Masters Theses

Abstract

"Noise of claw pole alternators, generated electromagnetically and structurally radiated, has been the subject of an extensive research program. The goal has been to identify and reduce noise radiation mechanisms in claw pole (Lundell) alternators used in automotive applications. The study reported here has investigated machine and mount response to electromagnetically generated torque ripple. Modeling and experimentation has led to the conclusion that there exists a high correlation between electromagnetic sources, torque ripple, and radiated noise. Experimentation also has led to the conclusion that noise characteristics of a given machine are substantially altered by modification of the mounting configuration. The work reported here involves modeling, simulation, and experiment to isolate machine dynamic characteristics and mounting geometries which contribute to strong coupling between torque ripple and machine/mount dynamic response. A low order model of the alternator which includes shaft flexibility, gyroscopic effects, shaft bearing asymmetry, mounting lug geometry, and mounting structure dynamics has been created. The model provides a rapid simulation of dynamic response in the form of a transfer function between torque ripple and mounting forces. Electromagnetic modeling and dynamic response simulations suggest that the six phase machine is inherently quieter. This is supported by experimental results. A test fixture for the measurement of torque ripple has been developed. Experimentation shows that the relative amplitudes of torque ripple in three and six phase machines correlates with relative noise levels. In addition, in torque ripple measurements, machine mounting characteristics are substantially altered and a predictably large reduction in radiated noise is realized"--Abstract, page iv.

Advisor(s)

Eversman, Walter

Committee Member(s)

Dharani, Lokeswarappa R.
Crow, Mariesa

Department(s)

Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering

Comments

Financial support has been provided by Delphi Automotive Systems, as well as the Integrative Graduate Education and Research Training (IGERT) program, which is funded by the National Science Foundation.

Publisher

University of Missouri--Rolla

Publication Date

Spring 2004

Pagination

ix, 54 pages

Note about bibliography

Includes bibliographical references (page 38).

Rights

© 2004 Steven Jonathan Burns, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Subject Headings

Automobiles -- Electric generators -- Design and construction
Automobiles -- Noise
Noise control

Thesis Number

T 8511

Print OCLC #

56586277

Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

http://merlin.lib.umsystem.edu/record=b5129916~S5

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