J7L飞机大迎角/失速/尾旋试飞

介绍了J7L飞机大迎角／失速／尾旋试飞的目的，简要说明了大迎角／尾旋试飞前的预先研究工作，并结合具体的试飞结果曲线对J7L飞机失速／尾旋特性及改出方法进行了分析。结果表明，该方法可用于常规布局飞机的大迎角／失速／尾旋试飞，为新机试飞提供了有效的参考依据。     

现代机动飞机的失速／尾旋试飞方法

评定飞机的大迎角特性失速试验和尾旋试验，失速试验的目的是确定最大可用升力边界；而尾旋试验的目的是确定飞机超出正常迎角范围时的动力特性并为飞行员建立一套适用的尾旋改出方法。失速试验一般是按预先规定的速度减小速率或过载量级逐渐趋于失速，但处于安全考虑，在未达到气分离时便停止试验，之后，对飞机进行专门改装，经过指定数目的旋进行有意尾旋，从而确定尾旋改出技术，这种常规失速／尾旋试飞方法，无法准确地描述飞机     

现代飞机失速／过失速／尾旋飞行试验技术

概要介绍了现代飞机失速／尾旋研究的途径，失速／过失速／尾旋试飞验证的目的，试验方法和测试要求，较详细地介绍了现代飞机失速／过失速／尾旋试飞验证的程序和步骤，对装有迎角限制器飞机特殊要求，应急改出尾旋装置的安装使用以及与安全有关的一些注意事项。     

某型教练飞机尾旋特性试飞研究

为了解决某型教练机大迎角/失速/尾旋设计定型的技术难题,依据GJB3814《军用飞机失速/过失速/尾旋试飞验证要求》,开展了尾旋试飞技术研究,提出了符合军标验证要求的尾旋特性试飞方法,包括不同进入方法、不同改出方法、最佳改出方法以及改出过程中误操纵等。通过试飞发现：该飞机对偏离是敏感的,但对尾旋等过失速模态是阻抗的;该飞机存在＂过失速旋转＂、＂落叶飘＂、＂振荡正飞陡尾旋＂以及＂倒飞尾旋＂四种典型的过失速模态;＂三中立＂法可以较迅速改出发现的四种过失速模态,与失速改出方法具有同一性且不需要过多驾驶技巧,为试飞员推荐的最佳改出动作。     

M_ИΓ──21型飞机失速／尾旋飞行试验

在系统地进行ＴИΓ—２１型飞机失速／尾旋理论培训和试验飞行的基础上，结合实际飞行中的机载测试记录和体会，详细介绍了失速／尾族试飞的准备、试飞驾驶技术和失速尾旋特性。给出了ＭИΓ－２１型飞机典型的正常尾旋和倒飞尾旋的试飞结果曲线。最后针对ＭИΓ－２１型飞机的特点，给出了失速／尾旋试飞中特别的限制说明。供同类型飞机失速／尾旋试飞时参考。     

F—16飞机大迎角飞行特性分析

采用六自由度全量运动方程和三通道飞行控制系统模型，使用时域动态响应的方法，研究了Ｆ－１６飞机在大迎角下飞行的深失速特性和尾旋特性，并对尾旋进入和改出的机理进行了探讨。通过分析研究可午出结论：Ｆ－１６飞机具有深失速特性，若进入深失速后，可用先拉杆后推杜操纵方法改出；Ｆ－１６飞机进入尾旋的主要原因是航向自转和偏航、滚转气动交感；在改出尾旋过程中，方向舵操纵力矩、航向静不稳定力矩、偏航惯性交感力矩对制止     

失速尾旋试飞动力装置可靠性分析

失速尾旋试飞是高难度、极危险的特技飞行科目,飞机动力装置的工作特性和可靠程度显得非常重要。本文通过对动力装置可靠性分析,对飞机失速尾旋飞行试验提供了可靠性结论。     

反尾旋伞动态仿真计算研究

简要介绍了研制与安装应急反尾旋伞系统对现代高机动飞机的大迎角特性试验研究的重要作用，特别是对失速／过失速／尾旋特性试验鉴定的必要性和重要性。介绍了反尾旋伞系统的工作原理，建立了反尾旋伞的数学模型，估算确定了反尾旋伞阻力面积，并对用反尾旋伞出尾旋进行了动态仿真计算；同时，研究了不同尺寸反尾旋伞的尾旋改出效果。     

МИГ——21型飞机失速／尾旋飞行试验

在系统地进行了ＭИГ－－２１型飞机失速／尾旋理论培训和试验飞行的基础上，结合实际飞行中的机载测试记录和体会，详细介绍了失速／尾旋试飞的准备、试飞驾驶技术和失速尾旋特性。     

飞机失速/尾旋特性的预测和试验研究

以一架三角翼战斗机为例,详细地介绍了利用风洞大迎角静、动态试验数据及旋转开平试验数据,开展收音机大迎角全局稳定性分析、六自由度计算及地面飞行模拟试验等预先研究。利用投放模型进行了自由飞快行旋试验以及最终完成的全尺寸飞机的失速／过失速／尾旋验证试飞,对预测结果与试验结果进行了相关分析,结果表明两者有较好的一致性。     

ν-gap度量及其在飞行控制律评估中的应用

 传统控制律评估方法主要用于单输入单输出（SISO）系统，且对模型参数摄动考虑不够全面,针对这些不足，研究了ν-gap度量方法。在介绍系统广义稳定裕度相关概念的基础上，给出了ν-gap度量的定义、特点和性质以及近似摄动模型的计算，提出ν-gap度量评估控制律的步骤。实例结果表明，该方法不仅克服了上述传统评估方法的缺陷，而且还有根据所求的各摄动影响情况忽略影响小的元素，以减少计算量及可以找到最坏情况下的参数摄动组合等优点。     

Integrated Entry Guidance for Reusable Launch Vehicle

A method for the implementation of integrated three-degree-of-freedom constrained entry guidance for reusable launch vehicle is presented. Given any feasible entry conditions, terminal area energy management interface conditions, and the reference trajectory generated onboard then, the method can generate a longitudinal guidance profile rapidly, featuring linear quadratic regular method and a proportional-integral-derivative tracking law with time-varying gains, which satisfies all the entry corridor constraints and meets the requirements with high precision. Afterwards, by utilizing special features of crossrange parameter, establishing bank-reversal corridor, and determining bank-reversals according to dynamically adjusted method, the algorithm enables the lateral entry guidance system to fly a wide range of missions and provides reliable and good performance in the presence of significant aerodynamic modeling uncertainty. Fast trajectory guidance profiles and simulations with a reusable launch vehicle model for various missions and aerodynamic uncertain-ties are presented to demonstrate the capacity and reliability of this method.     

基于飞机油箱模型形状特征油量测量切片步长选择方法研究

 在分析飞机数字式油量测量过程中目前广泛使用的切片法油量测量原理的基础上,针对现有的定步长切片法无法得到准确、可靠的燃油质量特性数据库的缺陷,结合对飞机油箱模型形状特征的分析,提出了基于飞机油箱模型形状特征的油量测量切片步长选择方法。此方法包括切片步长整体和局部选择两个过程,整体选择以实现相邻两切片平面所夹油箱模型体积近似相等为目的来确定切片步长,以体现油箱模型截面整体变化规律;局部选择以设计切片平面与截面突变平面重合或尽可能接近的方式,突出油箱截面的局部变化特征。实验结果表明：该切片步长选择方法较定步长方法能够建立更为合理、可靠的燃油质量特性数据库,从而提高了油量测量精度。     

The effect of inlet conditions on the flow and heat transfer in multiple rotating cavity with axial throughflow

This paper discusses experimental results from two different build configurations of a heated multiple rotating cavity test rig.Measurements of heat transfer from the discs and tangential velocities are presented.The test rig is a 70% full scale version of a high pressure compressor stack of an axial gas turbine engine.Of particular interest are the internal cylindrical cavities formed by adjacent discs and the interaction of these with a central axial throughflow of cooling air.Tests were carried out for a range of non-dimensional parameters representative of high pressure compressor internal air system flows(Re up to 5×106 and Rez up to 2×105).Two different builds have been tested.The most significant difference between these two build configurations is the size of the annular gap between the(non-rotating) drive shaft and the bores of the discs.The heat transfer data were obtained from thermocouple measurements of surface temperature and a conduction solution method.The velocity measurements were made using a two component,LDA system.The heat transfer results from the discs show differences between the two builds.This is attributed to the wider annular gap allowing more of the throughflow to penetrate into the cavity.There are also significant differences between the radial distributions of tangential velocity in the two builds of the test rig.For the narrow annular gap,there is an increase of non-dimensional tangential velocity V/Ωr with radial location to solid body rotation V/Ωr=1.For the wider annular gap,the non-dimensional velocities show a decrease with radial location to solid body rotation.      

二维翼段颤振的μ控制

 采用超声电机作为作动器来实现含控制面的翼段颤振鲁棒抑制。针对作者设计的二维翼段颤振主动抑制系统，通过理论与实验相结合的方法，建立了考虑沉浮方向阻尼和作动器模型参数不确定性的控制系统模型，设计了μ控制器，并对控制器做了降阶处理。数值仿真和风洞试验表明，μ控制器可有效地抑制颤振的发生，将颤振临界速度提高23.4%。相对于H_∞控制器，μ控制器的控制效果和鲁棒性更好。     

航空发动机管路测量数据分割方法

 为了提高航空发动机管路测量数据的反求建模效率,提出了一种区域增长分割算法。该方法主要是利用管路表面在曲面索引系数映射、主曲率映射、高斯映射上的特性,并基于均值漂移算法和遗传算法提出了区域分割算法中种子区域的选择策略。然后利用区域增长分割方法实现了对管路测量数据的分割。经过仿真和实测数据验证,所提管路分割算法具有较好的分割质量和效率。     

Abnormal Shape Mould Winding

为解决网格化芯模的缠绕问题,本文提出了复合材料面片缠绕机理;接着详细分析了面片缠绕过程中的芯模凹曲面上纤维滑线和架空现象,应用微分几何曲面理论和空间几何理论,提出判据及其解决方案;最后,针对飞机发动机进气道的缠绕成型,编制缠绕控制程序并进行相应的实验,验证了面片缠绕方法的可行性。     

Interfacial Properties Modification of Carbon Fiber/ Polyarylacetylene Composites

This work was dedicated to performing surface oxidation and coating treatments on carbon fibers (CF) and investigating the changes of fiber surface properties after these treatments, including surface composition, relative volume of functional groups, and sur- face topography with X-ray photoelectron spectroscopy (XPS) and atom force microscopy (AFM) technology. The results show that, after oxidation treatments, interfacial properties between CF and non-polar polyarylacetylene (PAA) resin are remarkably modified by removing weak surface layers and increasing fiber surface roughness. Coating treatment by high char phenolic resin solution after oxida- tion makes interface of CF/PAA composites to be upgraded and the interfacial properties further bettered.     

Thermal Stresses and Cracks During the Growth of Large-sized Sapphire with SAPMAC Method

本文利用有限元法对冷心放肩微量提拉法(SAPMAC)生长大尺寸蓝宝石单晶过程中的热应力进行了模拟计算,应用临界缺陷理论解释了裂纹的萌生与扩展机理。研究表明,晶体内的热应力主要与晶体生长速率,环境温度和结晶取向有关;较大热应力多出现在结晶界面,放肩、收尾以及直径急剧变化等位置;最大热应力总是出现在籽晶与新生晶体的界面附近。裂纹将在临界缺陷位置产生,并在应力作用下沿a或m面扩展。计算结果与实验结果基本吻合,通过晶体生长系统和生长工艺的改进,对晶体的开裂问题得到了有效的抑制。     

Optimization Design System for Composite Structures Based on Grid Technology

To solve the topology optimization of complicated multi-objective continuous/discrete design variables in aircmit structure design, a Parallel Pareto Genetic Algorithm （PPGA） is presented based on grid platform in this paper. In the algorithm, the commercial finite element analysis （FEA） software is integrated as the calculating tool for analyzing the objective functions and the filter of Pareto solution set based on weight information is introduced to deal with the relationships among all objectives. Grid technology is utilized in PPGA to realize the distributed computations and the user interface is developed to realize the job submission and job management locally/remotely. Taking the aero-elastic tailoring of a composite wing for optimization as an example, a set of Pareto solutions are obtained for the decision-maker. The numerical results show that the aileron reversal problem can be solved by adding the limited skin weight in this system. The algorithm can be used to solve complicated topology optimization for composite structures in engineering and the computation efficiency can be improved greatly by using the grid platform that aggregates numerous idle resources.