2018/5/16 Aircraft Noise Source Breakdown 园上声克大学 Aircraft Noise Sources -airframe noise 国上活大学 ·Primary Noise Sources Landing gear Slotted slat Flap side-edges Ref:ESDU 02020 APPROACH(long range aircraft) APPROACH(short range aircraft) cavities Flat/slat tracks and slat track cut-outs Spoilers Gear-wake/flap interactions Ref:222 Source:Airbus Ref noise222 Aircraft Noise Sources-engine noise 圈上活大坐 Representation of Aircraft Gas Turbine Noise 园上活道大整 Different engine types Turbofan turbojet High Bypass Ratio 8oa6ooT2四- Estimation Methods for Aircraft Noise 国上清大学 Empirical Noise Calulation 图上活大坐 Empirical methods Fink method(1976,ANOPP)with update recently -Based on experimental data(wind tunnel/flight tests) -Represents early effort to estimate noise using empirical -Fast.but less accurate methods -Only applicable to certain configurations Available in public domain Experiments Guo method (Boeing) -Used for certification process -Derived from a large database of phased array measurement -Costly,time-consuming -Can relate to certain design features of the airplane -Used for validation of methods Incorporated into ANOPP Computational methods(CAA,Computational Aeroacoustics) -Issues with applications to different configurations,proprietary -Developed over the last couple of decades,the focus ESDU method(UK) -Closely related to CFD -In the public domain,validated,software available for use -Computationally expensive -Has the potential for wider use in design process Onlybageometres and correlations ith parameters Large amount of wind tunnel tests necessary to build credibie methods slty-Dr.V(enbin Song 42018/5/16 4 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Aircraft Noise Source Breakdown Ref: noise222 Ref: ESDU 02020 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Aircraft Noise Sources – airframe noise • Primary Noise Sources – Landing gear – Slotted slat – Flap side-edges and slat side￾edges including cavities – Flat/slat tracks and slat track cut-outs – Spoilers – Gear-wake/flap interactions Ref: 222 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Aircraft Noise Sources – engine noise © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Representation of Aircraft Gas Turbine Noise • Different engine types turbojet Low Bypass Ratio Turbofan High Bypass Ratio Turbofan © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Estimation Methods for Aircraft Noise • Empirical methods – Based on experimental data (wind tunnel/flight tests) – Fast, but less accurate – Only applicable to certain configurations • Experiments – Used for certification process – Costly, time-consuming – Used for validation of methods • Computational methods (CAA, Computational Aeroacoustics) – Developed over the last couple of decades, the focus – Closely related to CFD – Computationally expensive – Has the potential for wider use in design process © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics Empirical Noise Calulation • Fink method (1976, ANOPP) with update recently – Represents early effort to estimate noise using empirical methods – Available in public domain • Guo method (Boeing) – Derived from a large database of phased array measurement – Can relate to certain design features of the airplane – Incorporated into ANOPP – Issues with applications to different configurations, proprietary • ESDU method (UK) – In the public domain, validated, software available for use – Only cover basic geometries and correlations with parameters not strong • Large amount of wind tunnel tests necessary to build credible methods