This paper shows the mixed lubrication analysis between the vane tip and rolling piston in a rotary refrigerant compressor, coupling the motion equations of vane and rolling piston, the elastohydrodynamic lubrication (EHL) analysis of line contact and the equations of viscosity characteristics of lubricating oil as a function of oil pressure, oil temperature and concentration of refrigerant. Th...

Piston scuffing is one of the destructive faults in internal combustion (IC) engines. There are different causes to make this fault that lack of lubricant is the most important one among them. The purpose of this paper is the quantitative study of the piston scuffing effects on the engine performance parameters which is a new research direction in the IC engine filed. For this reason, several e...

OBJECTIVE To evaluate the effect of piston diameter in primary stapedotomy for otosclerosis patients measured by hearing outcome. DATA SOURCES PubMed, Embase, and the Cochrane Library. REVIEW METHODS A systematic search was conducted. Studies reporting original data on the effect of piston diameter on pure-tone audiometric results in patients undergoing primary stapedotomy for otosclerosis ...

We provide a completely new perspective for the analysis of Casimir forces in very general piston configurations. To this end, in order to be self-contained, we prove a “gluing formula” well known in mathematics and relate it with Casimir forces in piston configurations. At the center of our description is the Dirichlet-to-Neumann operator, which encodes all the information about those forces. ...

This study investigated the relationship between the pinch-off of axisymmetric vortex rings and the evolution of pressure in the shear layer being entrained into the vortex rings. A piston-cylinder apparatus was used to generate the vortex rings, and five cases of constant piston acceleration over distances ranging from zero (impulsive start) to eight piston diameters were investigated. It was ...

The compression chamber of a hermetic reciprocating compressor is, normally, formed by a cylinder and a piston which present a constant clearance during the piston displacement inside the compression chamber. This configuration has the advantage of a good sealing, however, during the most part of compression, the pressure difference between compression chamber and internal compressor ambient is...

In the paper a comprehensive model of a piston ring pack motion on an oil film has been presented. The local oil film thickness can be compared to height of the combined roughness of sliding surfaces of piston rings and cylinder liner. Equations describing the mixed lubrication problem based on the empirical mathematical model formulated in works of Patir, Cheng and Greenwood, Tripp have been c...

Does it feel the same when you touch an object in Augmented Reality (AR) or in Virtual Reality (VR)? In this paper we study and compare the haptic perception of stiffness of a virtual object in two situations: (1) a purely virtual environment versus (2) a real and augmented environment. We have designed an experimental setup based on a Microsoft HoloLens and a haptic force-feedback device, enab...

With the aim of developing a method for reducing energy consumption of room air conditioners, we address a higher-efficiency design of the rotary compressor currently most used worldwide. We focused on a new rotary compressor equipped with a mechanism to restrict the rolling motion of the piston, and performed a dynamics analysis. The new rotary compressor has a small pillar at the tip of the v...

introduction:different types of prosthesis are available for stapes replacement. because there has been no published report on the efficacy of the titanium soft-clip vs the fluoroplastic causse loop teflon piston, we compared short-term hearing results of both types of prosthesis in patients who underwent stapedotomy due to otosclerosis.materials and methods:a total of 57 ears were included in ...