Granular Collision Lubrication: Experimental Investigation and Comparison to Theory

An experimental investigation of the friction and lift characteristics of granular lubrication is presented. Experiments are carried out to demonstrate the vertical displacement (lift) observed in an annular shear cell apparatus. Results are presented for the friction coefficient as a function of the rotational speed and the applied load for several surface roughness combinations. Simulations of the kinetic theory for the granular material are performed and compared to the experimental results. The experiments provide an evidence for the formation of granular lift between two disks undergoing sliding motion.

[1]  H. Heshmat,et al.  100mm Diameter Self-Contained Solid/Powder Lubricated Auxiliary Bearing Operated at 30,000 rpm , 2002 .

[2]  J. Tichy,et al.  Granular collisional lubrication : Effect of surface roughness, particle size and solids fraction , 1996 .

[3]  M. Khonsari,et al.  On the granular lubrication theory , 2005, Proceedings of the Royal Society A.

[4]  J. E. Ungar,et al.  Boundary conditions for high-shear grain flows , 1984, Journal of Fluid Mechanics.

[5]  Michael M. Khonsari,et al.  Granular Lubrication: Toward an Understanding of the Transition Between Kinetic and Quasi-Fluid Regime , 2004 .

[6]  S. Savage,et al.  Stresses developed by dry cohesionless granular materials sheared in an annular shear cell , 1984, Journal of Fluid Mechanics.

[7]  R. Jackson,et al.  Frictional–collisional constitutive relations for granular materials, with application to plane shearing , 1987, Journal of Fluid Mechanics.

[8]  C. Higgs,et al.  Granular Flow Lubrication: Continuum Modeling of Shear Behavior , 2004 .

[9]  M. Khonsari,et al.  Flow Characterization and Performance of a Powder Lubricated Slider Bearing , 2003 .

[10]  Michael M. Khonsari,et al.  Generalized Boundary Interactions for Powder Lubricated Couette Flows , 1996 .

[11]  T. Blanchet,et al.  Serum Lubricant Absorption by UHMWPE Orthopaedic Bearing Implants , 2002 .

[12]  H. Elrod.  Paper IV(i) Granular flow as a tribological mechanism – a first look , 1987 .

[13]  H. Heshmat,et al.  The quasi-hydrodynamic mechanism of powder lubrication. Part II: Lubricant film pressure profile , 1992 .

[14]  On the Lubrication Mechanism of Grain Flows , 1994 .

[15]  Yeau-Ren Jeng,et al.  CHARACTERISTICS OF POWDER LUBRICATED FINITE-WIDTH JOURNAL BEARINGS: A HYDRODYNAMIC ANALYSIS , 2006 .

[16]  M. Khonsari.  On the modeling of multi-body interaction problems in tribology , 1997 .

[17]  C. Campbell.  Boundary interactions for two-dimensional granular flows. Part 1. Flat boundaries, asymmetric stresses and couple stresses , 1993, Journal of Fluid Mechanics.

[18]  K. Craig,et al.  Granular collision lubrication , 1994 .

[19]  Karen Mair,et al.  Influence of grain characteristics on the friction of granular shear zones , 2002 .

[20]  Venkata K. Jasti,et al.  A Review of Dry Particulate Lubrication: Powder and Granular Materials , 2006 .

[21]  P. Haff.  Grain flow as a fluid-mechanical phenomenon , 1983, Journal of Fluid Mechanics.

[22]  R. Bagnold.  Experiments on a gravity-free dispersion of large solid spheres in a Newtonian fluid under shear , 1954, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[23]  Effect of Shear Surface Boundaries on Stress for Shearing Flow of Dry Metal Powders—An Experimental Study , 1987 .

[24]  D. Jeffrey,et al.  Kinetic theories for granular flow: inelastic particles in Couette flow and slightly inelastic particles in a general flowfield , 1984, Journal of Fluid Mechanics.

[25]  Arshad Kudrolli,et al.  Cluster formation due to collisions in granular material , 1997 .

[26]  D. Inman,et al.  Observations of rapidly flowing granular-fluid materials , 1985, Journal of Fluid Mechanics.

[27]  Dong F. Wang,et al.  Humidity effect on the critical number of friction cycles for wear particle generation in carbon nitride coatings , 2003 .

[28]  J. Jenkins,et al.  Boundary conditions for plane flows of smooth, nearly elastic, circular disks , 1986, Journal of Fluid Mechanics.

[29]  H. Heshmat.  High-temperature solid-lubricated bearing development - Dry powder-lubricated traction testing , 1991 .

[30]  Ali Hassanpour,et al.  Shear deformation of binary mixtures of dry particulate solids , 2004 .

[31]  Charles S. Campbell,et al.  Boundary interactions for two-dimensional granular flows. Part 2. Roughened boundaries , 1993, Journal of Fluid Mechanics.

[32]  Yves Berthier,et al.  Solid Third Body Analysis Using a Discrete Approach: Influence of Adhesion and Particle Size on Macroscopic Properties , 2002 .

[33]  H. Heshmat,et al.  Performance of Powder-Lubricated Journal Bearings With MoS2 Powder: Experimental Study of Thermal Phenomena , 1995 .

[34]  O. Reynolds.  IV. On the theory of lubrication and its application to Mr. Beauchamp tower’s experiments, including an experimental determination of the viscosity of olive oil , 1886, Philosophical Transactions of the Royal Society of London.

[35]  M. Khonsari,et al.  Flow Characteristics of a Powder Lubricant Sheared Between Parallel Plates , 2000 .

[36]  W. Gregory Sawyer,et al.  Lubrication With Granular Flow: Continuum Theory, Particle Simulations, Comparison With Experiment , 2001 .

[37]  An Experimental Study of the Rapid Flow of Dry Cohesionless Metal Powders , 1986 .

[38]  Nicolas Fillot,et al.  A Granular Dynamic Model for the Degradation of Material , 2003 .