An investigation is carried out on the systematic analysis of the dynamic behavior of the hybrid squeeze-film damper HSFD mounted a rotor-bearing system with strongly nonlinear oil-film force and nonlinear rub-impact force in the present study. The dynamic orbits of the system are observed using bifurcation diagrams plotted using the dimensionless rotating speed ratio as control parameters. The...

A miniature linear synchronous motor was designed, fabricated and tested. Actuation was achieved through interaction of traveling magnetic wave, generated by linear array of microcoils on the stator, and permanent magnets on the rotor. Two configurations of the motor were investigated. One with a single hand-assembled permanent magnet on rotor and corresponding array of multiturn microcoils; th...

The Reynolds equation is extended to include the effects of radial deflection in a seal with two flexibly mounted rotors. The resulting pressures are used to obtain the forces and moments introduced in the axial and angular modes by the inclusion of eccentricity in the analysis. The rotor dynamic coefficients relating the forces and moments in these modes to the axial and angular deflection are...

Design and development of vertically-suspended water pumps requires good understanding of the rotor system characteristics with water-lubricated rubber bearings (WLRB). This paper presents a newly-built experimental device to simulate rotor systems with WLRBs, and some initial results on experimental identification of dynamic stiffness coefficients of a long WLRB. In experiments, unbalanced mas...

This paper presents a means for reducing the torque variation during the revolution of a vertical-axis water turbine (VAWaterT) by increasing the blade number. For this purpose, twodimensional CFD analyses have been performed on a straight-bladed Darrieus-type rotor. After describing the computational model and the relative validation procedure, a complete campaign of simulations, based on full...

The paper proposes a novel method for improving performance of a Three Phase wound rotor induction motor using an indirect reactive current control scheme in the rotor. A 3 phase VSI with a dynamic capacitor is connected in the rotor circuit for controlling the reactive current in the rotor. The dynamic capacitor is an Hbridge switch with a capacitor in which the duty ratio of the Hbridge circu...

This paper presents an active vibration control scheme to reduce unbalanceinduced synchronous vibration in rotor-bearing systems supported on two ball bearings, one of which can be automatically moved to control the effective rotor length and, as an immediate consequence, the rotor stiffness. This dynamic stiffness control scheme, based on frequency analysis, speed control and acceleration sche...

The main purpose of this paper is concerned with the sensitivity analysis of main rotor dynamic response pertaining to variation of some relevant system parameters effectively supports the preliminary design of both articulated and hingeless helicopter rotor configurations. The methodology is laid out based on Galerkin solution of partial differential equation (PDE) of main rotor with flexible ...

mixing conditions of nbr/pvc nanocomposites such as mixing temperature, rotor speed and mixing time are determining parameters in rheological, mechanical and morphological properties of the compound. three levels were chosen for each parameter using design expert software via box-behnken method. the nanocomposite samples were melt-mixed in brabender internal mixer. the effect of various mixing ...

The vibration and noise of permanent magnet synchronous motors (PMSM) are mainly caused by unbalanced magnetic pull (UMP). This paper aims to investigate nonlinear vibration in PMSMs. Firstly, the analytical model of the air-gap magnetic field with an eccentric rotor in PMSM is studied, and the analytical model is verified by the finite element method. Then the dynamic model of an offset rotor-...