飞机静压系统导管内径的优选

推导出静压系统迟滞指标植与结构参数的关系式，指出减小迟滞指标值的最有措施是增大导管的内径。同时阐述了迟滞的成因及其对飞机的负效应。     

STUDY OF THE SOLID MODELINGTECHNIQUES ADAPTIVE TOPRODUCT MODELING

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Reachable set modeling and engagement analysis of exoatmospheric interceptor

A novel reachable set(RS) model is developed within a framework of exoatmospheric interceptor engagement analysis. The boost phase steering scheme and trajectory distortion mechanism of the interceptor are firstly explored. A mathematical model of the distorted RS is then formulated through a dimension–reduction analysis. By treating the outer boundary of the RS on sphere surface as a spherical convex hull, two relevant theorems are proposed and the RS envelope is depicted by the computational geometry theory. Based on RS model, the algorithms of intercept window analysis and launch parameters determination are proposed, and numerical simulations are carried out for interceptors with different energy or launch points. Results show that the proposed method can avoid intensive on-line computation and provide an accurate and effective approach for interceptor engagement analysis. The suggested RS model also serves as a ready reference to other related problems such as interceptor effectiveness evaluation and platform disposition.     

Analysis of optimal initial glide conditions for hypersonic glide vehicles

Hypersonic glide vehicles （HGVs） are launched by a solid booster and glide through the atmosphere at high speeds. HGVs will be important means for rapid long-range delivery in the future. Given that the glide is unpowered, the initial glide conditions （IGCs） are crucial for flight. This paper aims to find the optimal IGCs to improve the maneuverability and decrease the con- straints of HGVs. By considering the IGCs as experiment factors, we design an orthogonal table with three factors that have five levels each by using the orthogonal experimental design method. Thereafter, we apply the Gauss pseudospectral method to perform glide trajectory optimization by using each test of the orthogonal table as the initial condition. Based on the analytic hierarchy process, an integrated indicator is established to evaluate the IGCs, which synthesizes the indexes of the maneuverability and constraints. The integrated indicator is calculated from the trajectory opti- mization results. Finally, optimal IGCs and valuable conclusions are obtained by using range anal- ysis, variance analysis, and regression analysis on the integrated indicator.     

民用飞机外翼中央翼对接面位置的研究

机翼对接设计是飞机结构设计的一个重要环节,而机翼对接面位置的选择对对接结构的设计有重要影响。基于客机外翼与中央翼的对接面,分析各种对接面位置对对接结构设计的影响,比较其中的优缺点;分析了修形面和其相对于机身等直段的变形量;并提出一种新型对接面位置,为民用飞机外翼中央翼对接的对接面设计提供一种选择。     

民用飞机外翼中央翼对接肋腹板选型研究

典型民用飞机外翼中央翼是通过对接肋完成对接的,对接肋的腹板在其中起到重要的传递载荷和支持结构的作用。随着制造技术的发展,先进的民用飞机上出现了整体加筋式的腹板,这有别于传统的组合式加筋的腹板结构。利用商业有限元软件Hyperworks研究在压剪复合载荷并均匀油压载荷下,这两种加强筋类型腹板在变形、局部失稳、整体失稳和破坏下的承载能力,得出了较好的加强筋形式。最后分析针对两种类型腹板的压剪复合加载试验,验证了软件的仿真分析,为关键连接区的零件设计提供方法支持。     

飞机结构中凹陷应力集中系数初步确定

在飞机生产和使用过程中,由于某些原因,结构可能出现凹陷损伤,为了保障飞机的飞行安全,有必要对凹陷进行疲劳分析,从而确定凹陷是否满足疲劳要求。本文主要对凹陷疲劳分析时所用的应力集中系数进行了初步的确定。     

焊接方式对铝合金搅拌摩擦焊T 型接头性能的影响

采用4种规格的搅拌头进行了2A70-T6铝合金T型接头搅拌摩擦焊试验,并对焊缝横截面进行了观察以及焊缝抗拉强度的测试.结果表明:焊缝中前进侧熔合过渡区的金属变形比返回侧剧烈,焊缝断裂往往发生在前进侧;在相同的焊接参数下,单道焊缝的焊核宽度与抗拉强度随着搅拌针直径的增大而增大,但增大的幅度较小,并列焊的焊缝抗拉强度仅为单道焊缝的93％左右;为了获取相同宽度的焊核,采用加粗搅拌针单道焊比并列焊更具有优势.     

倾斜射流撞壁实验研究及液膜几何参数建模

倾斜射流撞壁在液体火箭发动机液膜冷却、射流撞壁雾化等领域具有广泛的应用。为了研究倾斜射流撞击壁面后形成的液膜的关键特征，开展单股圆柱射流撞击壁面的实验研究。从实验中研究各射流参数对液膜外形的影响规律，继而开展理论建模，获取液膜外形的关键几何参数表达式。实验研究发现随着射流倾角增大，液膜长度减小而宽度增大，随着射流孔径和射流速度增大液膜长度和宽度均增大这一定性规律。理论分析得到了液膜最大宽度位置与液膜对称面的夹角近似等于射流倾角α，液膜的长宽比近似等于1+cot α。通过进一步分析得到液膜宽度、最大宽度距撞击点的距离、液膜长度这几个液膜关键参数的表达式。建立的液膜几何参数表达式预测结果与实验结果的误差均在20%以内。