The effectiveness of surrogate modeling of helicopter vibrations, and the use of the surrogates for optimization of helicopter vibration are studied. The accuracies of kriging, radial basis function interpolation, and polynomial regression surrogates are compared. In addition, the surrogates for the vibratory hub shears and moments are used to generate an objective function which is employed in...

There are a variety of abnormal running conditions in rotating machinery which lead to rotor/stator interaction dynamics which, in turn, can cause a rich mixture of effects associated with rub-related phenomena. These effects manifest themselves in the occurrence of multiple solutions for steady-state vibration response scenarios, including amplitude jumps during rotor acceleration, and vibrati...

The problem of failures in induction motors is a large concern due to its significant influence over industrial production. Therefore a large number of detection techniques were presented to avoid this problem. This paper presents the comparison results of induction motor rotor fault detection using three methods: motor current signature analysis (MCSA), surface vibration (SV), and instantaneou...

The benefits of applying multiple alternatives for mock-up and compression of helicopter harmonic motion are analyzed. Multiple mock-up approaches, along with a weighted-average mechanism, are approximated so that quicksand affiliated with only applying alone better alternate for the rotor blade vibration-reduction dilemma are bypassed. A harmonic motion external function matching to a flight c...

Title of Dissertation: CFD Based Unsteady Aerodynamic Modeling for Rotor Aeroelastic Analysis Jayanarayanan Sitaraman, Doctor of Philosophy, 2003 Dissertation directed by: Associate Professor James D. Baeder Department of Aerospace Engineering A Computational Fluid Dynamics (CFD) analysis is developed for 3-D rotor unsteady aerodynamic load prediction. It is then coupled to a rotor structural a...

Title of Dissertation: DEVELOPMENT OF MACH SCALE ROTORS WITH COMPOSITE TAILORED COUPLINGS FOR VIBRATION REDUCTION Jinsong Bao, Doctor of Philosophy, 2004 Dissertation directed by: Professor Inderjit Chopra Department of Aerospace Engineering The use of composite tailored couplings in rotor blades to reduce vibratory hub loads was studied through design, structural and aeroelastic analysis, fabr...

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...

The magnetically suspended Control Moment Gyroscope (CMG) has the advantages of long-life, micro-vibration and being non-lubricating, and is the ideal actuator for agile maneuver satellite attitude control. However, the stability of the rotor in magnetic bearing and the precision of the output torque of a magnetically suspended CMG are affected by the rapid maneuvers of satellites. In this pape...

This paper inspects the misaligned motors by using diagnostic medium such as current, flux and instantaneous power signal. Misalignments in machines can cause decrease in efficiency and in the long-run it may cause disastrous failure because of unnecessary vibration, stress on motor & bearings and short-circuiting in stator and rotor windings. The measurements have been performed at full-load t...

Rotor dynamics plays an important role in many engineering fields such as gas turbine, steam turbine, reciprocating and centrifugal compressors, the spindle of machine tools, and so on. Owing to the growing demands for high power, high speed, and light weight of the rotor-bearing system, computations of critical speeds and steady-state response at synchronous and sub critical resonances become ...