Threshold Performance Optimization of a Rotor-Bearing System Subjected to Leakage Excitation

1990 ◽  
Vol 112 (4) ◽  
pp. 439-444 ◽  
Author(s):  
J. H. Wang ◽  
F. M. Shih
Keyword(s):  
Performance Optimization ◽  
Optimization Technique ◽  
Fluid Leakage ◽  
Rotor Bearing ◽  
Bearing System ◽  
Blade Tips

Fluid leakage in blade tips in turbomachinery may induce instability and limit and output rating. In this work, the optimization technique has been used to find diameters of shaft elements and bearing supports so that the optimized rotor-bearing system can sustain a larger fluid leakage force. The results show that the threshold performance of rotor-bearing systems can be significantly improved by slight modifications of the shaft diameters. The results also indicate that the threshold performance can be improved more significantly by the combination of optimum bearing supports and optimum shaft diameters.

Threshold Performance Optimization of a Rotor-Bearing System Subjected to Leakage Excitation

1989 ◽  
Author(s):  
J. H. Wang ◽  
F. M. Shih
Keyword(s):  
Performance Optimization ◽  
Optimization Technique ◽  
Slight Modification ◽  
Labyrinth Seal ◽  
Fluid Leakage ◽  
Rotor Bearing ◽  
Bearing System

The fluid leakage in shroud of the blades and the labyrinth seal of turbomachinery may induce instability and limit the output rating. In this work, the optimization technique has been used to find the diameters of shaft elements and the bearing supports so that the optimized rotor-bearing system can sustain larger fluid leakage force. The results show that the threshold performance of rotor-bearing systems can be significantly improved by slight modification of the shaft diameters. The results also indicate that, the threshold performance can be improved more significantly by the combination of optimum bearing supports and optimum shaft diameters.

scholarly journals Optimum Weight Design of a Rotor Bearing System With Dynamic Behavior Constraints

1989 ◽  
Author(s):  
Ting Nung Shiau ◽  
Jon Li Hwang
Keyword(s):  
Dynamic Behavior ◽  
Optimization Technique ◽  
Penalty Function Method ◽  
Efficient Design ◽  
Cross Sectional ◽  
Design Algorithm ◽  
Optimum Weight ◽  
Rotor Bearing ◽  
Weight Design ◽  
Bearing System

An efficient design algorithm for optimum weight design of a rotor bearing system with dynamic behavior constraints is investigated. The constraints include the restrictions on stresses, unbalance response, and/or critical speeds. The system dynamic behaviors are analyzed by the finite element method. And the exterior penalty function method is used as the optimization technique to minimize the system weight. The system design variables are the cross-sectional areas of the shaft and the stiffnesses of the bearings. The sensitivity analysis of the system parameters is also investigated. The example of a single spool rotor bearing system is employeed to demonstrate the merits of the design algorithm with different combination of dynamic behavior constraints. At the optimum stage, it is shown that the weight of rotor system can be significantly reduced. Moreover, the optimum design weights are quite difference for various combinations of dynamic behavior constraints.

The Effect of Anisotropic Support on Rotor Instability Due to Fluid Leakage

1988 ◽  
Vol 110 (4) ◽  
pp. 585-591
Author(s):  
Jhy-Horng Wang ◽  
Ming-Te Tsai
Keyword(s):  
Point Of View ◽  
Simplified Model ◽  
Optimum Range ◽  
Energy Point ◽  
Fluid Leakage ◽  
Rotor Bearing ◽  
Anisotropic Stiffness ◽  
Bearing System

The instability caused by fluid leakage leads to limited performance in turbomachines. This instability may be improved by using flexible bearing supports with anisotropic stiffness. With a simplified model this effect is investigated, including the influence of many parameters. The results show that the optimum range of anistropy is strongly dependent on the parameters of the rotor-bearing system. In this paper an explanation from an energy point of view is presented to clarify the different stability behaviors with anisotropic bearing support.

Improve the Stability of Rotor Subjected to Fluid Leakage by Optimum Diameters Design

1990 ◽  
Vol 112 (1) ◽  
pp. 59-64 ◽  
Author(s):  
J. H. Wang ◽  
F. M. Shih
Keyword(s):  
Total Mass ◽  
High Performance ◽  
Optimization Technique ◽  
Slight Modification ◽  
Labyrinth Seal ◽  
Rotor System ◽  
Fluid Leakage ◽  
Rotor Bearing ◽  
The Stability

For high performance turbomachinery, the fluid leakage in the shroud of the blades and the labyrinth seal may cause instability and limit the output rating. In this work, an optimization technique has been used to find the optimum diameters of shaft elements so that the optimized rotor can sustain maximum fluid leakage excitation. The results show that, even without the increase of total mass of the rotor system, the threshold performance of rotor-bearing systems can be significantly improved by slight modification of the shaft diameters.

Instability Due to Fluid Leakage of a Rotor System With Anisotropic Support

1989 ◽  
Vol 111 (1) ◽  
pp. 27-34
Author(s):  
J. H. Wang ◽  
M. T. Tsai
Keyword(s):  
Element Model ◽  
Point Of View ◽  
Simplified Model ◽  
Optimum Range ◽  
Fluid Leakage ◽  
Rotor Bearing ◽  
The Stability ◽  
Anisotropic Stiffness ◽  
The Finite Element Model ◽  
Bearing System

The instability caused by the fluid leakage leads to a limited performance of turbomachines. This instability may be improved by using flexible bearing supports with anisotropic stiffness. With a simplified model this effect is investigated including the influence of many parameters. The results show that the optimum range of anisotropy is strongly dependent on the parameters of rotor-bearing systems. In this paper an explanation from an energy point of view is presented to clarify the different stability behaviors with anisotropic bearing supports. Beside the simplified model, the stability of the complex rotor-bearing system with anisotropic bearing supports is investigated by the finite element model. An example of a typical 900 MW turbogenerator system is presented.

AN ANALYSIS OF THE ELECTRIC SPINDLE'S DYNAMIC CHARACTERISTICS OF HIGH-SPEED GRINDER

2011 ◽  
Vol 10 (01) ◽  
pp. 159-166 ◽  
Author(s):  
C. H. LI ◽  
Y. L. HOU ◽  
C. DU ◽  
Y. C. DING
Keyword(s):  
Dynamic Characteristics ◽  
Performance Optimization ◽  
High Speed ◽  
Critical Speed ◽  
Structural Parameters ◽  
Influential Factors ◽  
Variable Cross ◽  
Tightening Force ◽  
Rotor Bearing ◽  
Bearing System

Structural parameters are important factors that affect the dynamic performance of the electrical spindle of high-speed grinder. In this study, the influences of the electric spindle's major structural parameters on its dynamic characteristics are investigated. Based on the transfer-matrix method and taking into consideration the gyroscopic couple, the shear, the variable cross-section, and other influential factors, a dynamic model is established for the multidisk rotor of the rotor-bearing system of the electric spindle. The critical speeds of first three orders, the modes of variation, and other dynamic characteristic parameters of the electric spindle are programmed and calculated. The influences of the axial pre-tightening force of the bearing, the span of the fulcrum bearing as well as the changes in the front and rear overhangs on the critical speed of the rotor-bearing system on the electric spindle and their pattern of changes are analyzed. The results show that the span of the fulcrum bearing and the overhang have significant influences on the critical speed within a certain range, and the study provide the basis and guidance for the structural design and performance optimization of the electric spindle.

Optimum Weight Design of a Rotor Bearing System With Dynamic Behavior Constraints

1990 ◽  
Vol 112 (4) ◽  
pp. 454-462 ◽  
Author(s):  
Ting Nung Shiau ◽  
Jon Li Hwang
Keyword(s):  
Dynamic Behavior ◽  
Optimization Technique ◽  
Penalty Function Method ◽  
Efficient Design ◽  
Cross Sectional ◽  
Design Algorithm ◽  
Optimum Weight ◽  
Rotor Bearing ◽  
Weight Design ◽  
Bearing System

An efficient design algorithm for optimum weight design of a rotor bearing system with dynamic behavior constraints is investigated. The constraints include restrictions on stresses, unbalance response, and/or critical speeds. The system dynamic behaviors are analyzed by the finite element method. The exterior penalty function method is used as the optimization technique to minimize the system weight. The system design variables are the cross-sectional areas of the shaft and the stiffnesses of the bearings. The sensitivity analysis of the system parameters is also investigated. The example of a single spool rotor bearing system is employed to demonstrate the merits of the design algorithm with different combinations of dynamic behavior constraints. At the optimum stage, it is shown that the weight of the rotor system can be significantly reduced. Moreover, the optimum design weights are quite different for various combinations of dynamic behavior constraints.

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