Modally Tuned Influence Coefficients for Low-Speed Balancing of Flexible Rotors

2013 ◽  
Vol 136 (2) ◽  
Author(s):  
Y. A. Khulief ◽  
Wasiu Oke ◽  
M. A. Mohiuddin
Keyword(s):  
Experimental Test ◽  
High Speed ◽  
Mode Shapes ◽  
Flexible Rotor ◽  
Test Rig ◽  
Low Speed ◽  
Modal Characteristics ◽  
Flexible Rotors ◽  
Influence Coefficients ◽  
Experimental Test Rig

The need to devise a low-speed balancing method for balancing high-speed rotors was recognized and addressed. In this paper, a scheme that combines both the influence coefficients and modal balancing techniques is presented. The scheme is developed for low-speed balancing of high-speed rotors, and relies on knowledge of the modal characteristics of the rotor. The conditions for applicability of the method were stated in the light of the experientially estimated rotor deflection mode shapes. An experimental test rig of a flexible rotor was constructed to verify the applicability and reliability of the low-speed balancing scheme.

Modally-Tuned Influence Coefficients for Low-Speed Balancing of Flexible Rotors

2011 ◽  
Author(s):  
Y. A. Khulief ◽  
M. A. Mohiuddin
Keyword(s):  
Experimental Test ◽  
High Speed ◽  
Mode Shapes ◽  
Flexible Rotor ◽  
Test Rig ◽  
Low Speed ◽  
Modal Characteristics ◽  
Flexible Rotors ◽  
Influence Coefficients ◽  
Experimental Test Rig

The need to devise a low-speed balancing method for balancing high-speed rotors was recognized and addressed. In this paper, a scheme that combines both the influence coefficients and modal balancing techniques is presented. The scheme is developed for low-speed balancing of high-speed rotors, and relies on knowledge of modal characteristics of the rotor. The conditions for applicability of the method were stated in the light of the experientially estimated rotor deflection mode shapes. An experimental test rig of a flexible rotor was constructed to verify the applicability and reliability of the low-speed balancing scheme.

NUMERICAL STUDY AND DEVELOPMENT OF AN EXPERIMENTAL TEST-RIG CONFIGURATION OF A SUPERSONIC NOZZLE FOR GAS SEPARATION

2021 ◽  
Author(s):  
Rodrigo Fazioli Gastaldo ◽  
Julian Camilo Restrepo Lozano ◽  
Ricardo Galdino da SIlva ◽  
Reinaldo Marcondes Orselli ◽  
José Roberto Simões Moreira ◽  
...  
Keyword(s):  
Gas Separation ◽  
Experimental Test ◽  
Numerical Study ◽  
Supersonic Nozzle ◽  
Test Rig ◽  
Experimental Test Rig

Demonstration of a Unified Approach to the Balancing of Flexible Rotors

1981 ◽  
Vol 103 (1) ◽  
pp. 101-107 ◽  
Author(s):  
M. S. Darlow ◽  
A. J. Smalley ◽  
A. G. Parkinson
Keyword(s):  
Power Transmission ◽  
Substantial Reduction ◽  
Influence Coefficient ◽  
Flexible Rotor ◽  
Unified Approach ◽  
Test Rig ◽  
Multiple Mode ◽  
Flexible Rotors ◽  
Transmission Shaft ◽  
Rotor Balancing

A flexible rotor balancing procedure, which incorporates the advantages and eliminates the disadvantages of the modal and influence coefficient procedures, has been developed and implemented. This new procedure, referred to as the Unified Balancing Approach, has been demonstrated on a supercritical power transmission shaft test rig. The test rig was successfully balanced through four flexural critical speeds with a substantial reduction in effort as compared with the effort required in modal and influence coefficient balancing procedures. A brief discussion of the Unified Balancing Approach and its relationship to the modal and influence coefficient methods is presented. A series of tests which were performed to evaluate the effectiveness of various balancing techniques are described. The results of the Unified Balancing Approach tests are presented and discussed. These results confirm the superiority of this balancing procedure for the supercritical shaft test rig in particular and for multiple-mode balancing in general.

Laser Balancing Demonstration on a High-Speed Flexible Rotor

1979 ◽  
Author(s):  
R. S. DeMuth ◽  
D. P. Fleming ◽  
R. A. Rio
Keyword(s):  
Material Removal ◽  
High Speed ◽  
Metal Removal ◽  
Flexible Rotor ◽  
Test Rig ◽  
Laser Material ◽  
Removal Method ◽  
Before And After ◽  
Optical Configuration ◽  
Neodymium Glass

This paper describes a flexible rotor system used for two-plane laser balancing and an experimental demonstration of the laser material removal method for balancing. A laboratory test rotor was modified to accept balancing corrections using a laser metal removal method while the rotor is at operating speed. The laser setup hardware required to balance the rotor using two correction planes is described. The test rig optical configuration and a neodymium glass laser were assembled and calibrated for material removal rates. Rotor amplitudes before and after balancing, trial and correction weights, rotor speed during operation of laser, and balancing time were documented. The rotor was balanced through the first bending critical speed using the laser material removal procedure to apply trial weights and correction weights without stopping the rotor.

Recovery Control for Rotors Established in Stable Periodic Contact Modes

2007 ◽  
Author(s):  
Michael Schlotter ◽  
Patrick Keogh
Keyword(s):  
Contact Point ◽  
Contact Dynamics ◽  
Test Facility ◽  
Flexible Rotor ◽  
Disk System ◽  
Flexible Rotors ◽  
Influence Coefficients ◽  
Highly Nonlinear ◽  
Periodic Contact ◽  
Stable Periodic

Previous research has shown that flexible rotors can become established in potentially damaging stable periodic contact modes after initial impact with housings, seals, or auxiliary bearings. These modes are characterized by periodic motion and a fixed contact point in a rotating frame. A contact recovery strategy is developed, with the aim to destabilize the modes and return the rotor to a contact-free orbit. This is achieved by applying compensation forces through magnetic bearings, which reduces the effective synchronous forcing that is causing the contact to a low level. It is shown that even in presence of highly nonlinear contact dynamics, a linear FEM rotor model can be used to calculate appropriate influence coefficients. The contact recovery principle is demonstrated by simulations of a simple disk system and a simple flexible rotor. It is then applied to an experimental flexible rotor test facility. Error margins are investigated, and possible limitations of the method are discussed.

Analysis of Failure Modes of a Thermoplastic One-Way Clutch

1991 ◽  
Vol 205 (3) ◽  
pp. 209-215 ◽  
Author(s):  
S C Burgess ◽  
T A Stolarski ◽  
S Karp
Keyword(s):  
Experimental Test ◽  
Failure Modes ◽  
Power Transmission ◽  
Experimental Results ◽  
Test Rig ◽  
New Type ◽  
Experimental Test Rig

This paper presents an analysis of the failure modes during power transmission of a new type of one-way clutch called an expansible-band clutch. The new clutch is made from thermoplastic materials and an experimental test rig has been used to test two material combinations to failure. The experimental results are compared with predictions obtained from empirical formulae. The differences in the two sets of results are used to make conclusions about the failure processes.

Theoretical and Experimental Studies on Squeeze Film Stabilizers for Flexible Rotor-Bearing Systems Using Newtonian and Viscoelastic Lubricants

1990 ◽  
Vol 112 (4) ◽  
pp. 473-482 ◽  
Author(s):  
B. Halder ◽  
A. Mukherjee ◽  
R. Karmakar
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Squeeze Film ◽  
Experimental Investigations ◽  
Flexible Rotor ◽  
Stability Range ◽  
High Speeds ◽  
Flexible Rotors ◽  
Rotor Bearing

A combination of a squeeze film damper and a plane journal bearing is studied as a stabilizing scheme. The damper is made to play the role of a stabilizer to postpone the instability threshold speeds of flexible rotors. Both Newtonian and viscoelastic fluids are used in the rotor-bearing system. Dynamics of the system is theoretically analyzed using bond graphs. Analysis reveals that the use of a Newtonian fluid in the stabilizer largely improves the high speed stability range. However, viscoelastic stabilizing fluid has a detrimental effect on highly flexible rotors. Experimental investigations, conducted on a flexible rotor (natural frequency, 30 Hz), confirm the theoretical findings. In addition, experiments indicate that though the use of viscoelastic stabilizing fluids leads to instability in flexible rotors, the growth of large amplitude whirl is postponed to very high speeds.

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