考虑配平特性的超声速客机低声爆气动布局优化研究

降低声爆水平是下一代超声速运输机研制需要解决的关键问题之一。低声爆优化通常使飞行器布局向着机翼后掠角增大、机翼沿机身方向分布范围增大的趋势发展，给飞行器的配平和低速特性带来不利影响。以某超声速客机基本构型为研究对象，建立基于类别/形状函数的翼身组合体参数化建模方法；基于超声速线化理论分析外形几何参数对声爆水平的影响。在此基础上，分别针对机身轮廓、机翼平面形状以及扭转角分布对该构型进行低声爆优化和俯仰力矩特性优化，并采用CFD 方法对优化结果进行校核。结果表明：与基准构型相比，在不显著增加俯仰力矩的基础上，优化构型的阻力降低了19 cts，近场过压显著降低，地面声爆响度降低5.1 PLdB。

The low sonic boom and aerodynamic optimization of supersonic jet

The abatement of sonic boom noise level is a decisive issue for supersonic transport of next generation. The low sonic boom optimization always make the configuration to a trend of higher swept and longer distribution of the wing along the fuselage, which is unfavorable to the trim and low speed characteristics. A civil supersonic transport was researched in this paper. A parametric geometry representation method based on class function/shape function transformation(CST) was developed to describe the wing body configuration. The effects of geometry parameters on sonic boom was analyzed by supersonic linearized theory. Based on the above work, the low sonic boom and pitch moment characteristics optimization were taken for the fuselage, wing planform and twists separately and the optimal result was validated by CFD. The numerical simulation results show that compared with the basic configuration, the drag decrease 19 cts (unit of drag coefficient) and the over pressure at near-field is abated obviously without the distinct increase of pitch moment, which bring 5.1 PLdB reduction of loudness on the ground.