In this paper, we characterize the rotational dynamics and observe rotor-rotor interactions within a crystalline, three-dimensional array of dipolar molecular rotors. The rotating portion of each rotor molecule consists of a dipolar fluorine-substituted phenyl group. The phenyl rotors are connected by acetylene linkages to bulky triphenyl methyl groups which are held rigid in the crystal lattic...

Rolling bearings are one of the most important uproar and vibration generator into mechanical constructions. According to that, it is very important to know ascendancy of rolling bearing construction to main parameters which determine level of uproar and vibrations produced inside machines. This paper present new mathematical model of dynamic behavior of rigid rotor inside the rolling bearing. ...

This paper describes the development of H∞ controllers for two helicopter models. The study was first carried out using rigid body state feedback only and was then extended to include the rotor flap and lag states. It was observed that the H∞ controllers gave better robustness and performance than the baseline controllers. Moreover, using rotor state feedback, it was possible to design high ban...

Robust attitude tracking control of a small-scale aerobatic helicopter using geometric and backstepping techniques is presented in this article. A nonlinear coupled rotor-fuselage dynamics model of the helicopter is considered, wherein the rotor flap dynamics is modeled as a first order system, while the fuselage is as a rigid body dynamically coupled to the rotor system. The robustness of the ...

This paper describes the development of H∞ controllers for two helicopter models. The study was first carried out using rigid body state feedback only and was then extended to include the rotor flap and lag states. It was observed that the H∞ controllers gave better robustness and performance than the baseline controllers. Moreover, using rotor state feedback, it was possible to design high ban...

Efficient, small-scale fixed-pitch rotor blades are essential for miniature rotorcraft. Extremely thin blade sections are required for highly efficient rotor performance that leads to acceptable mission endurance. Such rotor blades are difficult to manufacture from sufficiently rigid material to avoid significant torsional deformation in operating conditions. In practice, it is necessary to tra...

The exchange and inelastic state-to-state cross sections for the OH(+) + H collisions are computed from wave packet calculations using the doublet and quartet ground electronic potential energy surface (PES) correlating to the open shell reactants, for collision energies in the range of 1 meV to 0.7 eV. The doublet PES presents a deep insertion well, of ≈6 eV, but the exchange reaction has a ra...