Vibration Analysis of Rotor-Fluid Film Bearing System Using Monte Carlo Method

2010 ◽  
Author(s):  
Zhengkai Zhang ◽  
Youyun Zhang ◽  
Yongsheng Zhu
Keyword(s):  
Monte Carlo ◽  
Vibration Analysis ◽  
Monte Carlo Analysis ◽  
Working Environment ◽  
Fluid Film ◽  
Design Parameters ◽  
Rotor Vibration ◽  
Design And Manufacturing ◽  
Manufacturing Tolerances ◽  
Bearing System

The rotor-fluid film bearing systems are widely used in machinery due to their small size, low price, and capability of carrying load. However, if its design and manufacturing is inappropriate, the use of rotor-fluid film bearing system will suffers from some problem such as violent vibration. Although the checking calculation has been carried out during the design process, nominal value of design parameters is usual used to prognosis the vibration characteristics of rotor-fluid film bearing system. However, in practice, these parameters always vary within a certain range due to manufacturing tolerances and variation of working environment. In this paper, a model for simulating the performance of rotor-fluid film bearing system has been established. Monte Carlo analysis was performed to evaluate the effects of manufacturing tolerances and variation of working environment on the rotor vibration. In the end, a uncertainty analysis is carried out to demonstrate which of the factors has the greatest effect on the rotor vibration at different rotational speed.

Monte Carlo Analysis Techniques Revisited

1998 ◽  
Author(s):  
K. Suresh
Keyword(s):  
Monte Carlo ◽  
Engineering Design ◽  
Monte Carlo Analysis ◽  
Boundary Element Methods ◽  
Design Parameters ◽  
Check Point ◽  
Engineering Analysis ◽  
Analysis Techniques ◽  
Early Stages ◽  
Point Analysis

Abstract The predominant engineering analysis techniques are the finite element, finite difference and boundary element methods. These techniques are global in that they attempt to solve field problems over an entire domain. Global techniques are, however, an ‘over-kill’ in the early stages of engineering design, when design parameters are fuzzy, and the functional viability of options can be determined through quick check-point analysis. In this paper, we revisit two ‘discarded’ Monte Carlo (MC) analysis techniques: MC boundary sampling, and MC domain sampling, which can be employed for solving field problems at discrete points. These techniques can be (potentially) more effective than global techniques, especially in the early stages of engineering design, but are ignored in practice because they are computationally expensive if implemented conventionally. In this paper, we argue that an appropriate geometric representation (of the underlying domain) — specifically, ray-representations for boundary sampling, and Voronoi graphs for domain sampling — is critical for efficient implementation of each technique. Exemplary numerical results are also presented.

Effect of Manufacturing Tolerances on Stiffness and Damping of Hydrodynamic Journal Bearings

2010 ◽  
Vol 139-141 ◽  
pp. 2662-2667
Author(s):  
Wu Bin Xu ◽  
Peter J. Ogrodnik ◽  
Mike J. Goodwin ◽  
Gordon Bancroft
Keyword(s):  
Journal Bearing ◽  
Design Stage ◽  
Design Parameters ◽  
Damping Characteristics ◽  
Theoretical Predictions ◽  
Bearing Stiffness ◽  
Manufacturing Tolerances ◽  
Hydrodynamic Journal Bearing ◽  
Stiffness And Damping ◽  
Bearing System

From a manufacturing viewpoint, the manufacturing tolerances of a hydrodynamic journal bearing system are inevitable. To examine and understand the effect of manufacturing tolerances on dynamic characteristics of a hydrodynamic journal bearing system can help engineers to confidently choose reasonable tolerances at design stage or to enable the system with certain manufacturing tolerances to operate closer to the theoretical predictions. This study presented a theoretical analysis method to determine and demonstrate the effect of manufacturing tolerances on bearing stiffness and damping, in which the concepts of limits, tolerances and nominal dimensions are introduced in. The results show that the manufacturing tolerances of a hydrodynamic journal bearing system have profound influences on the bearing stiffness and damping, and the magnitude of effect depends on system design parameters in the form of Sommerfeld number. The presented method will better predict system stiffness and damping characteristics.

scholarly journals Monte Carlo analysis of beam blocking grid design parameters: Scatter estimation and the importance of electron backscatter

2018 ◽  
Vol 45 (3) ◽  
pp. 1059-1070 ◽  
Author(s):  
Gregory J. Bootsma ◽  
Lei Ren ◽  
Hong Zhang ◽  
Jian-Yue Jin ◽  
David A. Jaffray
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Analysis ◽  
Design Parameters ◽  
Electron Backscatter ◽  
Grid Design

Generation of Correlated Logistic-Normal Random Variates for Medical Decision Trees

1998 ◽  
Vol 37 (03) ◽  
pp. 235-238 ◽  
Author(s):  
M. El-Taha ◽  
D. E. Clark
Keyword(s):  
Monte Carlo ◽  
Decision Trees ◽  
Computer Algebra ◽  
Taylor Series ◽  
Computer Algebra System ◽  
Random Variable ◽  
Monte Carlo Analysis ◽  
Normal Random Variable ◽  
Medical Decision ◽  
Theoretical Results

AbstractA Logistic-Normal random variable (Y) is obtained from a Normal random variable (X) by the relation Y = (ex)/(1 + ex). In Monte-Carlo analysis of decision trees, Logistic-Normal random variates may be used to model the branching probabilities. In some cases, the probabilities to be modeled may not be independent, and a method for generating correlated Logistic-Normal random variates would be useful. A technique for generating correlated Normal random variates has been previously described. Using Taylor Series approximations and the algebraic definitions of variance and covariance, we describe methods for estimating the means, variances, and covariances of Normal random variates which, after translation using the above formula, will result in Logistic-Normal random variates having approximately the desired means, variances, and covariances. Multiple simulations of the method using the Mathematica computer algebra system show satisfactory agreement with the theoretical results.

Monte Carlo Analysis of Nonequilibrium Ionized Flows.

1996 ◽  
Author(s):  
Iain D. Boyd ◽  
Xiaoming Liu ◽  
Jitendra Balakrishnan
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Analysis

scholarly journals Li-ion batteries for peak shaving, price arbitrage, and photovoltaic self-consumption in commercial buildings: A Monte Carlo Analysis

2021 ◽  
Vol 234 ◽  
pp. 113889
Author(s):  
Pietro Elia Campana ◽  
Luca Cioccolanti ◽  
Baptiste François ◽  
Jakub Jurasz ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Analysis ◽  
Commercial Buildings ◽  
Li Ion Batteries ◽  
Peak Shaving ◽  
Li Ion
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