Investigation of the Combustion Sound and Vibration Characteristics of an Aero-derivative Gas Turbine

The aerospace industry is seeking to utilize alternate fuels in an effort to lower emissions and/or gain independence from foreign fuel supplies. At the time this research was initiated, little work existed in the study of sound and vibration characteristics on the gas turbine using alternative fuels. The sound and vibration energy of a system can indicate its operating health, and provide information to optimize the system. Excessive levels of sound and vibration can lead to premature failure of components, and impose discomfort to nearby personnel. Alternative Fischer Tropsch fuels, S-8 and IPK, and conventional fuel Jet A, were used in the research gas turbine engine. The sound and vibration characteristics for each operation were investigated, and IPK exhibited slightly higher levels than Jet A. When sound levels exceed a desired level, typically the most feasible approach to noise control is to implement acoustically absorbent material in the acoustic path. Another means to reduce the carbon footprint is to incorporate green materials in noise control applications. A soy based sound absorbing foam was investigated and compared to the performance of the melamine. The soy based material outperformed melamine in the high frequency range