An innovative approach for integrated airline network and aircraft family optimization

The determination of optimal aerial transport networks and their associated flight frequencies is crucial for the strategic planning of airlines, as well as for carrying out market research, to establish target markets, and for aircraft and crew rostering. In addition, optimum airplane types for the selected networks are crucial to improve revenue and to provide reduced operating costs. The present study proposes an innovative approach to determine the optimal aerial transport network simultaneously with the determination of the optimum fleet for that network, composed of three types of airplanes (network and vehicle integrated design). The network profit is maximized. The passenger’s demands between the airports are determined via a gravitational model. An embedded linear programming solution is responsible for obtaining potential optimal network configurations. The optimum fleet combination is determined from a database of candidate aircraft designs via genetic algorithm. A truly realistic airplane representation is made possible thanks to accurate surrogate models for engine and aerodynamics is adopted. An accurate engine deck encompassing a compression map and an innovative engine weight calculation besides an aerodynamical artificial neural network module enable a high degree of accuracy for the mission analysis. The proposed methodology is applied to obtain the optimum network comprised of twenty main Brazilian airports and corresponding fleet.     

K8、JK8机翼接头与检验量规协调准确度的提高

分析了 K8、 JL8机翼接头孔精加加后与检验量规位置协调的条件，介绍了为提高它们之间协调准确度所采取的措施及其效果。     

J—7LP飞机1：6遥控模型失速尾旋试验

对无动力J—7LP动力学缩比模型进行了遥控试飞,以研究其失速尾旋特性,全偏平尾和方向舵可使模型进八尾旋,舵面全回中即可从各种尾旋中改出。偏转副翼对尾旋特性有明显的影响。     

Digital Aircraft Sheet Metal Part Manufacturing System and Its Key Technology

The architecture of digital sheet metal manufacturing system is proposed based on the classification of sheet metal manufacturing information.The essence of digital manufacturing is the definition,management and transfer of information,and the key technologies are brought forward and described.It is pointed out that knowledge-based manufacturing elements design is necessary to make digital technology efficient.The management of all kinds of sheet metal manufacturing element information is to build single source of manufacturing data.Multi-state model-based digital transfer and coordination method is designed to provide a foundation for digital manufacturing of aircraft sheet metal part.The application of digital sheet metal manufacturing is exemplified with an aircraft sheet metal part.The application result is compared to that of the traditional analog transfer technology.It is shown that the developed technology can improve part quality,shorten manufacturing time and lower manufacturing cost.     

求解装箱问题的遗传算法

本文提出了两种求解装箱问题（ＢｉｎＰａｃｋｉｎｇ）的遗传算法。一种是简单遗传算法,它采用等长度字符代码编码方法,使用常规的遗传操作算子。另一种是混合遗传算法,它综合运用解装箱问题的ＦＦＤ（ＦｉｒｓｔＦｉｔＤｅ－ｃｒｅａｓｉｎｇ）近似算法和简单遗传算法。试算结果表明,由这两种遗传算法所得到的装箱方案较一些近似算法所得到的装箱方案都要好。     

航空发动机全程滑态变结构控制研究

一种新的滑模变结构控制方法-全程滑态变结构控制首次应用于航空发动机控制系统，该控制方法能有效地缩短系统状态到达滑动模态的时间，避免了定常滑态变结构控制系统在能达阶段对扰动的敏感性，且其控制律的设计可以改善系统的瞬态性能，克服未知参数摄动的影响，仿真结果表明，基于全程滑态变结构控制所设计的发动机控制系统，其鲁棒性要优于发动机定常滑态结构控制系统。     

航空发动机进口温度畸变参数和防喘控制系统设计

主要研究了航空发动机防喘控制系统的设计和研制，特别是研究了当战斗机发射导弹时温度畸变对发动机的影响。引入的温度畸变参数包括：进口相对平均温升δT；进口温升率dT／dt；当量热区角Φe；连续温度畸变时间tB。通过试验和数据分析的方法得出发动机防喘控制系统的设计准则，发动机防喘控制系统的研制和飞行试验证明了该设计准则的正确性。     

凹槽火焰稳定器结构对煤油超声速燃烧的影响

采用混合分数平衡化学反应模型和离散液滴模型，研究了不同长深比和后缘倾角的凹槽在液体煤油双模态燃烧中的火焰稳定特性。结果表明，集燃料喷射、混合及火焰稳定为一体的凹槽，在所模拟的工作过程中增强了燃料与空气的混合和燃烧；并得到最优的凹槽结构；混合分数平衡化学反应模型和离散液滴模型能准确地预测煤油在双模态燃烧室内的喷雾燃烧。     

Instability and unsteadiness of aircraft wake vortices

This paper presents a review of theoretical and experimental results on stability and other unsteady properties of aircraft wakes. The basic mechanisms responsible for the propagation and the amplification of perturbation along vortices, namely the Kelvin waves and the cooperative instabilities, are first detailed. These two generic unsteady mechanisms are described by considering asymptotic linear stability analysis of model flows such as vortex filaments or Lamb–Oseen vortices. Extension of the linear analysis to more representative flows, using a biglobal stability approach, is also described. Experimental results obtained using LDV, hot wire and PIV in wind tunnels are presented and they are commented upon the light of theory.     

叉排型扰流柱排内部流场的实验研究

在特别建造的小型扰流柱排风洞上，测量了6个不同雷诺数下叉排型短扰流柱排内部的流场分布，发现不同雷诺数下流场分布非常相似，在奇数和偶数测量截面上，速度分布规律不同，在奇数截面上可以观察到通道涡，在偶数截面的端壁附近存在马蹄涡。