Noise Radiation From A Cylindrical Embossment Immersed In Turbulent Boundary Layer Flow.Report as inadecuate

 Noise Radiation From A Cylindrical Embossment Immersed In Turbulent Boundary Layer Flow.

Noise Radiation From A Cylindrical Embossment Immersed In Turbulent Boundary Layer Flow. - Download this document for free, or read online. Document in PDF available to download.

Type of Resource: text

Genre: Electronic Thesis or Dissertation

Date Created: Fall 2015

Date Issued: 2015

Publisher: Florida Atlantic University

Physical Form: pdf

Extent: 145 p.

Language(s): English

Summary: This dissertation will consider the sound radiation from forward-facing steps and a three dimensional cylindrical embossment of very low aspect ratio mounted on a plate. Glegg et al (2014) outlined a theory for predicting the sound radiation from separated flows and applied the method to predicting the sound from forward-facing steps. In order to validate this theory it has been applied to the results of Catlett et al (2014) and Ji and Wang (2010). This validation study revealed that the original theory could be adjusted to include a mixed scaling which gives a better prediction. RANS simulations have been performed and used to support the similarities between the forward-facing step and the cylindrical embossment. The simulations revealed that the cylindrical embossment exhibits a separation zone similar to that of the forward-facing step. This separation zone has been shown to be the dominant source of noise on the forward-facing step in previous works and therefore was expected to be the major source of sound from the cylindrical embossment. The sensitivity of this separation zone to the different parameters of the flow has been investigated by performing several simulations with different conditions and geometries. The separation zone was seen to be independent of Reynolds number based on boundary layer thickness but was directly dependent on the height of the cylinder. The theory outlined in Glegg et al (2014) was then reformulated for use with a cylindrical embossment and the predictions have been compared with wind tunnel measurements. The final predictions show good agreement with the wind tunnel measurements and the far-field sound shows a clearly defined directionality that is similar to an axial dipole at low frequencies.

Identifier: FA00004484 (IID)

Note(s): Includes bibliography.Dissertation (Ph.D.)--Florida Atlantic University, 2015.

Held by: Florida Atlantic University Digital Library

Sublocation: Boca Raton, Fla.

Persistent Link to This Record:

Restrictions on Access: All rights reserved by the source institution

Owner Institution: FAU

Author: Bryan, Benjamin Skyler, author Glegg, Stewart Dr., Thesis advisor College of Engineering and Computer Science, Degree grantor



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