论文部分内容阅读
为了更加有效地减小民用客机考虑配平约束后的阻力,针对典型跨声速民用客机机翼-机身-平尾构型研究了不同静稳定度下的气动优化设计,并总结出在民用客机的减阻设计中考虑放宽静稳定度具有较大的减阻潜力。通过自由型面变形(FFD)技术对全机外形进行参数化,实现机翼型面的变形,进行气动优化设计并改变平尾的偏转保证全机能够力矩配平。采用基于雷诺平均Navier-Stokes(RANS)方程的离散伴随方法求解目标函数对设计变量的梯度,然后基于序列二次规划算法进行基于梯度的气动优化设计。基于CRM(Common Research Model)构型,针对不同参考重心位置进行了考虑配平约束的减阻优化设计研究,验证了优化设计系统的有效性,算例结果表明,随着重心位置后移即放宽静稳定度,优化构型配平阻力减小,外翼段前缘吸力峰值明显降低且双激波的强度得到有效减弱,此外机翼的升力系数分布更加贴合最佳升力系数分布。
In order to reduce the resistance of civil passenger aircraft more effectively, the aerodynamic optimization design under different static stability is studied for the typical transonic civil aircraft wing-fuselage-tail-end configuration. The conclusions are drawn as follows: Resistance design to consider the relaxation of static stability has a greater drag reduction potential. Freeform surface deformation (FFD) technology is used to parameterize the shape of the whole machine to realize the deformation of the airfoil. Optimize the aerodynamic design and change the deflection of the horizontal tail to ensure that the whole machine can be torque balanced. A discrete adjoint method based on the Reynolds-averaged Navier-Stokes (RANS) equation was used to solve the gradient of the objective function versus the design variables. Then a gradient-based aerodynamic optimization design based on quadratic programming algorithm was proposed. Based on the Common Research Model (CRM) configuration, the drag reduction optimization design considering the trim constraint is studied for different reference centers of gravity, and the validity of the system is verified. The results show that as the center of gravity shifts backwards, The stability and the optimal configuration trim resistance decrease, the suction peak value at the leading edge of the outer wing segment decreases significantly and the strength of the double shock wave is effectively weakened. In addition, the lift coefficient distribution of the wing more closely matches the optimal lift coefficient distribution.