Harmonic vibrations of high-speed rotors in momentum exchange devices are primary disturbances for attitude control of spacecraft. Active magnetic bearings (AMBs), offering the ability to control the AMB-rotor dynamic behaviors, are preferred in high-precision and micro-vibration applications, such as high-solution Earth observation satellites. However, undesirable harmonic displacements, curre...

The triaxiality of odd-mass nuclei is investigated by coupling a quasiparticle to an even-even core through the core-quasiparticle model. Both soft and rigid triaxial cores are considered. “soft core” described collective model with rotation-vibrational motion, while “rigid rotor model, which limiting case only rotational motion. We show that presence odd modifies quadrupole dynamics appear mor...

The paper deals with the electromagnetic forces in induction machines when the rotor is performing eccentric motion with respect to the stator. The studied eccentric motions of the rigid cage rotor are cylindrical circular whirling motion, symmetric conical whirling motion and the combination of these two basic modes of eccentric motions. The multi-slice, time stepping finite element analysis i...

Zhang, Yongheng M.S.E., Purdue University, August 2009. Modeling and Hover Control of a Double-Rotor Micro Flying Robot via Shape Change. Major Professor: Nasser Houshangi. Research in Micro Aerial Vehicles (MAVs) has been proliferating in both academia and industry during recent years due to their potential applications, e.g. search and rescue in the aftermath of an earthquake. Among others, c...

The two main sources contributing to scroll compressor vibration at running frequency are the residual rotational unbalance in the crank-rotor assembly and the reciprocating force due to the Oldham ring. The intent of this paper is to develop a rigid body model of the compressor vibrating on resilient grommets. This model is a design tool capable of identifying the sensitivity, of the steady-st...

In this work, different modelling aspects of helicopter aerodynamics are discussed. The helicopter model is on Sikorsky configuration, main rotor in perpendicular combination with a tail rotor. The rotors are articulated and their blades are rigid. The main rotor implementation takes into account flap, lag and feather degrees of freedom for each of the equispaced blades as well as their dynamic...

In this paper, the aerodynamic characteristic of a ducted tail rotor in hover has been numerically studied using CFD method. An analytical time domain formulation based on Ffowcs Williams-Hawkings (FW-H) equation is derived for the prediction of the acoustic velocity field and used as Neumann boundary condition on a rigid scattering surface. In order to predict the aerodynamic noise, a hybrid m...

IBM-1 calculations for the fission products 108,110,112Ru have been carried out. The even-even isotopes of Ru can be described as transitional nuclei situated between the U(5) (spherical vibrator) and SO(6) (γ-unstable rotor) symmetries of the Interacting Boson Model. At first, a Hamiltonian with only oneand two-body terms has been used. Excitation energies and B(E2) ratios of gamma transitions...

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