高斯粗糙表面电磁散射的曲率修正双尺度法

在传统双尺度法分析粗糙表面电磁散射特性的基础上，通过对大尺度切平面的曲率修正。给出了小入射角时改进双尺度法的计算模型。采用传统微扰法和基于圆柱曲面修正的微扰法，计算了实际粗糙面掠入射时的后向散射系数，并与有关测量值进行了比较。结果表明，在中、小入射角及掠入射条件下，基于曲率修正双尺度法的计算结果与实际值均较为相近，证明该方法有效。     

填料吸湿对衬层界面粘接性能的影响

研究了ＦＳ，ＳｉＯ２（沉淀法），ＴｉＯ２三种填料和预固化衬层的吸湿对层界面粘接性能的影响。研究表明ＰＳ，ＳｉＯ２是易吸湿性填９料，ＴｉＯ２基本上不吸湿，衬层配方中添加易吸湿性填料会增加预固化衬层的吸湿量，降低衬层界面粘接性能。     

基于试飞数据的涡轴发动机性能建模技术

为了实现军用涡轴发动机在装机状态下的虚拟预测试飞，通过罚函数法求解超定非线性方程组的最小二乘解，并采用回归分析对部件特性耦合因子进行曲线拟合，优化基准稳态模型，构建了某型涡轴发动机稳态性能计算模型；在此基础上，应用发动机加减速试飞数据，综合考虑部件容腔效应、转动部件的转子动力学和高温部件的传热效应，开发了涡轴发动机部件级过渡态性能计算模型。采用该模型对包线范围内不同工况的发动机稳态和过渡态工作过程进行了仿真预测，结果表明：与真实装机试验结果相比，发动机各工作参数的稳态预测精度在4.2%以内，过渡态预测精度在9.2%以内，满足工程精度要求。该模型能够满足虚拟预测试飞的技术需求，对涡轴发动机的设计、试飞和使用具有重要作用。     

3238树脂及其改性

 采用芳香二胺对3238韧性中温固化环氧树脂体系进行了改性。通过芳香二胺和环氧树脂预先反应,消除了芳香二胺对中温环氧树脂的固化及工艺的影响,改性前后差示扫描量热法（DSC）初始温度和峰顶温度的差别仅有3 ℃,最终固化程度的差别也仅有1%。通过芳香二胺刚性结构的引入,由于芳香二胺和环氧树脂的交联密度高于双氰胺环氧树脂体系,因此引入芳香二胺刚性结构提高了3238树脂的耐热性,干态玻璃化转变温度提高了29 ℃,且纯固化后树脂吸湿量降低了0~34%,湿态玻璃化转变温度提高了46 ℃。改性后树脂可能形成了高低交联密度区,产生了固化物交联状态的不均匀,在提高树脂体系耐热性能的同时,保持其原有的韧性,树脂浇注体的拉伸应力应变曲线呈明显的塑性变形,拉伸断裂伸长率达5~31%,复合材料的断裂韧性达1 133 J/m²。     

利用数显装置改造型架装配机

利用目前国内外已成熟的数显技术,对9m型架装配机进行了技术改造。本文简要介绍了技术改造方案及系统调试过程。     

活塞理论气动力静压修正方法及其在曲壁板颤振分析中的应用

提出了一种采用计算流体力学(CFD)计算的压力分布对活塞理论气动力进行静压修正的方法,将该方法应用到曲壁板的静气动弹性变形及颤振稳定性分析中,并与采用曲率修正活塞理论气动力的计算结果进行了对比.分析结果表明,采用本文提出的活塞理论气动力静压修正方法进行曲壁板的气动弹性分析,在圆柱曲壁板曲率较小的情况下,与采用曲率修正活塞理论气动力方法得到的静气动弹性变形、稳定性边界差别不大;而在曲率较大时,采用本文方法计算得到的曲壁板静气动弹性变形,其曲壁板靠近前缘部分被压的更低,而曲壁板的颤振稳定性边界更小,且这种差别随着圆柱曲壁板曲率的增加而不断增大.该方法突破了曲率修正活塞理论的小曲率限制,扩大了活塞理论气动力在曲壁板颤振分析中的适用范围.     

唇口斜切修型对S形进气道RCS影响

采用基于迭代物理光学法与等效边缘电磁流法的雷达散射截面计算程序,分析了水平、垂直两种极化方式下唇口斜切修型对菱形进口S形进气道边缘绕射场及腔体内部散射场的影响。计算结果表明：在水平、垂直两种极化方式下,斜切修型可有效降低边缘绕射场的雷达散射截面,但随斜切角度的增大,其减小幅度降低;正负斜切角度对应的绕射场雷达散射截面分布关于0°探测角对称;斜切修型对腔体内部散射场的影响较小。     

The lower ionosphere response to its disturbances by powerful radio waves

The paper presents data from some campaigns at Sura heating facility in 2011–1016. The experiments on probing of the artificial disturbed region of the lower ionosphere were carried out at two observation sites. One of them was located near Vasil’sursk 1 km from Sura facility (56.1°N; 46.1°E) and the other site was located at the Observatory (55.85°N; 48.8°E) of Kazan State University, 170 km to the East. Investigation of the features of the disturbed region of the lower ionosphere based on its diagnostics by the methods of the vertical sounding and oblique backscattering is the main goal of this paper. Ionosphere disturbance was fulfilled by the effect of the powerful radio wave of the ordinary or extraordinary polarization emitted by transmitters of the Sura facility with effective radiated power ERP = 50–120 MW at the frequency of 4.3, 4.7 and 5.6 MHz. Pumping waves were emitted with period from 30 s to 15 min. The disturbed region of the ionosphere in Vasil’sursk was probed by the vertical sounding technique using the partial reflexion radar at the frequency of 2.95 and 4.7 MHz. For the oblique sounding of the disturbed region the modified ionosonde Cyclon-M, operating at ten frequencies from 2.01 to 6.51 MHz was used at the Observatory site. On many heating sessions simultaneous variations of the probing partial reflection signals in Vasil’sursk and backscattered signals in Observatory were observed at the height at 40–100 km below the reflection height of the pumping wave. These observations were correlated with the pumping periods of the Sura facility. Possible mechanisms of the appearance of the disturbance in the lower ionosphere and its effect on the probing radio waves are discussed.     

Modified robust optimal adaptive control for flight environment simulation system with heat transfer uncertainty

To solve the rapid transient control problem of Flight Environment Simulation System (FESS) of Altitude Ground Test Facilities (AGTF) with large heat transfer uncertainty and disturbance, a new adaptive control structure of modified robust optimal adaptive control is presented. The mathematic modeling of FESS is given and the influence of heat transfer is analyzed through energy view. To consider the influence of heat transfer in controller design, we introduce a matched uncertainty that represents heat transfer influence in the linearized system of FESS. Based on this linear system, we deduce the design of modified robust optimal adaptive control law in a general way. Meanwhile, the robust stability of the modified robust optimal adaptive control law is proved through using Lyapunov stability theory. Then, a typical aero-engine test condition with Mach Dash and Zoom-Climb is used to verify the effectiveness of the devised adaptive controller. The simulation results show that the designed controller has servo tracking and disturbance rejection performance under heat transfer uncertainty and disturbance; the relative steady-state and dynamic errors of pressure and temperature are both smaller than 1% and 0.2% respectively. Furthermore, the influence of the modification parameter γ is analyzed through simulation. Finally, comparing with the standard ideal model reference adaptive controller, the modified robust optimal adaptive controller obviously provides better control performance than the ideal model reference adaptive controller does.     

整体叶盘电解加工阴极修正方法与试验

电解加工是航空发动机整体叶盘制造的主要技术之一,阴极修正是该加工技术的重要环节。为了提升阴极修正精度,提出了恒采样点空间法向修正方法。该方法将阴极型面设计、加工误差分析、工具阴极修正统一至阳极采样点空间法向的一维坐标系中,将复杂的三维曲面修正简化为离散的一维修正,消除了加工误差与修正量的错位。以某整体叶盘为例,在自行研制的整体叶盘型面电解加工机床上开展工具阴极修正试验,采用三坐标测量机对修正前后的加工样件进行检测,经过一次修正,叶片电解加工精度由0.25mm提高至0.04mm,试验结果表明该阴极修正方法合理有效,具有较强的可行性。