Design of hybrid-electric aircraft with fault-tolerance considerations

The potential benefits of hybrid-electric or all-electric propulsion have led to a growing interest in this topic over the past decade. Preliminary design of propulsion systems and innovative configurations has been extensively discussed in literature, but steps towards higher levels of technological readiness, optimisation algorithms based on reliable weight estimation and simulation-based mission analysis are required. This paper focuses on the integration of a method for evaluating the lateral-directional controllability of an aircraft within a design chain that integrates aero-propulsive interactions, accurate modelling of the fuel system, and mid-fidelity estimation of the structural weight. Furthermore, the present work proposes a strategy for powerplant management in scenarios with an inoperative chain element. Benefits of hybrid-electric propulsion on the design of the vertical tail plane are evaluated involving the analysis of multiple failure scenarios and certification requirements. The proposed application concerns a commuter aircraft.     

航空用不锈钢磨粒流光整加工表面完整性研究

为研究磨粒流光整加工不锈钢闭式整体叶环的表面完整性，通过对电火花制备的不锈钢试样进行加工时间、加工压强及磨料目数的单因素试验，研究3个因素对加工后表面完整性的影响。结果表明：表面粗糙度Ra随着加工时间的增加而降低，从初始时的1.459μm降至60 min时的0.193μm，降低速率越来越慢，最后趋于稳定。磨粒流加工有效去除了加工表面再铸层。显微硬度在加工后明显降低，由450～950 HV降至270～350 HV且分布均匀性得到改善。显微硬度随着加工时间的增加整体上呈降低趋势，并出现了一定的加工硬化现象。在使用不同目数的磨料进行磨粒流加工后，残余应力由拉应力变为压应力。随着加工时间和加工压强的增加，试样表面越平整，抛光效果越好。     

空间低频射电天文天线材质-观测性能分析

15MHz以下的射电天文信号由于受到电离层的阻挡只能通过空间卫星平台进行观测。采用空间展开的电小天线是目前普遍的做法。就电小天线的材质-接收性能方面进行分析，构建了基于材质磁导率、电导率对后端接收机噪声影响模型。通过计算结果比对和就天线材质空间展开难易程度的综合考虑，归纳总结了不同材质对空间低频射电天文观测噪声影响以及展开难度，为新天线的研制提供了数据依据。该项工作将为下一步L1点空间天气监测卫星中的太阳射电观测载荷提供技术支持。     

我国空间推进技术研究现状及发展

空间推进是航天器实现轨道机动和姿态控制的动力源.经过60多年的发展,我国在空间推进方面逐步掌握了化学推进、电推进、在轨补加等一系列关键技术,实现了从常规有毒向新型无毒的转变,以及从化学能推进向更高能量密度推进的升级,形成了型谱化空间推进产品,并成功应用于我国运载火箭、载人航天、人造卫星、深空探测、空间防务等领域,支撑了...