Investigations on characteristics of micro/meso scale gas foil journal bearings for 100–200 W class micro power systems using first order slip velocity boundary conditions and the effective viscosity model

被引：0
作者：
Skylab P. Bhore
Ashish K. Darpe
机构：
[1] Indian Institute of Technology Delhi,Department of Mechanical Engineering
来源：
Microsystem Technologies | 2013年 / 19卷
关键词：
Attitude Angle; Effective Viscosity; Rotor Bear System; Eccentricity Ratio; Rarefaction Effect;
D O I：
暂无
中图分类号：
学科分类号：
摘要：
In this paper, a modified compressible Reynolds equation for micro/meso scale gas foil journal bearings considering first order slip and effective viscosity under rarefied flow conditions is presented. The influence of rarefaction effect on the load carrying capacity, attitude angle, speed and frequency dependent stiffness and damping coefficients, modal impedance, natural frequencies and unbalance response is studied. From numerical analysis, it has been found that there is significant change in all the static and dynamic characteristics predicted by the no-slip model and model with effective viscosity. There is also a considerable difference between the values predicted by a model with effective viscosity and a model without effective viscosity. For a given eccentricity ratio, the influence of effective viscosity on load carrying capacity and attitude angle is more significant for the typical operating speed range of micro/meso scale gas turbines. The influence of effective viscosity decreases with increase in compliance of bearing structure. Similarly, the influence of effective viscosity on frequency dependent stiffness and damping coefficients increases with excitation frequency ratio. Significant change in natural frequency, modal impedance and unbalance response for model with no slip and slip with effective viscosity is observed. The influence of effective viscosity is found to be significant with increase in Knudsen number.
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页码：509 / 523
页数：14
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  • [1] Burgdorfer A(1959)The influence of the molecular mean free path on the performance of hydrodynamic gas lubricated bearings ASME J Basic Eng 81 94-100
  • [2] Chan W(2003)Analytical modeling of ultra-thin film bearings IEEE J Micromech Microeng 13 463-473
  • [3] Sun Y(1988)Analysis of ultra-thin gas film lubrication based on linearized Boltzmann equation: first report-derivation of generalized lubrication equation including thermal creep flow ASME J Tribol 110 253-262
  • [4] Fukui S(1983)Analysis of gas lubricated foil journal bearings ASME J Lubr Technol 105 647-655
  • [5] Kaneko R(2005)Development of high-speed micro-gas bearings for three-dimensional micro-turbo machines IOP J Micromech Microeng 15 S222-S227
  • [6] Heshmat H(2006)Experimental verification of the feasibility of a 100 W class micro- scale gas turbine at an impeller diameter of 10 mm IOP J Micromech Microeng 16 S254-S261
  • [7] Walowit JA(2007)Parametric studies on static and dynamic performance of air foil bearings with different top foil geometries and bump stiffness distributions ASME J Tribol 129 354-364
  • [8] Pinkus O(2008)Heavily loaded gas foil bearings: a model anchored to test data ASME J Eng Gas Turbines Power 130 1-8
  • [9] Isomura K(2009)Mesoscale foil gas bearings for palm sized turbomachinery: design, manufacturing and modeling ASME J Eng Gas Turbines Power 131 1-10
  • [10] Tanaka S(2002)The influence of the slip flow on steady-state load capacity, stiffness and damping coefficients of elastically supported gas foil bearings STLE Tribol Trans 45 478-484
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