Turbocharger is a high speed rotor system supported by a pair of floating ring bearings which comprise of double oil films. The stability of its rotor system is governed by not only the structure of the rotor but also by the nonlinear hydrodynamic force of two oil films. In this paper, a lumped dynamics model is developed for a turbocharger rotor system. In order to investigate the nonlinear be...

This paper presents an active vibration control scheme to reduce unbalanceinduced synchronous vibration in rotor-bearing systems supported on two ball bearings, one of which can be automatically moved to control the effective rotor length and, as an immediate consequence, the rotor stiffness. This dynamic stiffness control scheme, based on frequency analysis, speed control and acceleration sche...

The rotor eddy current losses of a high-speed permanent magnet synchronous motor reduce the efficiency of the motor and increase the temperature rise of the rotor. In severe cases, the permanent magnet of the rotor can be demagnetized, affecting the safe operation of the motor. In this paper, an analytical model of rotor eddy current losses calculation based on Maxwell equations is introduced. ...

In rotor walk on a graph, the exits from each vertex follow a prescribed periodic sequence. We show that any rotor walk on the d-dimensional lattice Z visits at least on the order of t distinct sites in t steps. This result extends to Eulerian graphs with a volume growth condition. In a uniform rotor walk the first exit from each vertex is to a neighbor chosen uniformly at random. We prove a sh...

A rotor configuration on a graph contains in every vertex an infinite ordered sequence of rotors, each is pointing to a neighbor of the vertex. After sampling a configuration according to some probability measure, a rotor walk is a deterministic process: at each step it chooses the next unused rotor in its current location, and uses it to jump to the neighboring vertex to which it points. Rotor...

Submitted for the MAR11 Meeting of The American Physical Society Quantum rotor theory of spinor condensates in tight traps RYAN BARNETT, HOI-YIN HUI, CHIEN-HUNG LIN, JAY D. SAU, S. DAS SARMA, Joint Quantum Institute and Condensed Matter Theory Center — In this talk, we theoretically construct exact mappings of many-particle bosonic systems onto quantum rotor models. In particular, we analyze th...

We address the problem of H gain scheduling of a magnetic bearing rotor system with the speed of the rotor being the scheduling parameter The rotor exhibits signi cant gyroscopics As a result the plant dynamics change with the rotor speed Recent results in the theory of LPV systems can be used to design robust gain scheduled controllers for such a system As opposed to traditional gain schedulin...

The results of strength and gas dynamic improvement of turbocharger TK-32 axial turbine are presented. Turbocharger was manufactured by LLC “Penzadieselmash” (Penza, Russian) and is used as unit boost for diesel locomotive. The goal of this work was to ensure turbine work capacity when rotor speed is increased by 10% without efficiency reduction. The strain-stress state analysis indicated the r...

In a previous article the theory of frame transformation relation between Body Oriented Angular (BOA) states and Lab Weakly Coupled states (LWC) was developed to investigate simple rotor-rotor interactions. By analyzing the quantum spectrum for two coupled diatomic molecules and comparing it with spectrum and probability distribution of simple models, evidence was found that, as we move from a ...

Doubly Excited Brushless Reluctance Machine (DEBRM) has gained much attention recently in the area of variable-speed constant-frequency generating systems and adjustable speed drives. Two types of reluctance rotor structure, axially laminated and simple salient rotors, are suggested in the DEBRM development. Due to the unconventional pole number combination of the stator and rotor, performance ...