Accession Number : ADA020105

Title :   The Effects of Simple Boundary Irregularities on Acoustical Mode Propagation in Ducts with Pressure Release Boundaries.

Descriptive Note : Master's thesis,


Personal Author(s) : DA Silva Nunes,Luis Fernando Pereira

Report Date : DEC 1975

Pagination or Media Count : 48

Abstract : Effects of boundary irregularities on acoustical mode propagation in ducts, with pressure release walls are theoretically studied. Several particular wall irregularities are explored: sinusoidal, delta-function and spatially decaying wall perturbations. Strong effects (resonances) appear in the case of the sinusoidal wall. In the other two cases, the resonances are not present, but there are still traveling disturbances whose effects can be important at great distances from the wall irregularity.

Descriptors :   *Acoustic waves, *Wave propagation, *Ducts, Waveguides, Boundaries, Walls, Perturbations, Mathematical analysis, Wave equations, Problem solving, Theses, Surface properties

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE