基于增广Burgers方程的超声速客机远场声爆预测研究

Research on Far-field Acoustic Explosion Prediction of Supersonic Aircraft Based on Augmented Burgers Equation

声爆问题是限制超声速客机投入使用的巨大阻碍,精确的声爆预测方法是解决超声速客机声爆问题的关键。声爆远场预测方法主要有波形参数法和增广Burgers方程法,相较于波形参数法,增广Burgers方程法有更完善的模型和更高的预测精度。本文首先对增广Burgers方程求解,提出一种有效的非线性效应求解方法;然后基于算子分裂法构建声爆远场预测方法,利用第二届国际声爆研讨会的标准算例对该方法进行验证;最后分析时间、空间网格密度和缓冲信号对预测结果的影响。结果表明:基于Burgers方程的声爆求解方法不需要时间、空间网格达到收敛所需的网格密度,而是按照实际精度需求选取适当网格密度;缓冲信号的引入对于大型超声速飞机的声爆预测更加准确。

The sonic boom problem is a great barrier to the application of supersonic aircraft,and the accurate sonic boom prediction method is the key of the sonic boom problem.Waveform parameter method and augmented Burgers equation method are frequently used for the sonic boom prediction.Compared with the waveform parameter method,the augmented Burgers equation method has more complicated model and higher prediction accuracy.To solve the augmented Burgers equation,an effective nonlinear effect solving method is put forward.A far-field sonic boom signature prediction method based on operator splitting method is established,and verified with examples provided by Second Sonic Boom Prediction Workshop(SBPW-2).The influence of time,space grid density and buffer signal on prediction results are analyzed.The results show that it is unnecessary for the sonic boom solving method to get the required grid density while time and space grid is converged,but to select the suitable grid density according to practical accuracy demand.The buffer signature does not seem to be necessary for small aircraft such as corporate ones,but for bigger aircraft the buffer signature is essential.