Song Chiou

ACOUSTIC INSERTION LOSS MEASUREMENT OF HQ-TUBE LINER

A new advanced passive acoustic liner system for large turbofan engines is presented. The passive system consists of the integration of traditional single-layer liners with multiple arrays of Herschel-Quincke waveguides, i.e. HQ-liner concept. This system has the potential of offering superior noise reduction capability for a large turbofan engine inlet with reduced cost and weight over the current multi-layer liner structures. The main goal of this work is to experimentally demonstrate the HQ-liner’s ability to attenuate noise in the acoustic/flow environment found in real systems. To this end, multiple configurations of HQ-liner systems were tested in a rectangular duct under high intensity noise and high grazing flow. This work summarizes the acoustic insertion loss measurement test results for the HQ-tube liner. The development and validation of HQ-liner models are also underway and will be reported in the near future.