ACTA AERONAUTICAET ASTRONAUTICA SINICA >
Experimental and Numerical Research on Jet Noise Suppression with Chevron Nozzle for Turbofan Engines
Received date: 2012-06-27
Revised date: 2012-08-16
Online published: 2012-09-21
Supported by
the Fundamental Research Funds for the Central Universities (NZ2012109, NS2013019)
In order to reveal the space distribution of jet noise and suppress it, the unsteady flow field and the jet noise distribution of overall sound pressure level are obtained for various geometric structures of chevron nozzles based on large eddy simulation (LES) and FW-H (Ffowcs Williams-Hawkings) acoustics equation for the separated exhaust systems of turbofan engines. The results show that the stream vortices produced by the chevron is the key for the suppression of the jet noise. An enhanced mixture between the bypass flow and the environment, or between the bypass flow and the core flow, decreases the jet peak velocity. In the range of the geometry parameters of chevron nozzles mentioned in this paper, an exhaust nozzle with chevrons can suppress the jet noise to 154.3 dB as compared with the 159.6 dB of the exhaust system without a chevron nozzle. Meantime, the aerodynamic loss caused by it is only 1.7%. The study thus demonstrates that the chevron nozzle has an active noise suppression function for the separated exhaust system of a turbofan engine.
Key words： turbofan engine; chevron nozzle; jet noise; large eddy simulation; FW-H equation
SHAN Yong , ZHANG Jingzhou , SHAO Wanren , WU Fei . Experimental and Numerical Research on Jet Noise Suppression with Chevron Nozzle for Turbofan Engines[J]. ACTA AERONAUTICAET ASTRONAUTICA SINICA, 2013 , 34(5) : 1046 -1056 . DOI: 10.7527/S1000-6893.2013.0193
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