民机概念设计阶段的气动弹性优化设计

AEROELASTIC OPTIMIZATION DESIGN OF CIVIL AIRCRAFT AT CONCEPTUAL DESIGN STAGE

针对民机气动弹性问题,进行概念设计阶段的气动弹性优化设计,尽量避免因气动弹性导致后续的设计更改甚至重新设计.以某大展弦比机翼为例,参照同类飞机初步确定结构刚度分布,并以结构重量最小化为优化目标,以颤振速度、最大变形、最大应力、发散速度的限制为约束条件,利用优化迭代方法进行气动弹性求解.结果表明,在给定的约束条件下,机翼的颤振速度满足气动弹性稳定性要求,且强度、刚度和静发散特性也都满足设计要求;同时,根据优化求解结果得到了机翼的刚度分布指标.研究结果为民机概念设计阶段的结构布局提供了依据.

For aeroelastic problems of civil aircraft,optimization design at the conceptual design stage is carried out to avoid subsequent design alteration or even redesign. Taking a high aspect ratio wing as an example,structural stiffness distribution is preliminarily determined by referring to similar aircrafts,and structural weight is minimized as the optimization objective. Adopting limit flutter speed,maximum deformation of wing tip,maximum stress of wing root and divergence speed as the constraint conditions,aeroelasticity problem of the wing is solved by using the optimization iteration method. Results demonstrate that under the given constraints,flutter speed of the wing meets the flutter stability requirement,and the strength,stiffness and static divergence characteristics also meet the design requirements. And according to the optimization results,stiffness distribution indexes along the wing span are obtained,which provides guidance for the structural layout of civil aircraft at the conceptual design stage.