We report a novel rotary piezoelectric motor using bending transducers in this work. Three transducers are used to drive a disk-shaped rotor together by the elliptical movements of their driving tips; these motions are produced by the hybrid of two first bending vibration modes. The proposed piezoelectric transducer has a simple structure as it only contains an aluminum alloy beam and four piec...

A procedure that automatically identifies internal rotation modes and rotating groups during the normal mode vibrational analysis is outlined, and an improved approximation to the corrections for the thermodynamic functions is proposed. The identification and the characterization of the internal rotation modes require no user intervention and make extensive use of the information imbedded in th...

Using the ab initio potential of Shin ef al. (to be published), we have calculated the bound states and infrared absorption spectrum of the van der Waals complex Ar.+CO. The results show that Ar.*CO cannot be treated as a quasirigid rotor, nor as a molecule with a free internal rotor. In particular, a transition to the first excited van der Waals bending level is predicted to be present in the ...

This paper studies the load reduction potential of a prototyped “smart” rotor. This is, a rotor where the blades are equipped with a number of control devices that locally change the lift profile on the blade, combined with appropriate sensors and controllers. Experimental models, using dedicated system identification techniques, are developed of a scaled rotating two-bladed “smart” rotor of wh...

Laboratory testing of tidal turbine models is an essential tool to investigate hydrodynamic interactions between turbines and the flow. Such tests can be used to calibrate numerical models and to estimate rotor loading and wake development to inform the design of full scale machines and array layout. The details of the design and manufacturing techniques used to develop a highly instrumented tu...

Bending stiffness variation (BSV) is a common problem causing vibration in large rotating machinery. BSV describes lateral bending and its as function of the rotational angle. It has been observed that causes excitation exactly twice per revolution, which leads to problems, especially at half critical speed. caused by rotor geometry errors if material assumed be homogeneous linearly elastic. Th...

In almost all production of electricity the rotating machines serves as an important part of the energy transformation system. In hydropower units, a hydraulic turbine connected to a generator converts the potential energy stored in the water reservoir into electrical energy in the generator. An essential part of this energy conversion is the rotating system of which the turbine and the generat...

This paper shows the load comparisons between the numerical simulation and the full-scale load measurement data. First part of this paper includes the comparisons of statistic load in terms of maximum, mean, and minimum values for the selected normal operation cases. The blade root bending moments and tower top bending moments are compared. Second part of this paper introduces the dynamic respo...

Active magnetic bearing (AMB) systems support rotating shafts without any physical contact, using electromagnetic forces. Each radial AMB uses two pairs of electromagnets at opposite sides of the rotor. This allows the rotor to float in the air gap, and the machine to operate without frictional losses. In active magnetic suspension, displacement sensors are necessary to detect the radial and ax...

The paper proposes a methodology for reliable design and maintenance of wind turbine rotor blades using a condition monitoring approach and a damage tolerance index coupling the material and structure. By improving the understanding of material properties that control damage propagation it will be possible to combine damage tolerant structural design, monitoring systems, inspection techniques a...