Research on Face Fluid Field and Seal Performance of T-shape Groove Dry Gas Seal
To obtain more details about the fluid field and high stability of dry gas seal, according to Reynolds equation of compressible perfect gas, on isothermal condition, the controlling equation of gas between the T-shape groove dry gas seal faces is established, and the controlling equation is converted into a non-dimensional equation. The gas flow capacity of T-shape groove dry gas seal is reached with computer simulation in Fluent software, on the basis of numerical simulation, the working parameters (such as, rotating speed, pressure, viscosity of medium, etc.) and the geometric parameters (such as, groove number, groove deep, groove width ratio, balance clearance, etc.) which affect seal performance, are discussed in detail, and the affecting curves are gained. The parameters ( such as, groove deep, balance clearance) which affect seal performance mostly should be chosen correctly in design. The general principle for selecting geometric parameters and working parameters of T-shape groove dry gas seal are obtained, for example, the groove number should be chosen within 12¿16, the groove deep should be chosen within 4¿6 μm, the balance clearance should be chosen within 0.8¿1.4 μm. It offers theoretical support for engineering design and application of T-shape groove dry gas seal.
Effects of parameters of spiral groove gas face seals on seal performance
The influences of the spiral groove parameters on the opening force, power loss, leakage rate and stiffness of gas film were investigated by the experimental test. The obtained data were compared with the results from theoretical calculation. In general, α g and β have big effect on the seal performance, but N g, α g, l and P r have small effect on it. The recommended geometric parameters are presented(12 N g18,14° β 16°, 0 4 α g0 6,0 3 l 0 5,1 6 δ 1 8,10 P r20).
Researches on Structural Factor Involvement in Oral Tribology
This study is focused on two ceramic materials, D.SING (Ivoclar) and VM13 (emphasis the VITA TN), frequently used in restorative dentistry practice and it comes to complete a full set of results obtained by the authors over several years of research on oral tribology with main influence on oral health. In this way there are involved more specific structural aspects of dental restorative ceramic materials quality as is shown in [1].