DO 28飞行试验数据一致性检验

 本文研究DO28试验机飞行试验数据一致性检验及其误差校正。建立了由非线性运动学方程及内容广泛的校正环节构成的一致性检验模型,解决了大地风场重构、测量信号时间延迟估计、ψ转换及测量控制信号的校正。为DO28参数估计提供了可靠、准确的飞行试验数据。     

K8V变稳飞机飞行试验验证系统

介绍了Ｋ８Ｖ变稳飞机飞行试验验证系统的组成及功能,分别阐述了该系统的飞控软件综合验证子系统、机上地面试验数据采集与处理子系统和飞行试验数据处理分析子系统等三部分的组成、工作原理、以及在飞行试验各个阶段的不同特点和作用。通过Ｋ８Ｖ变稳飞机飞行试验的应用,表明该系统能够满足变稳飞机的软件维护、系统验收试飞及后续的应用研究,具有实时,快速,准确,自动化等优点,可为Ｋ８Ｖ变稳飞机应用研究提供重要的支持手段     

Data communications concept for a SATS scenario

The small aircraft transportation system (SATS) concept envisions doorstop to destination transportation in a safe and timely manner. Data communications are a key component in achieving the aviation-related operational performance improvements that are sought. However, data communication doesn't start when you get into the aircraft; it starts back at the location where the flight is planned. In fact, data communications support the pilot in all phases of the flight: flight planning, pre-flight, departure, en route, transition, approach, landing, and rollout as well as for a missed approach. The Internet is being used to perform flight planning activities, and the mobile communications available today support Internet access en route to the departure airfield. On-board the aircraft, data communications provide surveillance and air traffic control (ATC) support to the pilot. The location of other aircraft is available to the pilot and ATC system through automatic dependent surveillance-broadcast (ADS-B) and traffic information service-broadcast (TIS-B) applications that transmit the location of other aircraft in the vicinity. Other aircraft locations are used to forecast potential conflicts and, thus, enhance flight safety. As the aircraft nears a SATS-equipped airfield, the pilot uses data link messages to request a landing sequence. The airport management module (AMM) provides a landing sequence assignment to the aircraft. As the pilot maneuvers the aircraft for a landing, he/she is using data-linked surveillance data to determine the location of other aircraft and maintain a safe separation distance between aircraft even in a low visibility environment.     

电动飞机气动焦点辨识及飞行试验研究

电动飞机作为未来绿色航空的发展方向,引起了各国的广泛关注。电动飞机大多采用大展弦比气动布局,在飞行中机翼弹性变形较大,风洞试验测试的焦点结果不能较好地反映实际飞行要求。为了确定轻型电动飞机的重心范围以及得到飞行中准确的焦点位置,以某型碳纤维复合材料电动飞机为例,建立定常直线平飞和定常盘旋机动飞行的数学模型;基于盘旋机动飞行试验获得测试数据,采用物理解算法辨识得到实际飞行的焦点,并与风洞试验测得的焦点位置进行对比。结果表明：盘旋机动飞行试验辨识的飞机焦点位置要比风洞试验的结果靠前;对于展弦比较大且采用大量复合材料的电动飞机而言,在飞行过程中实际焦点位置与风洞试验结果有一定的差距,采用物理解算法辨识得到的焦点位置更接近于实际状态。     

某型电动飞机起飞加速特性分析与仿真模型修正

电动飞机从加速滑跑到飞行至安全高度是一个十分复杂的过程,在计算电动飞机起飞性能时发现用近似匀加速仿真模型得到的起飞距离小于实际的起飞距离。为了准确计算电动飞机起飞性能,在 MATLAB 中建立完整起飞过程的仿真模型并分析模型与实际起飞过程的误差,通过分析电动飞机起飞过程中加速度与速度的变化规律,引入修正函数对仿真模型中的速度进行修正;以某型电动飞机起飞性能计算为例,使用修正前后的模型对起飞过程进行仿真计算,并将计算结果与飞行试验数据进行对比。结果表明：修正后的模型精度优于修正前仿真模型的精度,修正后模型的仿真结果与飞机试飞试验结果基本一致。     

航空发动机飞行载荷谱的预测

提出了基于飞机的设计飞行任务剖面、飞行力学及发动机原理的发动机飞行载荷的预测方法,即首先将飞机的设计飞行任务剖面通过飞行力学的基本原理转化为发动机的推力（或油门）剖面,然后通过发动机性能计算获得发动机的其它工作状态参数,从而获得发动机的飞行载荷谱。      

舰载运输类飞机副翼飞行载荷设计

舰载运输类飞机布局紧凑，副翼兼备增加升力（襟副翼）、提供滚转力矩等作用。根据CCAR-25增升装置和滚转情况的设计准则，并考虑机舰适配性要求，研究了某舰载运输类螺旋桨飞机的襟副翼和副翼飞行载荷设计方法。通过机动仿真获得襟副翼、副翼典型载荷情况，通过面元法获得不同动力影响下的气动特性数据和压力分布数据，结合理论方法与工程需要，计算、筛选出襟副翼和副翼的载荷边界作为其设计载荷。研究结果表明，算例飞机的襟副翼和副翼飞行载荷受滑流影响较小；襟副翼在各个设计空速的迎面突风情况下获得设计载荷；副翼在设计俯冲速度的最大可用偏度情况下获得设计载荷。     

新舟飞机发动机防误操作设计与研究

防误操作设计作为飞机发动机操纵系统设计的一个重要组成部分,主要是防止用于反推力和低于飞行状态的桨距调定的每一操纵器件被误动而导致不安全事件的发生。通过对比分析国内外飞机防误操作的设计特点,以及新舟飞机防误操作设计上存在的不足及使用过程中暴露出来的问题,结合新舟飞机外场运营飞行数据,提出了采用轮速与空地信号同时控制飞行慢车电磁限动的控制方式,以及采用具有明显可见动作的飞行慢车机械限动方式,提高了系统的工作可靠性。     

符合适航认证要求的燃油温度计算方法

基于适航认证需要,以某型飞机中央翼油箱隔舱在规定工况下实测的燃油温度变化曲线为输入条件,借助于MATLAB多项式分段拟合功能,获取了各个阶段燃油温度变化规律的高阶函数表达式;采用Monte Carlo评估模型中规定的指数衰减方程来表征燃油温度变化规律,其中环境总温(TAT)由评估模型中所指定方法获取,平衡温差和时间常数...     

突风对着陆飞机下滑飞行的安全性影响

突风会引起飞机过载和飞行状态的改变,威胁飞机飞行安全。在飞机六自由度运动学方程的基础上,根据下滑飞行中驾驶员操纵行为的特点建立了飞机驾驶员的数学模型,并考虑突风的影响,建立了“驾驶员-飞机-突风”闭环飞机的数学仿真模型。通过引入飞机飞行安全性的量化评估理论以及表征方法,并根据飞机的飞行状态对飞机的安全性进行量化分析。选取某型飞机着陆下滑过程中进入突风风场的飞行状态进行仿真研究,结果表明风会改变飞机的气动角和空速,导致飞机的过载及飞行轨迹发生变化,尤其在飞机飞行高度较低时,风扰引起的大 但目前的研究主要集中在以阵风减缓设计为目的的 迎角姿态和飞机飞行轨迹变化将威胁飞机的飞行安全。     

Aircraft emission research within ISTC project

This research is aimed at obtaining experimental data on contamination of the atmosphere by emissions from aircraft engines in cruise flight conditions, to establish and improve models of the physical and chemical processes which take place in the aircraft wake and in the general zone of air traffic corridors. An Su-24 ‘sounder’ aircraft equipped with an air sampling and collection system has been established to obtain the necessary atmospheric samples in flight, and procedures have been developed for performing the research flights. Techniques have also been developed for chemical analysis of the samples.     

舵面破损对飞机轴间运动耦合飞行品质的影响

为研究舵面破损对电传控制飞机轴间运动耦合飞行品质的影响,选取了能够反映飞机多轴运动耦合特性的飞行品质评定任务,建立了舵面破损飞机的飞行动力学模型,选取了适用于表征飞机轴间运动耦合程度的特征参数,形成了基于任务的角速率指令式电传控制飞机轴间运动耦合飞行品质的评定方法。采用该方法对具有不同舵面破损程度的算例飞机开展了飞行品质评估试验,得到了能够量化舵面破损对角速率指令式电传控制飞机飞行品质影响的特征参数取值规律。研究结果对于舵面破损情形下飞机飞行安全与作战效能评估等均有一定的理论参考价值。     

Water takeoff performance calculation method for amphibious aircraft based on digital virtual flight

Owing to the strong coupling among the hydrodynamic forces, aerodynamic forces and motion of amphibious aircraft during the water takeoff process, the water takeoff performance is difficult to calculate accurately and quickly. Based on an analysis of the dynamics and kinematics characteristics of amphibious aircraft and the hydrodynamic theory of high-speed planing hulls, a suitable mathematical model is established for calculating the hydrodynamics of aircraft during water takeoff. A pilot model is designed to illustrate how pilots are affected by the lack of visual reference and the necessity to simultaneously control the pitch angle, flight velocity and other parameters during water takeoff. Combined with the aerodynamic model, engine thrust model and aircraft motion model, a digital virtual flight simulation model is developed for amphibious aircraft during water takeoff, and a calculation method for the water takeoff performance of amphibious aircraft is proposed based on digital virtual flight. Typical performance indicators, such as the liftoff time and liftoff distance, can be obtained via digital virtual flight calculations. A comparison of the measured flight test data and the calculation results shows that the calculation error is less than 10%, which verifies the correctness and accuracy of the proposed method. This method can be used for the preliminary evaluation of airworthiness compliance of amphibious aircraft design schemes, and the relevant calculation results can also provide a theoretical reference for the formulation of flight test plans for airworthiness certification.     

鸭式旋翼/机翼飞机悬停状态飞行动力学特性

针对鸭式旋翼/机翼(Canard Rotor/Wing,CRW)飞机独特的气动布局,常规的分析方法及经验公式很难准确地对CRW飞机进行飞行动力学研究,通过飞行辨识对CRW飞机悬停状态特性进行了研究。首先,设计了飞行试验并获得了高质量的飞行数据,基于频率响应对CRW飞机的状态空间模型进行了简化。然后,在频域内对飞机的动力学参数进行了拟合优化,获得了CRW飞机悬停状态的动力学模型,并用飞行数据对所建模型进行了验证。最后,用辨识所得参数与常规直升机悬停状态时的参数进行了对比。结果显示悬停时CRW飞机的操纵导数和阻尼导数均比常规直升机小,经分析,操纵导数的减小主要是CRW飞机独特的旋翼设计所致,阻尼导数减小的原因主要是旋翼气动影响以及鸭翼、平尾、垂尾的结构影响。动力学特性分析结果为CRW飞机旋翼模式总体设计的进一步优化提供了指引和参考,所建立的模型可用于控制系统设计。     

飞机带动力模型试验前准备与校准研究

带有高涵道比发动机的民用飞机无论是在高速还是低速飞行时,发动机进、排气对气动特性的影响都不可忽视,尤其是在低速增升构型时进排气的影响更为重要。为了研究发动机动力影响对飞机气动特性的影响,在一个飞机半模模型的发房内安装了TPS发动机模拟器,通过构型变化和运行参数调节来获得低速状态下带动力的影响量。为了获取可靠的数据,试验前需要对TPS进行必要的调试与校准,本文对这些内容进行了详细的阐述。     

Intelligent modeling and identification of aircraft nonlinear flight

In this paper, a new approach has been proposed to identify and model the dynamics of a highly maneuverable fighter aircraft through artificial neural networks（ANNs）. In general, aircraft flight dynamics is considered as a nonlinear and coupled system whose modeling through ANNs, unlike classical approaches, does not require any aerodynamic or propulsion information and a few flight test data seem sufficient. In this study, for identification and modeling of the aircraft dynamics, two known structures of internal and external recurrent neural networks（RNNs） and a proposed structure called hybrid combined recurrent neural network have been used and compared.In order to improve the training process, an appropriate evolutionary method has been applied to simultaneously train and optimize the parameters of ANNs. In this research, it has been shown that six ANNs each with three inputs and one output, trained by flight test data, can model the dynamic behavior of the highly maneuverable aircraft with acceptable accuracy and without any priori knowledge about the system.     

Multipoint optimization on fuel efficiency in conceptual design of wide-body aircraft

Aircraft conceptual design optimizations that maximize the performance at a design condition (single-point) may result in designs with unsatisfying off-design performance. To further improve aircraft efficiency under actual flight operations, there is a need to consider multiple flight conditions (multipoint) in aircraft conceptual design and optimization. A new strategy for multipoint optimizations in aircraft conceptual design is proposed in this paper. A wide-body aircraft is taken as an example for both single-point and multipoint optimizations with the objective of maximizing the specific hourly productivity. Boeing 787-8 flight data was used in the multipoint optimization to reflect the true objective function. The results show that the optimal design from the multipoint optimization has a 7.72% total specific hourly productivity increase of entire flight missions compared with that of the baseline aircraft, while the increase in the total specific hourly productivity from the single-point optimal design is only 5.73%. The differences between the results of single-point and multipoint optimizations indicate that there is a good option to further improve aircraft efficiency by considering actual flight conditions in aircraft conceptual design and optimization.     

风切变对飞机平飞特性的影响分析

利用对风切变的描述,建立微下冲气流工程化模型。随后根据建立起的风切变运动方程,对飞机穿越微下冲气流风场进行仿真,分析了风切变对飞机飞行性能的影响。     

飞机飞行载荷测量载荷方程的优选

介绍用应变计方法测量飞机飞行载荷的载荷方程,应用方差分析和下检验技术进行优选,逐次剔除无应电桥和多余电桥,经自动计算,得到仅会对某种载荷有显著贡献的少量电桥的最优载荷方程,供飞行试验测量飞机飞行载荷使用。算例结果表明,此方法获得最优载荷方程有效。     

民机防冰系统自然结冰试飞技术研究

结合某型民机自然结冰条件下防冰系统的试飞,对试飞所需的测试改装工作进行了总结,并对试飞前需进行的各种安全性评估进行了总结说明,明确了试飞中需考虑的各种构型情况,提出一套循序渐进的自然结冰试飞方法。同时提出了试飞中结冰气象参数的可接受性判据,最后针对自然结冰试飞中结冰气象参数的处理提出了分段等效处理的方法。