Oil-free microturbomachinery (MTM) are inevitably subjected to base or foundation excitations: passenger and commercial transportation vehicles experiencing intermittent excitation from road conditions, and (multiple) periodic load excitations from internal combustion (IC) engines in turbochargers, for example. Too large base excitations can produce severe damage, even failure, due to hard coll...

The latest development in screw compressor (helical lobed compressor) rotor profile design and rotor manufacturing machinery have prioritized basic rotor profile surface, lead and divide. However, one error that at frrst looks very basic but at the same time almost impossible to eliminate, is dealt with in this paper. The error is rotor runout.

An aeroelastic model of a smart rotor system (which incorporates blade-mounted trailing-edge flap actuators and conventional root pitch actuation) is presented in linear time invariant state space form. The servo-flap deflections are modeled as producing incremental lift and moment variations, so that any linear aerodynamic actuator can be evaluated. This smart rotor model is used to conduct pa...

The compatibility between a composite beam cross-sectional analysis based on the variational asymptotic approach, and a helicopter rotor blade model which is part of a comprehensive rotorcraft analysis code is examined. It was found that the finite element cross-sectional analysis code VABS can be combined with a moderate deflection rotor blade model in spite of the differences between the form...

This paper present a new advanced control algorithm based on continuous minimization of predicted tracking errors, to achieve torque, rotor speed and rotor flux amplitude tracking objectives. This algorithm called a new Adaptive Nonlinear Predictive Control to induction motor drive uses a combination of the adaptive observer for rotor flux and Cascaded Nonlinear Predictive Control technique. Th...

This paper proposes an adaptive flux observer for induction motors, where stator and rotor resistances are estimated in online environments. The variation of motor parameters during operation degrades the performance of the controller and the flux observer. Among the parameters of induction motors, rotor resistance is a crucial one for flux estimation, and stator resistance also becomes critica...

This report contains the results of a full-scale experimental feasibility study of rotor isolation employing the Dynamic Antiresonant Vibration Isolator (DAVI) . The full-scale experiments were performed on a UH-2 helicopter fuselage isolated from a simulated rotor and transmission. Tests were conducted for three directions of vibratory input at the hub on the nonisolated vehicle and then compa...

Progressive cavity pumps are used in industry for the circulation of high viscosity fluids, such as crude oil and petroleum products, sewage sludge, oils, salt water, wastewater. Also known single screw pumps, these composed a rotor which has shape rounded screw, moves inside rubber stator. The stator an double helical internal surface which, together with rotor, creates that along rotor. movem...

An automatic rotor trim control system was developed and successfully used during a wind tunnel test of a full-scale UH-60 rotor system with Individual Blade Control (IBC) actuators. The trim control system allowed rotor trim to be set more quickly, precisely and repeatably than in previous wind tunnel tests. This control system also allowed the rotor trim state to be maintained during transien...