Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Gases lubrication

Power requirements and discharge temperatures are calculated using the same relationships as used with the other rotary compressors already discussed. The efficiency is. 80 for air service and pressure in the 30 psig range. The mechanical losses are higher than the other rotaries. The mechanical loss is variable and dependent on gas, lubrication, and other factors. For an estimate, use. 15 of the gas horsepower. This approxuna tion should be close enough for an estimate. [Pg.128]

Mitsuya, Y, Modified Reynoids Equation for Uitra-Thin Fiim Gas Lubrication Using 1.5-Order Slip-Flow Model and Considering Surface Accommodation Coefficient," ASME J. Tri-bol, Voi. 115,1993, pp. 289-294. [Pg.5]

Meanwhile, study on ultra-thin film gas lubrication problems has become one of the most attractive subjects in the held of tribology during the past three decades. [Pg.96]

Historically, gas lubrication theory was developed from the classical liquid lubrication equation—Re5molds equation [4]. The first gas lubrication equation was derived by Harrison [5] in 1913, taking the compressibility of gases into account. Because the classical gas lubrication equation is based on the Navier-Stokes equation, it does not incorporate some gas flow characteristics rooted in the rarefaction effects of dilute gases. As early as 1959, Brunner s experiment [6] showed that the classical gas lubrication equation was... [Pg.96]

Since the middle of the 1990s, another computation method, direct simulation Monte Carlo (DSMC), has been employed in analysis of ultra-thin film gas lubrication problems [13-15]. DSMC is a particle-based simulation scheme suitable to treat rarefied gas flow problems. It was introduced by Bird [16] in the 1970s. It has been proven that a DSMC solution is an equivalent solution of the Boltzmann equation, and the method has been effectively used to solve gas flow problems in aerospace engineering. However, a disadvantageous feature of DSMC is heavy time consumption in computing, compared with the approach by solving the slip-flow or F-K models. This limits its application to two- or three-dimensional gas flow problems in microscale. In the... [Pg.96]

In most of the gas lubrication problems in nano-gaps, gas flow usually locates in the slip flow or the transient flow regime, depending on working conditions and local geometry. Therefore, both of the macroscopic and microscopic models are introduced to analyze the gas lubrication problems. [Pg.98]

Modified Reynolds Equations for Ultra-Thin Film Gas Lubrication... [Pg.98]

As described above, the magnitude of Knudsen number, Kn, or inverse Knudsen number, D, is of great significance for gas lubrication. From the definition of Kn in Eq (2), the local Knudsen number depends on the local mean free path of gas molecules,, and the local characteristic length, L, which is usually taken as the local gap width, h, in analysis of gas lubrication problems. From basic kinetic theory we know that the mean free path represents the average travel distance of a particle between two successive collisions, and if the gas is assumed to be consisted of hard sphere particles, the mean free path can be expressed as... [Pg.101]

The main task of head-disk gas lubrication analysis is to calculate the air pressure distributions for various known slider surface structures and given working conditions. In the following calculation examples, the modified Reynolds equation derived by Fukui and Kaneko was used, and the flow rate coefficient Qp was calculated by using the Eq (10). [Pg.105]

The last category is the pressure-driven gas flows, which are typical in micro gas fluidic and micro heat transfer systems. Because the channel diameter or width in micro gas fluidic systems is in the scale of sub-micrometer or less, ultra-thin gas lubrication theory plays an important role in... [Pg.114]

Burgdorfer, A., The Influence of the Molecular Mean Free Path on the Performance of Hydrodynamic Gas Lubricated Bearings,"ASMC/. Basic Eng., Vol. 81,1959, pp. 94-100. [Pg.114]

Hsia, Y. T. and Domoto, G. A., An Experimental Investigation of Molecular Rarefaction Effects in Gas Lubricated Bearings... [Pg.114]


See other pages where Gases lubrication is mentioned: [Pg.252]    [Pg.1009]    [Pg.1009]    [Pg.3]    [Pg.5]    [Pg.5]    [Pg.96]    [Pg.96]    [Pg.96]    [Pg.96]    [Pg.96]    [Pg.96]    [Pg.97]    [Pg.97]    [Pg.97]    [Pg.97]    [Pg.99]    [Pg.101]    [Pg.101]    [Pg.103]    [Pg.103]    [Pg.103]    [Pg.103]    [Pg.104]    [Pg.104]    [Pg.104]    [Pg.105]    [Pg.106]    [Pg.106]    [Pg.107]    [Pg.107]    [Pg.109]    [Pg.111]    [Pg.111]    [Pg.113]    [Pg.114]    [Pg.115]   
See also in sourсe #XX -- [ Pg.102 ]




SEARCH



Application of Gas Lubrication Theory

Gas lubrication in nano-gap

Gas lubrication theory

Gas turbine lubricants

Gas-Lubricated Bearings

Gas-phase lubrication, of MEMS devices

Gases as Lubricating Fluids

History of Gas Lubrication

Theory of Thin Film Gas Lubrication

© 2024 chempedia.info