航空发动机风扇转子叶片外物损伤I.鸟撞击试验研究(英文)

本文改进了叶片鸟撞击试验条件。对某型发动机风扇一级转子叶片进行了鸟撞击试验。通过对叶片的鸟撞击瞬态响应分析和撞击前后叶片叶型变化的分析,验证了风扇一级转子叶片的抗鸟撞击性能,为某型发动机风扇转子叶片的抗外物损伤设计提供了依据。     

关于刚体转动的角速度和角加速度的讨论

在理论力学教学中，平面运动刚体的转动与基点无关的证明过于简单，本利用矢量代数的知识，证明平面运动刚体的角度与角加速度与基点的选择无关。     

涡喷发动机加速控制系统数学模型及数字仿真

 本文介绍了航空涡轮喷气发动机加速控制系统数学模型建立、数字仿真方法。由于加速过程是一个大偏离动态过程,因而发动机与加速控制器模型均用非线性方程描述,对非线性方程组求解和系统迭代方法本文进行了讨论。算例中分析了在不同飞行条件下发动机的加速规律。     

MESSENGER: Exploring Mercury’s Magnetosphere

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) mission to Mercury offers our first opportunity to explore this planet’s miniature magnetosphere since the brief flybys of Mariner 10. Mercury’s magnetosphere is unique in many respects. The magnetosphere of Mercury is among the smallest in the solar system; its magnetic field typically stands off the solar wind only ∼1000 to 2000 km above the surface. For this reason there are no closed drift paths for energetic particles and, hence, no radiation belts. Magnetic reconnection at the dayside magnetopause may erode the subsolar magnetosphere, allowing solar wind ions to impact directly the regolith. Inductive currents in Mercury’s interior may act to modify the solar wind interaction by resisting changes due to solar wind pressure variations. Indeed, observations of these induction effects may be an important source of information on the state of Mercury’s interior. In addition, Mercury’s magnetosphere is the only one with its defining magnetic flux tubes rooted beneath the solid surface as opposed to an atmosphere with a conductive ionospheric layer. This lack of an ionosphere is probably the underlying reason for the brevity of the very intense, but short-lived, ∼1–2 min, substorm-like energetic particle events observed by Mariner 10 during its first traversal of Mercury’s magnetic tail. Because of Mercury’s proximity to the sun, 0.3–0.5 AU, this magnetosphere experiences the most extreme driving forces in the solar system. All of these factors are expected to produce complicated interactions involving the exchange and recycling of neutrals and ions among the solar wind, magnetosphere, and regolith. The electrodynamics of Mercury’s magnetosphere are expected to be equally complex, with strong forcing by the solar wind, magnetic reconnection, and pick-up of planetary ions all playing roles in the generation of field-aligned electric currents. However, these field-aligned currents do not close in an ionosphere, but in some other manner. In addition to the insights into magnetospheric physics offered by study of the solar wind–Mercury system, quantitative specification of the “external” magnetic field generated by magnetospheric currents is necessary for accurate determination of the strength and multi-polar decomposition of Mercury’s intrinsic magnetic field. MESSENGER’s highly capable instrumentation and broad orbital coverage will greatly advance our understanding of both the origin of Mercury’s magnetic field and the acceleration of charged particles in small magnetospheres. In this article, we review what is known about Mercury’s magnetosphere and describe the MESSENGER science team’s strategy for obtaining answers to the outstanding science questions surrounding the interaction of the solar wind with Mercury and its small, but dynamic, magnetosphere.     

带摩擦阻尼的叶片响应求解方法

 提出了一种可用于带摩擦阻尼的复杂结构的动力特性的计算方法——动柔度法。给出了计算公式及流程。并用此法对一带摩擦阻尼器的模型叶片进行了稳态响应的计算。通过理论计算并与实验对比表明,动柔度法是一种可用于复杂结构响应计算的高效的算法。由于叶片与阻尼器之间有复杂的运动关系,在用于带阻尼器的叶片的响应计算及阻尼器优化设计时,此法将更显优越。     

SRM 纤维缠绕壳体的蒙特卡罗随机有限元分析

采用蒙特卡罗随机有限元方法，结合复合材料壳体力学、纤维缠绕理论等知识，分析了固体火箭发动机纤维缠绕壳体在燃气内压随机变化作用下的应力响应，绘出应力分布曲线，为固体火箭发动机结构可靠性评估奠定基础。     

直升机振动响应计算方法研究

在直升机研制阶段,预测全机振动响应是控制直升机振动水平的关键技术。本文建立了利用频响传递函数实测数据,对全机振动分析有限元模型进行修正的方法,机体的振动响应预测结果与实测结果具有很好的一致性,达到了较高的精度。通过研究,探索出了一套直升机结构振动响应模型修改和分析技术,为直升机振动响应预测提供了一种有效的分析手段,也为深入开展直升机振动响应预测研究奠定了基础。     

仿真与响应曲面法的结合及其在综合生产计划中的应用

 论述响应曲面法与仿真相结合的优化结构,着重讨论了一阶和二阶响应曲面的仿真拟合原理和寻优过程,从而可在仿真环境下给出最优决策参数。利用所开发的GASPRSM仿真优化软件,对飞机工厂生产计划安排进行了仿真运行,证明可以取得显著的经济效果。     

平板叶片斜撞击瞬态响应的计算分析

采用有限元法,对平板叶片在不同鸟撞击角度下的非线性瞬态响应进行了数值分析研究.结果表明,平板叶片在不同撞击角度下的弯曲变形、到达最大变形的时间及残余变形随着撞击角度的增加而增大;平板叶片的扭转变形随着撞击角度的增加先增大后减少,撞击角度在小于30°及90°附近对平板叶片的扭转变形影响很小.     

有效载荷／运载火箭耦合分析的频域方法

盘算尖响函数综合技术导出了用耦合频响函数和无有效载荷的运载火箭界面加速度响应表示的有效载荷／运载火箭耦合动力分析的频域方法，给出了以自由界面的运载火箭模态分数放自由界面或固定界面有效载荷模态参数构成的耦合频响函数表达式。