Recently developed techniques in the measurement of fluid film bearing dynamic behaviour, including stiffness and damping, have highlighted some interesting observations on the performance of a range of bearings. These are outlined together with suggested strands of further research aimed at improving the efficiency, reliability and cost of operating plant and equipment.

A model of squeeze-film behavior is developed based on Stokes' equations for viscous, compressible isothermal flows. The flow domain is an axisymmetrical, unit cell approximation of a planar, periodic, perforated microstructure. The model is developed for cases when the lubrication approximation cannot be applied. The complex force generated by vibrations of the diaphragm driving the flow has t...

Recently developed techniques in the measurement of fluid film bearing dynamic behaviour, including stiffness and damping, have highlighted some interesting observations on the performance of a range of bearings. These are outlined together with suggested strands of further research aimed at improving the efficiency, reliability and cost of operating plant and equipment.

We consider the modes of the electric field of a cavity where there is an embedded polarized dielectric film. The model consists in the Maxwell equations coupled to a Duffing oscillator for the film which we assume infinitely thin. We derive the normal modes of the system and show that they are orthogonal with a special scalar product which we introduce. These modes are well suited to describe ...

Using both a recent calculation by Bruch of the damping of the motion of a monolayer nitrogen film oscillating harmonically on a metallic surface due to Ohm's law heating and a Thomas-Fermi approximation treatment of the Ohm's law heating mechanism, which accounts for the nonzero thickness of the surface region of a metal, it is argued that this mechanism for friction is able to account for rec...

We have studied the dynamic structure of thin (approximately a few nanometers) liquid films of a nearly spherical, nonpolar molecule tetrakis(2-ethylhexoxy)silane (TEHOS) by using a combination of atomic force microscopy (AFM) and fluorescence correlation spectroscopy (FCS). Ultra-sensitive interferometer-based AFM was used to determine the stiffness (force gradient) and the damping coefficient...

Original scientific paper This paper presents the electromagnetic analysis of a novel fluid damping based hybrid drive multi-degrees-of-freedom permanent magnet motor based on analytical and 3D finite element methods. The spatial magnetic field calculation model, torque analysis model, oil film model and electromagnetic-thermal coupling are presented and developed. Based on the simulation calcu...

Figure 1: Schematic experimental set up. Squeezed film damping (SFD) is a common phenomenon that occurs in many microdevices when a surface moves normally to another solid surface in close proximity. In microelectromechanical systems (MEMS), SFD is often one of the largest sources of parasitic losses. Therefore, an accurate evaluation of hydrodynamic forces due to the SFD effect is critical in ...

We report on the enhancement of spin Hall angle from CoFeB/Pt interface by introducing nitrogen into Pt thin film. Spin-torque ferromagnetic resonance measurements effective (?SH) reveal a non-monotonic variation as function amount gas introduced, Q in film deposition, which peaks at ?SH = 0.16 when is 8%. Our analysis shows that mainly attributed to increase spin-dependent scattering interface...