Hover performance of a twin-rotor test model in terms of rotor overlap sweep, blade collective pitch, and blade tip speedwasexaminedexperimentally.The experimental setup consisted of two three-bladed rotors (tandem rotor configuration) with a diameter of1,220 mm and constant chord of 38 mm, giving a blade aspect ratio of 16.05. The blades were of a rectangular planform with NACA 0012 cross-sect...

This paper presents a comparative study of two types of wound field three-phase switched-flux machine (SFM) with non-overlap winding and salient rotor. Both armature and field winding are located on the stator and rotor is composed of only stack of iron. Non-overlap armature and field windings and toothed-rotor are the clear advantages of these machines as the copper losses gets reduce and roto...

We propose an atom optics experiment to measure the stability of the quantum kicked rotor under perturbations of the Hamiltonian. We avail ourselves of the theory of Loschmidt echoes, i.e., we consider the overlap of a quantum state evolved in a perturbed and an unperturbed potential. Atom interferometry allows us to determine the overlap integral in amplitude and phase. A numerical analysis of...

Direct drive wind turbine generators are gaining importance for light weight, compact design in wind power generation. A new design approach of superconducting wind generator having both axial and radial air gaps between stator and superconducting rotor winding is selected for this simulation work. This paper deals with the simulation of magnetic flux distribution in stator and rotor coil of th...

In this study we investigated the possibility of increasing the visibility of helicopter rotor tips when viewed from the underside. In an experimental study we used a model of a rotor blade spinning at a fast enough rate that it appeared as a transparent disk. The tips of the blades were painted fluorescent red-orange, and were observed under three different lighting conditions. In one conditio...

The use of a shroud around the rotor of a wind turbine has been known to augment the airflow through the rotor plane and hence result in improved performance. This work uses Computational Fluid Dynamics (CFD) to assess the validity of several simple theories which attempt to extend Betz theory to shrouded turbines. Two CFD models are employed and compared to predictions of previously published ...

A rotor dynamic analysis method for the complex three-dimensional design blade was developed and applied to analyzing its aeroelastic stability. Based on medium-size deformation beam theory Hamilton principle, joint transfer matrix used in kinematic compatibility principle assembled finite element develop structural dynamics model. The BO105 validate this characteristic of analyzed detail. resu...