This paper presents the effect of preload on nonlinear dynamic behavior of a rigid rotor supported by two-lobe aerodynamic noncircular journal bearing. A finite element method is employed to solve the Reynolds equation in static and dynamical states and the dynamical equations are solved using Runge-Kutta method. To analyze the behavior of the rotor center in the horizontal and vertical directi...

in this paper, the static characteristics of two-lobe, three-lobe and four-lobe noncircular gas journal bearing systems are studied in detail. the reynold’s equation governing the noncircular gas bearing systems are analyzed by using radial basis functions (rbf). the solutions are obtained numerically by solving systems of algebraic equations. the equilibrium position of the rotor is obtaine...

in this paper, static performance characteristics for a finite lenght two-lobe journal bearing lubricated with micropolar fluid is studied. using finite element method, steady-state film pressure is obtained by solving modified reynolds equation, based on micropolar lubrication theory. with the help of film pressure in bearing, the static performance characteristics in terms of load carrying ca...

A four-lobe pressure dam bearing which is produced by cutting two pressure dams on the upper two lobes and two relief-tracks on the lower two lobes of an ordinary four-lobe bearing is found to be more stable than a conventional four-lobe bearing. In this paper a four-lobe pressure dam bearing supporting rigid and flexible rotors is analytically investigated to determine its performance when L/D...

This work concerns the dynamics of towed array lifting devices (LFDs), which help to maintain the position of a tow line being dragged behind a vessel. The LFD satisfies the non-dimensional quadratically damped Mathieu equation ẍ+ (δ + 2 cos t)x+ ẋ |ẋ| = 0. Numerical study of this equation shows a wide array of dynamical features. The dynamical features of the system are exploited to obtain a c...

This paper analyzes the effect of turbulence on the performance of an inverted threelobe pressure dam bearing which is produced by incorporating a pressure dam in the upper lobe and two relief tracks in the lower two lobes of an ordinary inverted threelobe bearing. For analysis purpose different values (0, 1500, 3000, and 6000) of Reynolds number are considered to study the effect of turbulence...

An investigation into the mechanical response of pneumatically-spliced carbon fibre yarns as a potential reinforcing material for polymer composites is presented. High strength connections between are produced by joining short discontinuous tows longer lengths via entanglement. The effect altering number high-pressure air pulses fired commercially available (Airbond 701H) splicing machine, to f...

In the course of a detailed investigation of the infant mortality statistics of Aberdeen from 1856 to 1926, and of the various factors which might be considered to have a bearing on this mortality, including a comparison of the conditions of life in the four principal Scottish townls, it was discovered that the infant deaths from developmental causes formed the most important group. It is propo...

The purpose of this study was to determine the influence of towing force magnitude on the kinematics of supramaximal sprinting. Ten high school and college-age track and field athletes (6 men, 4 women) ran 60-m maximal sprints under 5 different conditions: Nontowed, Tow A (2.0% body weight [BW]), Tow B (2.8% BW), Tow C (3.8% BW), and Tow D (4.7% BW). Three-dimensional kinematics of a 4-segment ...

Fibrous tows used in continuous fibre-reinforced polymers (CFRPs) deform geometrically during the production of composite products. The cross-sectional geometry of the tow is influenced by the load-induced deformation mechanisms. A study of the effect of two commonly assumed geometrical tow shapes on an equivalent pressure distribution in a tow-on-a-pin spreading arrangement was performed. The ...