniques in vitro. Using a high-volume, low-pressure, cuffed tracheal tube with an internal diameter of 7.5 mm and a model trachea, the pressure difference technique, the wall pressure membrane technique and the microchip sensor probe technique with and without lubrication were studied. Wall pressures were measured after sequential ...

A nonlocal diffuse interface model is explored using the "lubrication approximation" applicable to thin films. We show the inconsistency of the expansion leading to a nonlinear diffusion model, and solve an untruncated integro-differential mean field equation to compute the equilibrium density profile across the fluid-vapor interface. The disjoining potential and effect of interfacial curvature...

In this study, in order to investigate the lubrication characteristics of the sliding surface of the vane in a rotary compressor, numerical analysis for mixed lubrication has been developed. In this analysis, the modified Reynolds equation and the elastic contact equation, considering the surface roughness, are solved as a coupled problem. Using this analysis, the lubrication characteristics of...

The failure reasons of reciprocating sealing in OPI-1800AWS fracturing pump are analyzed by scanning electron microscope technology (SEMT). The lubrication mechanism of plunger seal friction pair is analyzed by hydrodynamic lubrication theory. During its discharge and suction stroke, the reciprocating sealing friction pair meets the conditions of hydrodynamic lubrication, a certain thickness of...

The primary objective of this study was to compare the lubrication properties of micronized poloxamer 188 (Lmicrotrol micro 68) and micronized poloxamer 407 (Lmicrotrol micro 127) with certain conventional lubricants such as magnesium stearate and stearic acid. The secondary objective was to use these micronized poloxamers as water-soluble tablet lubricants in preparation of effervecsent tablet...

Many studies have already considered starved lubrication. However, there have been no reports on the oil film thicknesses under steady starved EHL (elastohydrodynamic lubrication), where the ultra-low volume of oil supplied per unit time is uniform. The present study examined the relationship between the supplied oil flow rate and oil film thickness under steady starved lubrication. A ball-on-d...

The friction pair of piston rings and cylinder liner is one of the most important friction couplings in an internal combustion engine. It influences engine efficiency and service life. Under the excitation of piston slaps, the dynamic deformation of cylinder liner is close to the surface roughness magnitudes, which can affect the friction and lubrication performance between the piston rings and...

We present a collision model for particle-particle and particle-wall interactions in interface-resolved simulations of particle-laden flows. Three types of interparticle interactions are taken into account: (1) long- and (2) short-range hydrodynamic interactions, and (3) solid-solid contact. Long-range interactions are incorporated through an efficient and second-order-accurate immersed boundar...

The effects of surface texture on the lubrication performance of a compression ring-cylinder liner system are studied in this paper. By considering the surface roughness of the compression ring and cylinder liner, a mixed lubrication model is presented to investigate the tribological behaviors of a barrel-shaped compression ring-cylinder liner system with spherical dimples on the liner. In orde...

FIG. 1 Proposed mechanisms of joint lubrication (Redrawn after Walker and others, 1968) (Lancet, 1969; Dowson, Wright, and Longfield, 1969) and a further possibility, 'weeping' lubrication, has been proposed (McCutchen, 1959, 1962). More recently, the role ofelectrostatic forces at articulating surfaces has been investigated (Roberts, 1971). In each of these hypothetical mechanisms the thesis h...