Energy Analysis to the Design of Rotor-Bearing Systems

1995 ◽  
Author(s):  
W. J. Chen
Keyword(s):  
Energy Analysis ◽  
Computational Techniques ◽  
Design Strategies ◽  
System Parameters ◽  
Fundamental Properties ◽  
Design Engineers ◽  
Rotor Bearing ◽  
Design Requirements ◽  
Vibration Problems ◽  
Fundamental Physical

In the design of rotating machinery, it is often desirable and necessary to change a subset of system parameters to meet the design requirements. The success in designing rotor bearing systems and/or in solving the vibration problems depends heavily upon the understanding of fundamental physical properties and insights of the systems. The modeling improvements and computational techniques have been extensively presented over the years. The design methodologies and fundamental properties have not been widely addressed to assist design engineers in solving their practical problems. The objective of this paper is to relate the various forms of energy and work and their contributions to the system dynamic characteristics. The design strategies and methodologies using the energy approach are also presented and illustrated in a turbine driven machine.

Energy Analysis to the Design of Rotor-Bearing Systems

1997 ◽  
Vol 119 (2) ◽  
pp. 411-417 ◽  
Author(s):  
W. J. Chen
Keyword(s):  
Energy Analysis ◽  
Computational Techniques ◽  
Design Strategies ◽  
System Parameters ◽  
Fundamental Properties ◽  
Design Engineers ◽  
Rotor Bearing ◽  
Design Requirements ◽  
Vibration Problems ◽  
Fundamental Physical

In the design of rotating machinery, it is often desirable and necessary to change a subset of system parameters to meet the design requirements. The success in designing rotor-bearing systems and in solving the vibration problems depends heavily upon the understanding of fundamental physical properties and insights of the systems. The modeling improvements and computational techniques have been extensively presented over the years. The design methodologies and fundamental properties have not been widely addressed to assist design engineers in solving their practical problems. The objective of this paper is to relate the various forms of energy and work and their contributions to the system dynamic characteristics. The design strategies and methodologies using the energy approach are also presented and illustrated in a turbine-driven machine.

Power Flow and Energy Sharing between an Oscillator and a Continuous Receiver Structure

2011 ◽  
Vol 189-193 ◽  
pp. 1914-1917
Author(s):  
Lin Ji
Keyword(s):  
High Frequency ◽  
Power Flow ◽  
Energy Analysis ◽  
Statistical Energy Analysis ◽  
Coupled Subsystems ◽  
Modal Density ◽  
Vibration Problems ◽  
Energy Sharing ◽  
High Modal Density ◽  
Vibration Modeling

A key assumption of conventional Statistical Energy Analysis (SEA) theory is that, for two coupled subsystems, the transmitted power from one to another is proportional to the energy differences between the mode pairs of the two subsystems. Previous research has shown that such an assumption remains valid if each individual subsystem is of high modal density. This thus limits the successful applications of SEA theory mostly to the regime of high frequency vibration modeling. This paper argues that, under certain coupling conditions, conventional SEA can be extended to solve the mid-frequency vibration problems where systems may consist of both mode-dense and mode-spare subsystems, e.g. ribbed-plates.

A Statistical Approach to Ranking Similarities of Three Function Structure Groups Using Directed Graphs

2018 ◽  
Author(s):  
Briana M. Lucero ◽  
Matthew J. Adams
Keyword(s):  
Statistical Approach ◽  
Directed Graphs ◽  
Proof Of Concept ◽  
Function Structure ◽  
Fundamental Properties ◽  
Design Engineers ◽  
Functional Representation ◽  
Structure Databases ◽  
Further Development ◽  
Function Structures

Prior efforts in the study of engineering design employed various approaches to decompose product design. Design engineers use functional representation, and more precisely function structures, to define a product’s functionality. However, significant barriers remain to objectively quantifying the similarity between two function structures, even for the same product when developed by multiple designers. For function-structure databases this means that function-structures are implicitly categorized leaving the possibility of incorrect categorization and reducing efficacy of returned analogous correlations. Improvements to efficacy in database organization and queries are possible by objectively quantifying the similarity between function structures. The proposed method exploits fundamental properties of function-structures and design taxonomies. We convert function-structures into directed graphs (digraphs) and equivalent adjacency matrices. The conversion maintains the directed (function → flow → function) progression inherent to function-structures and enables the transformation of the function-structure into a standardized graph. For design taxonomies (e.g. D-APPS), graph nodes represent flows in a consistent (but arbitrary) ordering. By exploiting the directional properties of function-structures and defining the flows as the graphical nodes, the objective and standardized comparison of two function-structures becomes feasible. We statistically quantify the association between digraphs using the Pearson Product Moment Correlation (PPMC) for both within-group and between-group comparisons. The method was tested on three product types (ball thrower, food processor, and an ice cream maker) with function-structures defined by various designers. The method suggested herein is provided as a proof-of-concept with suggested verification and validation approaches for further development.

Environmental Design Strategies for Building Egress

2002 ◽  
Vol 46 (9) ◽  
pp. 865-869
Author(s):  
Jake Pauls
Keyword(s):  
Situational Awareness ◽  
World Trade Center ◽  
Environmental Design ◽  
Design Strategies ◽  
Building Evacuation ◽  
Strategic Issues ◽  
Trade Center ◽  
Design Requirements ◽  
The Many ◽  
The Impact

The events of September 2001, 2001, plus the events' technical and political aftermath have helped to identify an unfortunate lack of research into building evacuation. The relative dearth of research is ironic given evacuation's central role in mitigation for a range of emergencies and its prominence in environmental design requirements in building codes and standards. The field of human factors has much to offer, for example, in a philosophical or strategic focus on human-centered design as well in more-prosaic issues such as exit stair width and handrail provision. Much of the available research addresses fairly low-level ergonomic issues such as exit stair width in relation to egress capacity and the impact on evacuation time. in addition to more-sophisticated research into the relatively simple issues, ahead lies more-difficult research relating to strategic issues and the provision of information to building occupants in emergencies, occupants' situational awareness generally, and the many social interactions—in seldom-considered environmental contexts—that are at the heart of major evacuations of large buildings such as in the case of the World Trade Center.

Statistical Energy Analysis of Vibrating Systems

1967 ◽  
Vol 89 (4) ◽  
pp. 626-632 ◽  
Author(s):  
Eric E. Ungar
Keyword(s):  
Complex Systems ◽  
Energy Analysis ◽  
Energy Approach ◽  
Analysis Approach ◽  
Statistical Energy Analysis ◽  
Random Vibrations ◽  
Vibration Problems ◽  
Energy Balances ◽  
Vibrating Systems

The “statistical energy analysis” approach provides a relatively simple means for understanding and estimating the significant properties of multimodal random vibrations of complex systems, since this approach permits one to treat complex vibration problems in terms of much simpler energy balances. This paper delineates the concepts and relations which form the basis for the statistical energy approach, indicates its range of validity, and illustrates some of its applications.

Parametric Study of the Coupling Power Factor for the Statistical Energy Analysis of Piping Acoustic Vibration

2013 ◽  
Author(s):  
Ahmed H. Dweib
Keyword(s):  
Energy Analysis ◽  
Element Model ◽  
Coupling Factor ◽  
Acoustic Energy ◽  
Piping System ◽  
Statistical Energy Analysis ◽  
Multiple Sources ◽  
Pipe Length ◽  
Flow Equations ◽  
System Parameters

Energy-based finite element model is utilized for the evaluation of the Statistical Energy Analysis (SEA) coupling factor and the dependence of the coupling factor on the different system parameters is studied. Previous research has shown that the coupling factor is largely dependent on the modal densities of the fluid and pipe subsystems, which depend on the pipe dimensional parameters. The coupling factor depends also on the spectrum of the acoustic power generated, which in turn depends on the mass flow rate, the pressure reduction ratio and the characteristics of the pressure-reducing device. This study is concerned with the piping system parameters, downstream of the pressure-reducing valve. The system parameters selected for consideration are the pipe diameter to thickness ratio D/T and the pipe length to diameter ratio L/D. The study presents the effect of the variation in these two dimensionless parameters on the coupling factor. The results of the analysis can be used directly in the formulation of SEA power flow equations for large piping systems with multiple sources of acoustic energy as part of the fatigue life evaluation in critical services.

BDS: A Knowledge-Based Bumper Design System

1997 ◽  
Author(s):  
Beverly J. Becker ◽  
Gregory A. Kaepp
Keyword(s):  
Software Design ◽  
Product Performance ◽  
Design System ◽  
Design Knowledge ◽  
Performance Requirement ◽  
Knowledge Based ◽  
Design Engineers ◽  
Design Alternatives ◽  
Design Requirements ◽  
Knowledge Based Engineering

Abstract A knowledge-based Bumper Design System (BDS) has been developed which automatically generates optimized conceptual bumper beams which meet manufacturing and product performance requirement. The BDS has captured and refined the corporate design knowledge of the product design engineer, the CAD designer, the CAE analyst and manufacturer. The BDS enables the bumper design engineers to evaluate multiple design alternatives quickly and early in the design process. It also automates repetitive bumper analysis tasks. The purpose of the paper is to describe the BDS. A description of the Knowledge Based Engineering (KBE) methodology used to create the BDS is given, as well as an overview of bumper designs and design requirements. An overview of the BDS software design, user interface, and a sample run are also presented.

Using Model Uncertainty to Reduce Verification and Validation in Noise and Vibration Problems

2012 ◽  
Author(s):  
Kevin Otto ◽  
Clas Jacobson
Keyword(s):  
Model Uncertainty ◽  
Verification And Validation ◽  
Noise And Vibration ◽  
Uncertainty Range ◽  
Design Changes ◽  
Vehicle Systems ◽  
Occupant Comfort ◽  
Design Requirements ◽  
Vibration Problems ◽  
Residual Errors

Verifying and validating that a mechanical system meets the design requirements is often a costly iterative activity. This is particularity true, for example, with complex vehicle systems that must meet noise and vibration requirements to ensure vehicle occupant comfort. We show here how analysis of model uncertainty can speed verification testing by bounding and guiding hardware prototype redesign. Vibration and acoustic model uncertainty and residual errors are estimated, and then analysis derived to ensure that this uncertainty range is covered by a planned set of design changes. We further use these results to define a complexity metric based on uncertainty, and an adaptability metric based on the domain of available adjustment. We then propose a capability metric by comparing the range of uncertainty against the range of adaptability provided. We demonstrate the efficacy with an example from the elevator system design, rapidly meeting noise and vibration requirements with only one prototype iteration.

scholarly journals Multiphoton quantum-state engineering using conditional measurements

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Omar S. Magaña-Loaiza ◽  
Roberto de J. León-Montiel ◽  
Armando Perez-Leija ◽  
Alfred B. U’Ren ◽  
Chenglong You ◽  
...  
Keyword(s):  
Quantum State ◽  
Light Sources ◽  
Physical Processes ◽  
Quantum State Engineering ◽  
Fundamental Properties ◽  
Statistical Fluctuations ◽  
Squeezed Vacuum ◽  
Vacuum States ◽  
Quantum Phenomena ◽  
Fundamental Physical

Abstract The quantum theory of electromagnetic radiation predicts characteristic statistical fluctuations for light sources as diverse as sunlight, laser radiation, and molecule fluorescence. Indeed, these underlying statistical fluctuations of light are associated with the fundamental physical processes behind their generation. In this contribution, we experimentally demonstrate that the manipulation of the quantum electromagnetic fluctuations of two-mode squeezed vacuum states leads to a family of quantum-correlated multiphoton states with tunable mean photon numbers and degree of correlation. Our technique relies on the use of conditional measurements to engineer the excitation mode of the field through the simultaneous subtraction of photons from two-mode squeezed vacuum states. The experimental generation of nonclassical multiphoton states by means of photon subtraction unveils novel mechanisms to control fundamental properties of light. As a remarkable example, we demonstrate the engineering of a quantum state of light with up to ten photons, exhibiting nearly Poissonian photon statistics, that constitutes an important step towards the generation of entangled lasers. Our technique enables a robust protocol to prepare quantum states with multiple photons in high-dimensional spaces and, as such, it constitutes a novel platform for exploring quantum phenomena in mesoscopic systems.

scholarly journals Natural geometric unit system and electron magnetic moment anomaly

2021 ◽  
Author(s):  
Janusz "Jani" Kowalski
Keyword(s):  
Magnetic Moment ◽  
Research Area ◽  
Charge Ratio ◽  
Electron Mass ◽  
Fundamental Properties ◽  
Unit System ◽  
Powers Of 2 ◽  
Physical Forces ◽  
Electron Magnetic Moment ◽  
Fundamental Physical

Abstract Consequences of implementation of the natural geometric unit system (the SG) based on the pre-2019 SI system, in which four fundamental physical constants undergo joint numerical and dimensional normalization to unity c = G= k = h = 1, with only one base geometric unit u equal to √|h · G/c 3 | m, where the Newtonian gravitational constant G ≈ 6.673 655 205 · 10 -11 m3/(kg · s 2 ), are further explored. In addition to the earlier hypothesized simple electron mass to charge ratio formula me = e/(2 9πα), and formulas for stable quarks rest masses: quark u mu = √(⅔) / (2 7π √(πα)) u, equivalent of 2.360 MeV/c 2 and quark d md = √(⅓) -1 / (2 7π √(πα)) u, equivalent of 5.007 MeV/c 2 , a simple formula for electron magnetic moment anomaly is proposed α/2π - (α/2π) 2 - 2 8 (α/2π) 3 - 2 12 (α/2π) 4 - 2 16 (α/2π) 5 - 2 24 (α/2π) 6 ≈ 0.001 159 652 180. The finding supports the research area of purely geometric modelling of the fundamental physical forces and their unification. It seems plausible, that in the SG, with use of half integer powers of 2, 3, π and α only,all the fundamental properties of stable matter and electromagnetic radiation could be described

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