The effectiveness of surrogate based optimization of helicopter rotor blades for vibration reduction using kriging global approximations is investigated. The search for the optimal design is conducted using two methods: (1) the “one-shot” approach in which the surrogate is optimized directly and (2) a method based on the expected improvement function which seeks to find optimal designs while re...

In this paper, we present a review of the experimental identification of dynamic parameters of bearings in a rotating machine. Major emphasis is given to vibration-based identification methods and the review encompasses descriptions of experimental measurement techniques, mathematical modeling, parameter extraction algorithms and uncertainty in the estimates applied to a variety of bearings. Th...

In order to reduce the unbalance vibration of the rotating machinery automatically during the work process, a new type of liquid-transfer active balancing system was proposed. In the system, a balancing disc divided into four liquid storage chambers was mounted on the rotor. When the unbalance response of the rotating machinery was higher than the limiting value, compressed air was injected to ...

The dynamic behaviour of a high speed balanced rotor supported on deep groove ball bearings (SKF-6205) has been studied by numerically simulated results. Since, internal radial clearance (IRC) is inevitably present in all class and types of bearing, in this paper it (IRC-C3) is considered as main source of nonlinearity with speed as control parameter. The complex mathematical model simulates no...

This paper presents an analytical study of single-plane automatic balancing of statically and dynamically unbalanced rigid rotors, considering also the effect of partial unbalance compensation and vibration reduction. We consider a rotor equipped with a selfbalancing device consisting of a circular track with moving balls to compensate for rotor unbalance. The investigations include an analysis...

This paper investigates the accuracy of rotor-locked transient-response (RLTR)-based vibration model for switched reluctance machines (SRM). RLTR is stator stimulated by abrupt change radial force when turning off one phase SRM with rotor being locked, total can be modelled as linear superposition series. An electromechanical built to clarify generation vibration, it revealed that some velocity...

This paper studies the non-uniform air-gap caused by stator and rotor deformations, together with its effects on the spatial and temporal spectrum of the radial magnetic force density in an interior permanent magnet synchronous motor (IPMSM). According to the mathematical model of the deformed air-gap length, the superposition method is adopted to derive the air-gap permeance. Then, the formula...

Active vibration control methods for rotors were studied in order to develop solutions to enhance machines’ dynamic behaviour, durability, and operating range. The aim of the thesis was to develop identification and control methods for active vibration control of a rotor. The identification method developed in the thesis improved run-time rotor identification by compensating rotation-related di...

Significant structural vibration is an undesirable characteristic in helicopter flight that leads to structural fatigue, poor ride quality for passengers and high acoustic signature for the vehicle. Previous Individual Blade Control (IBC) techniques based on piezoelectric actuator schemes to reduce these effects have been hindered by electromechanical limitations of piezoelectric actuators. The...

Inter-turn short circuit of field windings (ISCFW) may cause the field current of a generator to increase, output reactive power to decrease, and unit vibration to intensify, seriously affecting its safe and stable operation. Full integration of mechanical and electrical characteristics can improve the sensitivity of online monitoring, and detect the early embryonic period fault of small turns....