Jet Noise Suppression with Fan Flow Deflectors in Realistic-shaped Nozzle
نویسندگان
چکیده
This is an exploratory study of jet noise reduction using fan flow deflectors in a nozzle shaped like the exhaust of a separate-flow turbofan engine with bypass ratio 4.8. The deflectors directed the bypass plume downward and/or sideward relative to the core plume. Vaneand wedge-type deflectors were tested. The noise reduction achieved by the vane deflector was strong in the downward direction and moderate in the sideline direction. Wedge-type deflectors generated significant attenuation in both directions. Combination of vanes and wedge yielded the best results. The effective perceived noise level was suppressed by 5.5 dB in flyover mode and 3.8 dB in sideline mode.
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