A nano coaxial rotor was designed, fabricated and studied experimentally at an ultralow Reynolds number ranging from 5000 to 20,000. The Minimum Induced Loss theory was employed to optimize the geometry of nano coaxial rotor with the introduction of weights to take into account the interference of upper rotor and lower rotor. The chord and twist distributions of both rotors were achieved as a r...

This work deals with effects of asymmetric stiffness on the dynamic behaviour of the rotor system. The analysis is presented through an extended Lagrangian Hamiltonian mechanics on the asymmetric rotor system, where symmetries are broken in terms of the rotor stiffness. The complete dynamics of asymmetries of rotor system is investigated with a case study. In this work, a mathematical model is ...

In this article, turbulent flow heat transfer in the air gap between rotor and stator of a generator under nonhomogeneous heat flux is studied experimentally. The rotor consists of four symmetrical triangular grooves. The stator surface is smooth and does not include any grooves. The relative heat flux between the rotor and the stator is 1 to 3. Temperature and heat flux are measured locally at...

Crack fault of rotor is one of the most prominent problems faced by magnetic bearing rotor system. In order to improve the safety performance of this kind of machinery, it is necessary to research the vibration characteristics of magnetic bearing cracked rotor system. In this paper, the stiffness model of the crack shaft element was established by the strain energy release rate (SERR) theory. T...

The effects of lobe tip design parameters on compressor performance were evaluated by utilizing a computer simulation package and taking SRM-D asymmetric type rotor profile as an example. The result suggests that the requirements for high efficiency, large capacity, low inter-rotor contact force and low viscous friction loss do not always lead to the use of the same lobe tip designs. Of all the...

In the rotor reference frame, the input-output linearization theory was adopted to decouple the rotor position and rotor flux. We then designed two adaptation laws to estimate the rotor resistance and mechanical parameters of the motor. The passive properties of the negative feedback connection from the rotor flux observer to the rotor resistance estimator, and the position controller were anal...

This study presents a designing process for refurbishing of a 32 MW rotor-generator damaged coupling. The reason of rotor damage was being hit by the quivers of an explosion. The original coupling was union with the rotor formed after a machining process on a mono block forged rotor. In some areas imposed damages caused the breaking off and detachment of some parts in the coupling flange. Becau...

In this description of the Enigma rotor movement sequence the following conventions have been adopted. The three rotors are numbered from right to left as seen from the machine operator’s viewpoint thus, the ‘fast’ or right hand rotor is Rotor 1, Rotor 2 is in the middle position and the ‘slow’ or left hand rotor is Rotor 3. The associated ratchets, stepping levers and notches are similarly des...

Effects of magnetic saturation on various equivalent circuit models of an induction motor are studied. The parameters of 2.2-kW and 37-kW motors with closed rotor slots are analyzed using finite element computations. Both skewed and unskewed rotor slots are studied. The magnetizing inductance not only depends on the main flux, but is also dependent on the rotor current, especially if the rotor ...

A new online identification methodology for estimation of the rotor flux components and the main electrical parameters of vector controlled induction motors is presented in this paper. The induction motor model is referred to the rotor reference frame for estimation of rotor flux and rotor parameters, and referred to the stator reference frame to estimate stator parameters. The stator parameter...