Development and validation of a measurment procedure to determine the radiated sound power of a radial compressor
Acoustics
Fluid Mechanics
Final Report Abstract
This project extends “Acoustic emission into discharge pipes”. The primary goal of this project was to develop an efficient, robust, flexible applicable and low-cost acoustic measurement system and to validate it experimentally. The requirement of this measurement system is to determine the in-duct sound power level emitted by a radial compressor with vaned and vaneless diffuser designs into the discharge pipe. Unlike costly rotary pipe sections, this measurement system is based on a simplified design using a low sensor count resulting in a low-cost acoustic measurement pipe section. The goal of the requested follow-up project phase is to conduct extensive experiments with two newly introduced measurement techniques for verification purposes. One approach relies on efficient Azimuthal Mode Analysis using Compressed Sensing algorithms that are combined with a Radial Mode Amplitude energy distribution model (EEDM). The second approach relies on a Radial Compressor Equivalent Tonal noise source model (RACET) that simulates the noise emissions into the discharge pipe using an appropriate analytical model. The introduced measurement techniques are tested on stochastic simulated in-duct pressure measurements to ensure their accuracy and robustness over the radial compressor relevant broad analysis frequency range. With the aid of the newly developed and tested measurement system, turbomachine manufacturers and operators will be able to determine the sound field emitted by radial compressors over the complete engine map. In future, low-noise radial compressor designs can be assessed. Additionally, secondary noise control techniques can be evaluated. Finally, numerical simulations are extended for the industrial case of vaned diffusers, which will provide reference solutions for future projects. The overall objective of the research project was achieved.
