The exact analytical solution for the compressible two-dimensional gas flow in the microbearing is presented. The general slip-corrected Reynolds lubrication equation is derived and it is shown that it possesses an exact analytical solution. It is obtained by a suitable transformation of the independent variable, and it provides the pressure distribution in the bearing as well as the mass flow ...

We examine gas flow adjacent to a molecularly smooth, solid, muscovite mica. The fluctuations in force acting on a glass sphere as a function of proximity to a mica plate were measured in air and were used to obtain the damping. The damping was interpreted as a lubrication force. The measured damping as a function of separation in the slip-flow regime corresponds to a slip length of 480 ± 70 nm...

Over the last several decades, turbine efficiency has improved significantly, resulting in higher operating temperatures that negatively affect lubricating oil circulating through system. Exposure to high results degradation and eventual formation of solid deposits which greatly limit oil’s ability reduce wear cool components. An experimental apparatus was designed built allow for studying bett...

Turbo-expander is the most crucial and expensive component in Organic Rankine Cycle (ORC) power generation systems. The turbine engineering, design and research development process for ORC system is costly, time-consuming, and difficult for new-entrants in the ORC field. This paper investigates the re-design and retrofit of an off-the-shelf turbocharger for use in a 1 kW ORC system. The expande...

The stability of an evaporating thin liquid film on a solid substrate is investigated within lubrication theory. The heat flux due to evaporation induces thermal gradients; the generated Marangoni stresses are accounted for. Assuming the gas phase at rest, the dynamics of the vapour reduces to diffusion. The boundary condition at the interface couples transfer from the liquid to its vapour and ...

Abstract Porous gas bearings (PGBs) have a proactive application in aerospace and turbomachinery. This study investigates the lubrication performance of PGB with condition velocity slip boundary (VSB) owing to high Knudsen number film. The Darcy-Forchheimer laws modified Navier-Stokes equations were adopted describe flow porous layer film region, respectively. An improved bearing experimental p...

Increased machine efficiency is a requirement in today’s world and geared transmissions are no exception. A back-toback gear test rig was used to compare dip lubrication with spray lubrication regarding gearbox efficiency, mesh efficiency, gear temperature and surface roughness. Gears lubricated at the inlet of the mesh show a lower measured temperature when compared to spray lubrication at the...