A turbo compressor was investigated to ensure the operational reliability of charging fuel cell systems. This study air-lubricated herringbone bearings support high-speed rotating shaft. For reliable operation rotor bearing system, stable in whole speed range (up 120 krpm), as well low lift-off speed, is an important issue. Some publications containing guidelines for optimized design terms stab...

System of ],. 1. Introduction.-The whirling of shafts carrying rotors is a subject which has attracted the attention of many engineers and mathematicians notably Dunkeffey 4, Chree 1, Stodola 8, Jeffcott 5 and Morris 6,7 during the past fifty years. The last mentioned writer has given some valuable historical surveys and criticisms in addition to his own elucidation of several aspects of the ge...

this work deals with effects of asymmetric stiffness on the dynamic behaviour of the rotor system. the analysis is presented through an extended lagrangian hamiltonian mechanics on the asymmetric rotor system, where symmetries are broken in terms of the rotor stiffness. the complete dynamics of asymmetries of rotor system is investigated with a case study. in this work, a mathematical model is ...

Purpose The supercritical design of tail rotor drive shaft has attracted more attention in helicopter due to its high power–weight ratio and low maintenance cost. However, there exists excessive vibration when the passes through critical frequency. Dry friction damper is equipment applied suppress vibration. In order figure out damping mechanism dry improve efficiency, dynamic model shaft/dampe...

most of the methods that have been proposed for speed estimation of induction machines require the rotor and the stator resistance to change in the normal operating range. on the other hand, estimation of the rotor resistance requires rotor speed. in this paper, after studying conditions for simultaneous estimation of rotor speed and rotor resistance, a method for simultaneous estimation of rot...

the rotor of enegelberg whitener was equipped with a screw conveyor to reduce broken rice percentage. according to preliminary experiments this modification could reduce broken rice percentage about 2.5%. further experiment was performed to determine the effect of rotor speeds and blade positions on white rice quality. to do this, five rotor speeds, consisting 500, 600, 700, 800 and 900 r.p.m a...

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 such ...

in this research, the steady-state flow filed around a 3d body and rotor configuration of the robin helicopter is simulated. the rotor is modeled by an actuator disk. for this purpose, an annular computational domain replaces the rotor and some modeled source terms are added to the momentum equations. this modeling of rotor considerably speed up computational time. the flow field over this heli...