As small rotorcraft grow in capability, the possibilities for their application increase dramatically. Many of these new applications require stable outdoor flight, necessitating a closer look at the aerodynamic response of the aircraft in windy environments. This paper develops the equations of motion for a single-propeller test stand by analyzing the blade-flapping response of a small-stiff p...

We investigate theoretically the dynamics and the charge transport properties of a rod-shaped nanoscale rotor, which is driven by a similar mechanism as the nanomechanical single-electron transistor (NEMSET). We show that a static electric potential gradient can lead to self-excitation of oscillatory or continuous rotational motion. We identify the relevant parameters of the device and study th...

Tip leakage loss introduces major part of losses of the rotor in axial gas turbines. Therefore, the rotor blade tip has a considerable effect on rotor efficiency. To understand the flow physics of the rotor tip leakage, we solve the flow field for different tip platforms (passive flow control) and by considering coolant tip injection (active flow control). Various blade tip configurations s...

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...

A morphing segmented concept is proposed herein for future extreme-scale wind turbine systems. The morphing may be accomplished by using segmented blades connected by screw sockets and a tension cable system. At low wind and rotor speeds, the segmented blades are fully tensioned and set at high pitch to ensure start-up and maximum power at low speeds. At high rotor rpm, the cable tension can be...

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 ...

The electrical characteristics of an isolated induction-generator-based system are improved through the association with a voltage-source pulsewidth modulation (PWM) inverter. The electronic converter allows the achievement of a better system behavior in many aspects: voltage regulation, frequency stabilization, and reactive power compensation. The system operation strategy consists of maintain...