大展弦比机翼气动弹性分析

发布时间：2018-01-15 08:03

本文关键词：大展弦比机翼气动弹性分析　出处：《沈阳航空航天大学》2017年硕士论文　论文类型：学位论文

【摘要】：本文以大展弦比机翼为研究对象,对机翼静气动弹性和颤振进行了分析,同时研究了大变形对机翼颤振特性的影响。首先,基于经典升力线理论,通过求解力矩平衡方程,计算了大展弦比小后掠角的两种机翼的静气弹扭转:一是对展向结构参数不变的矩形翼,通过直接求解平衡方程,得到了不同飞行条件下机翼的扭转角分布;二是对展向参数变化的梯形翼利用伽辽金法进行求解。该方法可以为机翼初步设计中结构参数的确定提供参考。其次,按照质量、刚度等效原则,建立了某型无人机机翼零平衡位置下的结构有限元模型,通过加载极限飞行载荷,得到了机翼非零平衡位置下的结构模型。对两平衡位置下的机翼结构进行动力学特性分析,通过比较发现,由于大变形,机翼的各阶固有频率相应降低,而且提前出现耦合振型。最后,利用MSC Nastran进行了无人机机翼颤振特性及静气弹发散速度的计算。颤振分析选用PK法,以动力学分析结果为基础,计算了不同条件下机翼的颤振速度和颤振频率。对零平衡位置下的机翼气动力模型进行了不同升力面划分,比较颤振分析结果,发现舵面间隙对机翼颤振速度产生了较大影响;对零平衡位置和非零平衡位置下的机翼进行颤振分析,比较发现结构大变形导致了机翼颤振速度和颤振频率降低。静气弹分析以颤振分析模型为基础,利用颤振法对机翼进行了发散速度计算。
[Abstract]:In this paper, the static Aeroelasticity and flutter of the wing with high aspect ratio are analyzed, and the influence of large deformation on the flutter characteristics of the wing is studied. Firstly, based on the classical lift line theory. By solving the moment balance equation, the hydrostatic elastic torsion of two kinds of wing with large aspect ratio and small sweep angle is calculated. One is the rectangular wing with invariable span structural parameters, and the equilibrium equation is solved directly. The distribution of the wing torsion angle is obtained under different flight conditions. Second, the trapezoidal wing with varying span parameters is solved by Galerkin method, which can provide a reference for the determination of structural parameters in the preliminary design of the wing. Secondly, according to the principle of mass and stiffness equivalence. The finite element model of a certain UAV wing with zero balance position is established, and the ultimate flight load is loaded. The structural model of the wing in non-zero equilibrium position is obtained. The dynamic characteristics of the wing structure in the two equilibrium positions are analyzed. It is found that the natural frequencies of each order of the wing are reduced due to the large deformation. Finally, MSC Nastran is used to calculate the flutter characteristics of UAV wing and the divergence velocity of aerostatic missile. The competition method is used for flutter analysis. Based on the dynamic analysis results, the flutter velocity and flutter frequency of the wing under different conditions are calculated. The aerodynamic model of the wing at zero equilibrium position is divided into different lift surfaces, and the flutter analysis results are compared. It is found that the rudder clearance has a great influence on the flutter velocity of the wing. The flutter analysis of the wing at zero balance position and non-zero balance position shows that the large deformation of the structure results in the reduction of the flutter velocity and flutter frequency of the wing. The hydrostatic elastic analysis is based on the flutter analysis model. The divergence velocity of the wing was calculated by flutter method.
【学位授予单位】：沈阳航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：V211.47

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