A Study of the Nonlinear Acoustic Response of Area-contractions and Sense-lines
Metadata Field | Value | Language |
---|---|---|
dc.contributor.advisor | Scarborough, David | |
dc.contributor.author | Teasley, Thomas | |
dc.date.accessioned | 2017-12-08T19:29:36Z | |
dc.date.available | 2017-12-08T19:29:36Z | |
dc.date.issued | 2017-12-08 | |
dc.identifier.uri | http://hdl.handle.net/10415/6058 | |
dc.description.abstract | Rocket and gas turbine engine combustion instabilities, which lead to rapid engine failure through enhanced heat transfer rates and high-cycle fatigue, continue to be a serious concern for engineers. Experimental pressure measurements remain the best approach in determining the susceptibility of an engine to acoustically coupled combustion instabilities. However, the harsh, high-temperature environment requires that pressure transducers be remotely mounted to the engine's main chamber using “sense-lines”, creating an area-contraction at the connection point between the sense-line and combustor. Preliminary measurements have shown large discrepancies between sense-line measured and engine pressure amplitudes. To elucidate these discrepancies, this experimental study measured the nonlinear acoustic response of the area-contraction and sense-line with and without purge air flow. To do this, a multiple-microphone impedance tube was used to measure the acoustic impedance of the combined area-contraction and sense-line. Measurements were performed over a range of frequencies, area-contraction ratios, acoustic velocity amplitudes, and sense-line length-to-diameter ratios. These measurements revealed the acoustic response of the sense-line and area-contraction combination is highly nonlinear. | en_US |
dc.subject | Aerospace Engineering | en_US |
dc.title | A Study of the Nonlinear Acoustic Response of Area-contractions and Sense-lines | en_US |
dc.type | Master's Thesis | en_US |
dc.embargo.status | NOT_EMBARGOED | en_US |
dc.contributor.committee | Thurow, Brian | |
dc.contributor.committee | Hartfield, Roy |