摘要
声爆高精度预测技术是新一代环保型超声速客机设计的核心关键技术之一。基于广义Burgers方程发展了可考虑"大气风"效应的远场高精度预测方法,开发了声爆预测程序"bBoom",并研究了近场声爆信号提取位置和"大气风"对远场声爆计算结果的影响。首先,给出了广义Burgers方程和声爆传播射线的计算方法,重点讨论了方程中计算分子弛豫效应和热黏吸收效应的关键参数。其次,通过简单轴对称构型标模算例、NASA的C25D构型和洛马的LM1021构型等复杂超声速客机算例对所发展的方法进行了验证,表明本文发展的方法在预测远场声爆时具有较高可信度。最后,基于所发展的方法对比了由不同近场提取位置传播到地面的波形,研究了飞机向不同方向飞行时,"大气风"对地面声爆强度和地面影响域的影响。结果表明:对于类C25D标模构型,为了确保远场声爆预测结果具有较高精度,应取机身下方约3倍机身长度位置处的近场压强信号作为传播方程的输入;另外,"大气风"会影响地面声爆强度及地面影响域,在预测时有必要加以考虑。
The high-fidelity sonic-boom prediction is crucial for the design of low-boom supersonic transport aircraft.In this article,a far-field sonic-boom prediction method solving the augmented Burgers equation is studied,and a prediction code called"bBoom"is developed.First,the numerical method for solving augmented Burgers equation and a ray tracing method in propagation are studied.Some significant parameters of molecular relaxation processes and thermoviscous absorption in the Burgers equation are presented.Second,some benchmark cases from the 2 th AIAA Sonic Boom Prediction Workshop,including a simple axi-symmetric body,a NASA low-boom configuration,and LM1021 configuration,are employed to validate the code.The results show that the developed code is accurate and reliable for predicting the far-field waveforms.At last,far-field sonic boom waveforms propagated from different near-field pressure signals at different locations are compared,and the distinction of waveforms in different flight azimuthal angles with atmospheric winds is investigated.It is shown that,in order to improve the accuracy of predicting the sonic boom for configurations like a C25 Dmodel,the near-field signal should be extracted at a distance of three body lengths off the aircraft.It is also shown that atmospheric wind profiles have a significant impact on the sonic-boom waveform and sonic-boom carpet on the ground.
作者
乔建领
韩忠华
丁玉临
池江波
孟冠宇
宋笔锋
宋文萍
QIAO Jianling;HAN Zhonghua;DING Yulin;CHI Jiangbo;MENG Guanyu;SONG Bifeng;SONG Wenping(Supersonic Transport Research Center,School of Aeronautics,Northwestern Polytechnical University,Xi’an 710071,China;Institute of Aerodynamic and Multidisciplinary Design Optimization,School of Aeronautics,Northwestern Polytechnical University,Xi’an 710071,China)
出处
《空气动力学学报》
CSCD
北大核心
2019年第4期663-674,共12页
Acta Aerodynamica Sinica
基金
国家自然科学基金(11772261)
航空科学基金(2016ZA53011)
CFD前沿技术项目(2015-F-016)
关键词
超声速客机
声爆预测
广义BURGERS方程
声射线方法
大气风
supersonic transport
sonic boom prediction
augmented Burgers equation
ray tracing
atmospheric wind profiles
