基于响应面近似技术的平流层飞艇协同设计优化

针对平流层飞艇多学科设计优化问题,引入协同优化算法,分析基于响应面近似模型的协同优化方法CO/RSA的执行步骤和特点,并介绍响应面近似模型的构建方法;建立平流层飞艇各学科模型,并对学科间耦合关系进行分析;运用建立的气动/推进、结构、能源三个耦合子系统的学科分析模型和系统优化模型,以平流层飞艇总质量最小为优化目标,综合考虑浮重、推阻和能源平衡,采用CO/RSA方法对平流层飞艇进行设计优化.结果表明:所建立的平流层飞艇的MDO模型是合理的,CO/RSA算法应用于飞艇总体设计优化是有效的,研究结果可为平流层飞艇方案论证和方案设计提供参考.     

Effect of sodium tartrate concentrations on morphology and characteristics of anodic oxide film on titanium alloy Ti–10V–2Fe–3Al

The effect of sodium tartrate concentrations on morphology and characteristics of ano-dic oxide film on titanium alloy was investigated. The alloy substrates were anodized in different concentration solutions of sodium tartrate with the addition of PTFE emulsion and their morphol-ogy and characteristics were analyzed. The anodic oxide film presented a uniform petaloid drums and micro-cracks morphology. Additionally, micro-cracks dramatically swelled with the increase of the tartrate concentrations. The thickness of the anodic oxide film increased with the concentra-tions until the concentration reached 15 g/L. The results of Raman analysis illustrate that all sam-ples have similarity in the crystal structure, consisting of mainly amorphous TiO2, some anatase TiO2 and a small amount of rutile TiO2. And the ratios of anatase TiO2 and rutile TiO2 increase with the concentrations until it reaches 15 g/L. Furthermore, the intensity of the peaks increases with enhanced concentrations until the concentration reaches 15 g/L. The corrosion resistance of the anodic oxide film is increased by the sodium tartrate with higher concentrations before 15 g/L. The coefficient of friction of the anodic oxide film reduces with the concentrations until the concentration reaches 15 g/L, then the coefficient of friction of the anodic oxide film increases with the concentrations.     

中介机匣典型故障排除及深度修理

航空发动机中介机匣组件因各种故障而需修理或导致报废的现象时有发生。针对发动机中介机匣分流环裂纹掉块、上部衬套磨损松动、弹性环磨损、同心度检测不合格等故障进行分析研究,提出解决措施,制定满足发动机使用要求的合理技术标准和修理方法。在修理技术方法中,采用挖补补焊方法解决分流环裂纹掉块故障;采用极坐标定位与专用模板衬套相结合的方法提高新品衬套加工精度以解决上部衬套更换新品后装配准确性难题;采用装配过盈销钉和扩口工艺以保证零件的堵孔质量等。结果表明:这些修理措施提高了中介机匣零部件的利用率,延长了其使用寿命,降低了发动机修理成本。     

柔性热膜剪应力传感器水下测量温度修正

柔性热膜微传感器应用于流体壁面剪应力测量时,流体温度对传感器输出有很大影响,因此有必要对工作在非标定温度下的传感器输出信号进行修正补偿。重点研究了水下测量时传感器输出与水温的关系以及温度修正方法。通过分析传感器过热比和流体物理性质与温度的相关性,建立了流体温度与传感器过热比和标定系数的函数关系。在此基础上,提出了一种用于水下剪应力测量的温度修正方法,可以有效减小水温对传感器输出的影响。经实验验证,该方法可以使工作在25℃、28℃水温环境下的传感器输出值与其20℃标定值的相对误差从23．7％和37．1％回落到0．82％和0．83％。     

基于TARAM的民用飞机结构类事件的持续运营安全评估

在民用飞机持续适航阶段,需要开展风险评估工作,以保证运营安全水平能够维持在可接受的范围之内。基于运输类飞机风险评估方法（TARAM）及风险准则,考虑不同的结构裂纹尺寸,给出基于机队故障数、临界裂纹、特征寿命的机队风险值计算方法;以机身增压边界结构受到循环增压载荷的疲劳裂纹为例,进行持续安全风险评估,计算该事件的风险水平,以及纠正措施实施时限;并通过使用纠正措施实施时限内个人风险进行验证。结果表明：个人风险低于风险阈值,本文制定的纠正措施及实施时限满足机队持续安全要求,可保证该机队的运行安全。     

航空锂电池适航审定规章解读及符合性方法研究

锂离子电池作为动力电池有着优异的性能,在民航行业上有广阔的应用前景。但行业对其技术特征 和安全风险的认识还不充分,现行的规章条款缺乏足够的安全要求,国外局方针对锂离子电池颁发了专用条 件,但回顾相关事故可以发现,锂离子电池的验证和审查环节还不完善,相关条款更新修正的步伐也同锂电池 的发展现状和技术水平不相适应。以航空锂电池事故为例,分析航空锂离子电池作为动力电池的安全性风险, 从对现有规章条款和专用条件的解读出发,借鉴不同行业近年来积累的锂电池验证和使用经验,针对航空动力 锂电池的适航符合性方法提出一些改进方案,可作为现有锂电池适航符合性方法的有益补充,为自主建立健全 适航验证规范体系做出探索。     

公转速度对冷滚打成形制件回弹影响研究

在冷滚打成形过程中,滚打轮对工件击打和滚压的同时,工件变形区域储存了较大的弹性应变能,导致工件成形结束后会出现回弹,回弹现象对成形工件的廓形精度有着较大的影响。本文主要针对滚打轮公转速度与回弹量之间的关系进行研究。建立了冷滚打成形回弹的有限元仿真模型,通过动态仿真分析获得了不同公转速度时成形齿槽截面在切向、轴向和径向的变形规律;通过静态分析获得了成形齿槽截面各部分在不同公转速度下切向、轴向和径向的回弹规律。结果表明,相同工艺条件下冷滚打实验得到的工件廓形与仿真结果吻合,验证了仿真结果的正确性,通过合理选择工艺参数可以有效控制回弹,提高制件成形精度。     

An experimental system for release simulation of internal stores in a supersonic wind tunnel

Aerodynamic parameters obtained from separation experiments of internal stores in a wind tunnel are significant in aircraft designs. Accurate wind tunnel tests can help to improve the release stability of the stores and in-flight safety of the aircrafts in supersonic environments.A simulative system for free drop experiments of internal stores based on a practical project is provided in this paper. The system contains a store release mechanism, a control system and an attitude measurement system. The release mechanism adopts a six-bar linkage driven by a cylinder, which ensures the release stability. The structure and initial aerodynamic parameters of the stores are also designed and adjusted. A high speed vision measurement system for high speed rolling targets is utilized to measure the pose parameters of the internal store models and an optimizing method for the coordinates of markers is presented based on a priori model. The experimental results show excellent repeatability of the system, and indicate that the position measurement precision is less than0.13 mm, and the attitude measurement precision for pitch and yaw angles is less than 0.126°, satisfying the requirements of practical wind tunnel tests. A separation experiment for the internal stores is also conducted in the FL-3 wind tunnel of China Aerodynamics Research Institute.     

某型发动机低压压气机导叶角度偏关故障分析与排除

针对某型发动机低压压气机导流叶片角度低于标准值即偏关的故障,详细分析了故障现象,阐述了低压压气机导流叶片调节通道工作原理及控制计划,剖析故障机理。根据所制定的排故流程,提出并分析了可能引发该故障的综合电子调节器、电路、传感器故障模式,最终确定综合电子调节器故障导致低压压气机导流叶片角度低于标准值。更换综合电子调节器,进行外场试车验证。结果表明:发动机工作参数正常,推力稳定,低压压气机导流叶片角度符合要求。     

融合式翼梢小翼减阻效应研究

有效减小诱导阻力对于飞机降低油耗、提高航程具有重要意义。针对某飞机翼身组合体构型,采用CFD数值模拟方法分析融合式翼梢小翼对飞机气动力特性的影响,尤其是其减阻效应;并给出翼梢小翼附近的空间流场。结果表明:带翼梢小翼后翼尖涡强度减弱,飞机阻力系数明显下降;固定升力系数0.5时,弯矩增加3.2%,阻力系数减小4.2%。