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2 edition of Effect of rotor wedges on the stiffness, damping and parameters of turbine generators found in the catalog.

Effect of rotor wedges on the stiffness, damping and parameters of turbine generators

A.M Mohamed Ebrahim

Effect of rotor wedges on the stiffness, damping and parameters of turbine generators

by A.M Mohamed Ebrahim

  • 292 Want to read
  • 23 Currently reading

Published by UMIST in Manchester .
Written in English


Edition Notes

StatementA.M. Mohamed Ebrahim ; supervised by A.B.J. Reece.
ContributionsReece, A.B.J., Electrical Engineering and Electronics.
ID Numbers
Open LibraryOL20159955M

1 AERODYNAMIC DAMPING AND THE SEISMIC RESPONSE 2 OF HORIZONTAL AXIS WIND TURBINE TOWERS 3 V. Valamanesha, S.M. ASCE and A.T. Myersb M. ASCE 4 a Graduate Research Assistant, Department of Civil and Environmental Engineering, Huntington 5 Ave, Snell Engineering Center, Northeastern University, Boston, MA , USA, 6 [email protected] Size: 2MB. The stiffness of the control system has a strong effect on aeroelastic stability. Previous research (Ref. 6) showed that a large increase in stability was obtained with double the baseline pitch stiffness, but further increases in stiffness yielded progressively diminishing increases in damping. A stiffness factor of two was used for the File Size: KB.

Rotor blade structural damping was determined from amplitude reduction of free vibration. The blades were excited to vibrate with the first (resonant) oscillation mode with continuously decreasing amplitude due to damping effects. The original records obtained from these tests. Emphasis is placed to the inclusion of composite material coupling effects, first in the blade section stiffness and damping matrices and finally into the stiffness and damping matrices of the finite element. Evaluations of the beam element are presented, to quantify the material coupling effect on composite beams of simple box by:

The turbine wheel is connected to the shaft by a weld Calculation of the bearing stiffness and damping coefficients 5. Stability analysis and run-up simulation of the coupled system between the individual rotor elements and determining the effect of local pre-stress due to the nut fastener assembly. In the case of our.   Effects of Contact Interface Parameters on Vibration of Turbine Bladed Disks With Underplatform Dampers J. Eng. Gas Turbines Power (March, ) Numerical and Experimental Damping Assessment of a Thin-Walled Friction Damper in the Rotating Setup With High Pressure Turbine Cited by:


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Effect of rotor wedges on the stiffness, damping and parameters of turbine generators by A.M Mohamed Ebrahim Download PDF EPUB FB2

A typical turbine generator rotor damping structure consists of damping bars which are made from copper and distributed on both sides of pole face, rotor iron core made from magnetic alloy steel, slot wedge made from aluminum or stainless steel.The three components are represented by (1), (2) and (3) in Fig.

eddy current induced in three components of rotor damping structure is Cited by: 8. Parametrically Induced Damping in a Cracked Rotor The rotor with a periodically varied stiffness can be modeled as a parametrically excited linear system.

This paper presents the results of a numerical analysis of the influence of Rayleigh’s damping and gyroscopic effects on the increase in damping in a parametrically excited rotor Cited by: 1. Rotor dynamics analysis is an important calculation step to design efficient and reliable rotating equipment.

When calculating the rotor dynamics of systems with hydrodynamic bearings, the non-linear fluid film forces are reduced to linearize stiffness and damping coefficients. D damping matrix; K stiffness matrix; B input matrix for external torques. Since the damping matrix of a steel shaft system is more or less a fixed parameter, the method is based on applying an additional electrical torque through the stator winding, thus causing the same effect as one (or more) increased damping coefficient(s).

In order toFile Size: 1MB. horizontal rotor on a flexible isotropic shaft with asymmetric end bearings providing distinctly different elastic and damping characteristics in two fixed reference directions. The analysis includes the effects of rotatory inertia, gyroscopic couple, coriolis force and internal and external damping giving rise to a set of differentialFile Size: KB.

Two aerodynamic damping models are proposed: (1) a model based on the analysis of the rotor aerodynamics incorporating the tower-top motion of a constant-speed wind turbine, which is. element modelling and dynamic analysis of Turbo generator foundation are considered. The frequency dependent soil impedance (stiffness & damping) for various mode shapes are addressed in this study.

The soil-foundation system was simulated in SAP: software and dynamic response of foundation was Size: KB. 10th International Conference on Vibrations in Rotating Machinery 11–13 SeptemberIMechE London, UK material tests have to be performed which results in material master curves that can be transformed into classical stiffness and damping parameters generally used in rotordynamic numerical simulation and analyses.

The effect of. The use of mass- and stiffness-proportional terms in Rayleigh damping is important in finite-element analysis because the mass-proportional term will have a damping effect that decreases with frequency and the stiffness proportional term will have a damping effect.

This has the effect, however, of reducing the inherent generator damping torque; consequently, under certain load conditions, generator rotor swings following system changes will have little damping.

As the component of torque in question is strongly associated with rotor speed, a logical starting point for investigation is the generator torque.

motion is executed and a damping model is derived from the data. The aerodynamic damping forces acting on the turbine blades can have a significant effect on the models response when the rotor shaft is excited by line-to-line shorts in the turbine gen-erator.

NOMENCLATURE C Damping matrix E modal Modal energy of blade vibration J Inertia matrix. The Effect of Rotor Blade Thickness and Surface Finish on the erformance of a Small Axial Flow Turbine Richard J.

Roelke National Aeronautics and Space Administration Lewis Research Center and Jeffrey E. Haas Propulsion Laboratory AVRADCOM Research and Technology Laboratories Lewis Research Center Work performed for U.S.

DEPARTMENT OF ENERGY. Balancing of rotors, hard or soft • The combination of the rotor length and the rotor weight gives in our cases a “stiff” rotor with only the first critical speed visible on site during the start up and shutdownthe start up and shutdown. • The second critical speed can sometimes be seen in the balancing pit between and rpm.

used to identify beari ng stiffness, damping and shaft. three-trial weight to balance turbine generators. Many parameters where tested here such as rotor width, unbalance mass magnitude.

Effect of the shaft stiffness on the inertial response of the fixed speed wind turbines and its contribution to the system inertia this inherent link is not present in wind turbine generators.

In addition, the impact of the foundation stiffness, damping and the effects of long term cyclic loading on the dynamic structural response has been investigated and quantified. Influence of damping winding, controller settings and exciter on the damping of rotor angle oscillations in a hydroelectric generator 4 1 Introduction A different model, [1] compared with the accepted model, has been expanded and tested to calculate the synchronizing and damping components of.

A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. A parametric analysis is carried out on the friction contact parameters and the correct setup of the nonlinear contact model to determine their influence on the dynamic response and to define the required accuracy of the input by:   Damping and stiffness, a primer The stiffness of the rotor supports is very important, as is the stiffness of the rotor itself.

Again we see the same effect where damping increases exponentially at the smaller film thicknesses. Using the same equation, changing only the oil viscosity for that of air, and calculating the damping at 5. The effect of bearings is expressed in form of stiffness and damping coefficients which are varying with rotating speed.

Attention is paid to the influence of rotational speed, eccentric condition, and the stiffness of coupling on the dynamic behavior of two-rotor three-bearing system and Author: Jianfei Yao, Jinji Gao, Ya Zhang, Weimin Wang.E ects of Increasing Tip Speed on Wind Turbine Rotor Design Brian Resor Sandia National Laboratories 1 Wind Energy Technologies Department Janu NREL Systems Engineering Workshop 1 Sandia National Laboratories is a multi-program laboratory managed and .A general vibration model of a flexible rotor system is established to investigate the influences of the damping characteristics on vibration behaviors.

Based on the multi-scale method, the analytical solutions of steady-state and transient-state are derived under the positive and negative conditions of nonlinear damping. The physical significance of the coefficients and their influences on Author: Min Wu, Shengbo Yang, Wen Bao, Jinfu Yang.