Masters Theses


Wuu Hao


"This thesis is a theoretical investigation of the effects of intense sound levels and steady flow on the propagation of plane-waves in tubes of constant diameter. The analysis is limited to a study of the change of wave profile due to the intense sound levels, and steady flow. However, corrections for effects of viscous and heat conduction losses at tube walls are also presented. To simplify the analysis, the problem is treated by considering the steady flow and finite-amplitude-sound wave effects separately. For finite-amplitude sound only, two approaches are evaluated. The first uses small perturbations to derive a finite-amplitude wave equation. It is assumed that a velocity potential exists, and that the relationship between acoustic variables in the linear equation also applies to second-order terms. Because of the nature of the nonlinearity of the finite-amplitude wave equation, only an approximate solution is obtained; the solution is, therefore, limited to weak nonlinearities. A second approach, solution by the method of characteristics, is also investigated. Trimmer's investigation of steady flow is presented and discussed. His approach for small amplitude sound waves is extended to the approximate solution obtained for finite amplitude waves. A final correction to account for tube wall losses is also described and presented. Results obtained show that for sound pressure levels up to 140 dB in many practical systems finite amplitude effects are relatively small, but may become significant in the presence of steady flow; tube attenuation reduces finite-amplitude effects, but not significantly for frequencies less than 1000 Hz in tubes greater than 1 in. diameter and less than 5 meters in length"--Abstract, pages ii-iii.


Gatley, William S.

Committee Member(s)

Koval, Leslie Robert
Behr, Christoph G.


Mechanical and Aerospace Engineering

Degree Name

M.S. in Mechanical Engineering


University of Missouri--Rolla

Publication Date



vii, 49 pages


© 1972 Wuu Hao, All rights reserved.

Document Type

Thesis - Open Access

File Type




Subject Headings

Sound-waves -- Mathematical models
Sound-waves -- Attenuation
Sound-waves -- Transmission

Thesis Number

T 2698

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