Acoustic Tomography and Thrust Estimation on Turbofan Engines

Acoustic sensing provides a possibility of measuring propulsion flow fields non-intrusively, and is of great interest because it may be applicable to cases that are difficult to measure with traditional methods. In this work, some of the successes and limitations of this technique are considered. In the first main result, the acoustic time of flight is shown to be usable along with a calibration curve in order to accurately estimate the thrust of two turbofan engines (1.0-1.5%). In the second, it is shown that acoustic tomography methods that only use the first ray paths to arrive cannot distinguish some relevant propulsion flow fields (i.e., different flow fields can have the same times of flight). In the third result we demonstrate, via the first validated acoustic tomography experiment on a turbofan engine, that a reasonable estimate of the flow can be produced despite this challenge. This is also the first successful use of acoustic tomography to reconstruct a compressible, multi-stream flow.

Name thesis:degree_name

Doctor of Philosophy

Level thesis:degree_level

doctoral

Discipline thesis:degree_discipline

Aerospace Engineering

Department dc:contributor.department

Aerospace and Ocean Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2023

Author dc:creator

• Gillespie, John Lawrie

Chairs dc:contributor.committeechair

• Lowe, K. Todd
• Ng, Wing Fai

Committee members dc:contributor.committeemember

• Kapania, Rakesh K.
• Devenport, William J.

• Acoustic Tomography
• Jet Engines
• Compressible Flow
• Inverse Problems

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Language dc:language.iso

en

Dc Identifier Other

vt_gsexam:39236

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/117267