ATTENUATION of FJ44 TURBOFAN ENGINE NOISE with a FOAM-METAL LINER INSTALLED OVER-the-ROTOR

摘要

A Williams International FJ44-3A 3000-Ib thrust class turbofan engine was used as a demonstrator for a foam-metal liner installed in close proximity to the fan. Two foam-metal liner designs were tested and compared to the hardwall baseline. Traditional Single-Degree-of-Freedom liner designs were also evaluated to provide a comparison. Farfield acoustic levels and limited engine performance results are presented in this paper. The results show that the foam-metal liner achieved up to 5 dB PWL overall attenuation in the forward quadrant, equivalent to the traditional liner design. An earlier report presented the test set-up and conditions.