Dynamic modeling and analysis of the different cavity-type hydrostatic slide turntable system
In this paper, a nonlinear oil-film force model with velocity term for hydrostatic slide system with rectangular, sector and round chamber is established respectively, by eliminating the small amount after the dimensional analysis with the help of Navier-Stokes equation, and combining with the oil-film bearing model of Hydrostatic Slide System of constant oil supply. And the turntable dynamic equations of hydrostatic slide system with different chambers are formulated consequently. Furthermore, the analysis of dynamics properties of the hydrostatic slide turntable with the same oil chamber area is investigated by numerical simulation. This research provide theoretical bases of the further studying and improving of the rest aspects property of hydrostatic oil film-turntable system.
FEA on the Oil Film of the Hydrostatic Slider
The design of hydrostatic slider was introduced.The pressure distribution of oil film in a hydrostatic slider was investigated.The mathematical equations of oil film pressure were deduced according to the hydro-lubrication theory and Reynolds equations.The analysis and calculating methods of the stiffness and the load capacity of oil film were presented by adopting the methods of finite element analysis(FEA).A practical sample was simulated with Marc.The contour band,curves of the pressure distribution with the load capacity and the stiffness of oil film were achieved.The numerical results indicate that it is accurate enough to meet the demand of the design.
Effects of reservoir volume on performance of pulse tube cooler.
A pulse tube cooler has the advantages of long-life and low-vibration over conventional cryocoolers such as G-M and Stirling coolers because of the absence of moving parts at low temperature. On the other hand, the combination of a reservoir and orifice is indispensable to optimize the performance of pulse tube coolers. In order to make the pulse tube cooler compact for practical applications, the volume of reservoir should be minimized. This paper analyzes the effects of the reservoir volume on the thermodynamic performance of various components in a simple orifice and a double-inlet pulse tube cooler by combining a linearized model with a thermodynamic analysis. Expressions of entropy production for those components are presented. The results show that the reservoir volume has a significant influence on the entropy production in the various components when the reservoir to pulse tube volume ratio is smaller than about 5. The ratio is important to determine the minimum reservoir volume for a pulse tube cooler. Optimum settings for a double-inlet pulse tube cooler are also discussed.