Experiments on acoustic transport
in thermal turbomachinery
Sound generation, acquisition, and analysis

Abstract: In thermal turbomachinery, reducing sound emissions and preventing failure due to acoustically excited vibrations contribute to the overall goals of improving environmental impact and reliability. The former is particularly important in aircraft engines, while acoustic resonance is less written about but has been a real-life problem in the axial compressors in aircraft engines and stationary gas turbines as well as radial compressors in process applications.

A prerequisite for reducing noise and acoustic resonance is understanding the transport of tonal noise in turbomachines. The lecture covers recent analytical and experimental work on the instrumentation and data analysis for experiments on sound transport in axial turbomachinery. Progress in this area also requires contributions to the generation of synthetic sound fields as well as analytical models for data analysis. Contributions in both areas are reported along with some sensitivity analyses for instrumentation choices and experimental results from an axial turbine. Finally, some recommendations are made for further improvements of the methodology for acoustic research in turbomachinery.