Optimal Design of Rotor-Bearing Systems Using Immune-Genetic Algorithm

2001 ◽  
Vol 123 (3) ◽  
pp. 398-401 ◽  
Author(s):  
Byeong-Keun Choi ◽  
Bo-Suk Yang
Keyword(s):  
Genetic Algorithm ◽  
Critical Speed ◽  
Q Factor ◽  
Immune Genetic Algorithm ◽  
Dynamic Constraints ◽  
Design Variables ◽  
Resonance Response ◽  
Rotor Bearing ◽  
Combined Algorithm ◽  
Bearing System

In this paper, the new combined algorithm (Immune-Genetic Algorithm, IGA) is applied to minimize the total weight of the shaft and the resonance response (Q factor), and to yield the critical speeds as far from the operating speed as possible. These factors play very important roles in designing a rotor-bearing system under the dynamic behavior constraints. The shaft diameter, the bearing length and clearance are chosen as the design variables. The results show that the IGA can reduce the weight of the shaft and improve the critical speed and Q factor with dynamic constraints.

Multi-Objective Optimum Design of Rotor-Bearing Systems With Dynamic Constraints Using Immune-Genetic Algorithm

1999 ◽  
Author(s):  
Byung-Gun Choi ◽  
Bo-Suk Yang
Keyword(s):  
Genetic Algorithm ◽  
Immune System ◽  
Optimization Problems ◽  
Q Factor ◽  
Immune Genetic Algorithm ◽  
Dynamic Constraints ◽  
Design Variables ◽  
Resonance Response ◽  
Rotor Bearing ◽  
Combined Algorithm

Abstract An immune system has powerful abilities such as memory, recognition and learning how to respond to invading antigens, and is applying to many engineering algorithms in recent year. In this paper, the combined optimization algorithm (Immune-Genetic Algorithm: IGA) is proposed for multi-optimization problems by introducing the capability of the immune system that controls the proliferation of clones to the genetic algorithm. The new combined algorithm is applied to minimize the total weight of the shaft and the resonance response (Q factor), and to yield the critical speeds as far from the operating speed as possible. These factors play very important roles in designing a rotor-bearing system under the dynamic behavior constraints. The shaft diameter, the bearing length and clearance are chosen as the design variables. The dynamic characteristics are determined by applying the generalized FEM. The results show that the combined algorithm can reduce the weight of the shaft and improve the critical speed and Q factor with dynamic constraints.

Multiobjective Optimum Design of Rotor-Bearing Systems With Dynamic Constraints Using Immune-Genetic Algorithm

1999 ◽  
Vol 123 (1) ◽  
pp. 78-81 ◽  
Author(s):  
B.-K. Choi ◽  
B.-S. Yang
Keyword(s):  
Genetic Algorithm ◽  
Immune System ◽  
Optimum Design ◽  
Optimization Algorithm ◽  
Total Weight ◽  
Two Dimensional ◽  
Immune Genetic Algorithm ◽  
Dynamic Constraints ◽  
Rotor Bearing ◽  
Combined Algorithm

In this paper, the combined optimization algorithm (immune-genetic algorithm) is proposed for multioptimization problems by introducing the capability of the immune system to the genetic algorithm. The optimizing ability of the proposed combined algorithm is identified by comparing the result of optimization with sharing genetic algorithm for the two-dimensional multipeak function. Also the combined algorithm is applied to minimize the total weight of the shaft and the transmitted forces at the bearings. The results show that the combined algorithm can reduce both the weights of the shaft and the transmitted forces at the bearing with dynamic constraints.

Multi-objective Optimization of Rotor-Bearing System With Critical Speed Constraints

1993 ◽  
Vol 115 (2) ◽  
pp. 246-255 ◽  
Author(s):  
T. N. Shiau ◽  
J. R. Chang
Keyword(s):  
Critical Speed ◽  
Expansion Method ◽  
Multi Objective Optimization ◽  
Weighting Method ◽  
Cross Sectional ◽  
Design Algorithm ◽  
Multi Objective ◽  
Design Variables ◽  
Rotor Bearing ◽  
Bearing System

An efficient optimal design algorithm is developed to minimize, individually or simultaneously, the total weight of the shaft and the transmitted forces at the bearings. These factors play very important roles in designing a rotor-bearing system under the constraints of critical speeds. The cross-sectional area of the shaft, the bearing stiffness, and the positions of bearings and disks are chosen as the design variables. The dynamic characteristics are determined by applying the generalized polynomial expansion method and the sensitivity analysis is also investigated. For multi-objective optimization, the weighting method (WM), the goal programming method (GPM), and the fuzzy method (FM) are applied. The results show that the present multi-objective optimization algorithm can greatly reduce both the weight of the shaft and the forces at the bearings with critical speed constraints.

scholarly journals Dynamic Characteristics and Experimental Research of a Two-Span Rotor-Bearing System with Rub-Impact Fault

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Rui Zhu ◽  
Guang-chao Wang ◽  
Qing-peng Han ◽  
An-lei Zhao ◽  
Jian-xing Ren ◽  
...  
Keyword(s):  
Dynamic Characteristics ◽  
Critical Speed ◽  
Great Influence ◽  
Experimental Platform ◽  
Rotating Machine ◽  
Rotor Bearing ◽  
Before And After ◽  
Analysis System ◽  
The Stability ◽  
Bearing System

Rotor rub-impact has a great influence on the stability and safety of a rotating machine. This study develops a dynamic model of a two-span rotor-bearing system with rubbing faults, and numerical simulation is carried out. Moreover, frictional screws are used to simulate a rubbing state by establishing a set of experimental devices that can simulate rotor-stator friction in the rotor system. Through the experimental platform and its analysis system, the rubbing experiment was conducted, and the vibration of the rotor-bearing system before and after the critical speed is observed. Rotors running under normal condition, local slight rubbing, and severe rubbing throughout the entire cycle are simulated. Dynamic trajectories, frequency spectrum diagrams, chart of axis track, and Poincare maps are used to analyze the features of the rotor-bearing system with rub-impact faults under various parameters. The vibration characteristics of rub impact are obtained. Results show that the dynamic characteristics of the rotor-bearing system are affected by the change in velocity and degree of impact friction. The findings are helpful in further understanding the dynamic characteristics of the rub-impact fault of the two-span rotor-bearing system and provide reference for fault diagnosis.

Improving Rotordynamic Performance of an Axial Flow Compressor With Two-Lobe Bearings Using Nonlinear Constraint Parameter Optimization

2011 ◽  
Author(s):  
Henning Ressing ◽  
Sebastian Kukla
Keyword(s):  
Parameter Optimization ◽  
Dynamic Performance ◽  
Axial Flow ◽  
Rotor Dynamics ◽  
Nonlinear Constraint ◽  
Design Variables ◽  
Rotor Bearing ◽  
Flow Compressor ◽  
Rotor Dynamic ◽  
Bearing System

Bearings are a key factor in achieving a good rotor dynamics performance for turbo machinery. Large compressors, steam and gas turbines for industrial applications are generally equipped with journal bearings either as tilting pad or multi-lobe bearing type. Here bearing parameters such as bearing geometry, bearing load or oil viscosity significantly alter bearing behavior and influence the rotor dynamics of the entire rotor-bearing system. In order to find an optimal set of bearing parameters for a given rotor-bearing system a nonlinear parameter optimization approach is employed. The rotor-bearing system is parameterized using bearing width, clearance and preload as design variables, since they represent design parameters that can be modified without significantly influencing the rotor design as a whole. The set of design variables is further constraint to stay within feasible limits of bearing design. The objective function is defined as a quantitative measure of rotor dynamic performance evaluating the distance from required separation margins with respect to rotor critical speeds based on API 617 7th Ed. In order to compute the objective function based on the design variables the bearing code ALP3T, solving Reynolds equations for the bearing fluid film, is used to compute the required stiffness and damping coefficients as input to the rotor dynamics program. The rotor dynamics performance is then evaluated using the rotor dynamics code SR3 based on the transfer matrix method. Both programs have been developed by the University of Braunschweig and are defacto industry standard within the German turbo machinery industry. The two programs are coupled and the nonlinear constraint optimization problem is solved using MATLAB’s optimization toolbox. The feasibility of this method is discussed based on an example of an axial flow compressor using two-lobe bearings. It is shown that a significant improvement in rotor dynamic performance can be achieved when compared to previous bearing selections for similar compressor designs and that the approach is suitable for a real-life engineering environment.

scholarly journals Improved Immune Genetic Algorithm to Optimize the Design of Wing Structure of Competition Aircraft

2021 ◽  
Vol 2137 (1) ◽  
pp. 012075
Author(s):  
Xi Feng ◽  
Yafeng Zhang
Keyword(s):  
Genetic Algorithm ◽  
Aircraft Design ◽  
Flight Test ◽  
Optimization Methods ◽  
Optimization Method ◽  
Design Parameters ◽  
Immune Genetic Algorithm ◽  
Maximum Deformation ◽  
Design Variables ◽  
Wing Structure

Abstract An improved immune genetic algorithm is used to design and optimize the wing structure parameters of a competition aircraft. According to the requirements of aircraft design, multi-objective optimization index is established. On this basis, the basic steps of using immune algorithm to optimize the main design parameters of aircraft wing structure are proposed, and the optimization of the wing parameters of a competition aircraft is used as an example for simulation calculation. The design variables in the optimization are the size of the wing components, and the optimization goal is to minimize the weight of the wing and the maximum deformation of the wing structure. Research shows that compared with traditional optimization methods; the improved immune genetic algorithm is a very effective optimization method. At the same time, a prototype is made to check the validity and feasibility of the design. Flight test results show that the optimization method is very effective. Although the method is proposed for competition aircraft, it is also applicable to other types of aircraft.

Experimental dynamic analysis of rod-fastening rotor bearing system with a transverse crack

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nanshan Wang ◽  
Heng Liu ◽  
Qidan Wang ◽  
Shemiao Qi ◽  
Yi Liu
Keyword(s):  
Peer Review ◽  
Dynamic Characteristics ◽  
Vibration Amplitude ◽  
Critical Speed ◽  
Transverse Crack ◽  
Content Type ◽  
Rotor Bearing ◽  
Speed Up ◽  
Rod Fastening Rotor ◽  
Bearing System

Purpose This study aims to obtain the dynamic behaviours of cracked rod-fastening rotor bearing system (RFBS), and experimental investigation was carried out to examine the dynamic characteristics of this kind of assembled rotor bearing system with a transverse crack passing through the critical speed. Design/methodology/approach An experimental test rig of cracked RFBS was established for examining the vibration behaviours between intact and cracked system. The crack on the surface of a fastening rod was simulated by wire-electrode cutting processing method. The comprehensive analysis method of vibration was used to obtain the dynamic characteristics such as vibration amplitude, acceleration and whirling orbits before and after the critical speed as well as the instantaneous response in the process of speed up. Findings Some experimental vibration datum is obtained for cracked RFBS. The appearance of a crack will introduce the initial bending and make the vibration amplitude, acceleration and instant response in the process of speed up increase greatly as well as the change of whirling orbits. Originality/value The actual vibration characteristics for this complex assembled rotor system with a transverse crack are given passing through the critical speed. It can provide some useful help for monitoring the vibration behaviours of this kind of assembled rotor system as well as the detection of the crack fault. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-07-2020-0260/

Identification of High-order Critical Speed for Rotor Bearing System

2013 ◽  
Vol 8 (1) ◽  
pp. 346-353
Author(s):  
Yucheng Zhao ◽  
Qiang Fu ◽  
Jianying Zhang
Keyword(s):  
Critical Speed ◽  
High Order ◽  
Rotor Bearing ◽  
Bearing System
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