【摘 要】
:
Aircraft icing has long been a plague to aviation for its serious threat to flight safety.Recently,researches about a newly proposed deicing method based on Plasma Synthetic Jet Actu-ator(PSJA)have just started.To meet the requirements of in-flight deicin
【机 构】
:
College of Aerospace Engineering,National University of Defense Technology,Changsha 410073,China;Chi
论文部分内容阅读
Aircraft icing has long been a plague to aviation for its serious threat to flight safety.Recently,researches about a newly proposed deicing method based on Plasma Synthetic Jet Actu-ator(PSJA)have just started.To meet the requirements of in-flight deicing,structure of PSJA needs to be adjusted.This paper completed the detailed design and experimental validation of a novel plasma striker,which was a modified version of PSJA.Influences of mass of the moving part and rod shapes on the ice-breaking performances were also studied.Besides,a“conical-nosed rod configuration”was proposed.Its purpose was to ensure a good ice-breaking performance of the plasma striker on long ice,by generating a splitting failure.Results show that,though mass of the moving part was just several grams,ice-breaking performance was better when the mass was lighter.The rectangular rod could generate an elliptical circumferential crack,whose major axis was parallel to the direction of the long side of the rectangular rod.And the“conical-nosed rod”concept was verified to be able to generate a splitting crack which can spread completely to the far end of long ice,and the crack direction was parallel to edge line of the cone.In general,the plasma striker has the advantages of simple structure,low energy consumption,little harm to the flow field and the aircraft skin.Simulations will be carried out in future works to study in detail the working process of the plasma striker.
其他文献
以水滑石(LDH)为载体,山梨酸钾(SBA)和SBA-十二烷基硫酸钠(SDS)为客体插层分子,通过焙烧复原法制备SBA-LDH和SBA-SDS-LDH两种插层复合材料.采用傅里叶变换红外光谱(FTIR)、X射线粉末衍射(XRD)、扫描电镜(SEM)和热重-差热分析(TG-DSC)对插层材料的结构和热稳定性进行表征和分析,并考察其在不同pH缓冲溶液体系中的缓释性能.结果表明,SBA和SBA-SDS能够插入到LDH板层间,客体阴离子以长轴垂直的方式排列.两种材料在pH为4.4和3.4的缓冲体系中均表现出良好的
Hemispherical Resonator Gyroscope(HRG)is a classical high precision Coriolis Vibration Gyroscope(CVG),which performs attitude estimation of carrier by detecting the precession of standing wave of resonator,thus,the drift of standing wave of resonator has
As one of the promising configurations of the next generation of commercial aircraft,research on departure characteristics of the Blended-Wing-Body(BWB)is of great signification to safe flight limits.A three-degree-of-freedom(3-DOF)virtual flight test in
通过阅读相关文献,提取出8个影响建筑业转型升级的因素,用灰色关联理论计算出各因素与建筑业转型升级的关联程度,然后用AHP法计算出各因素的权重.根据算例分析的结果可以看出,各因素对建筑业的转型升级都有一定的影响,其中,影响较大的因素分别为政府出台的相关政策、技术创新能力、市场管理因素,并在此基础上提出一些针对性的对策建议.
由于燃料电池混合动力皮卡车能量转化效率高、无污染且续航里程理想,其逐渐成为未来皮卡市场的发展趋势.基于Cruise-Simulink联合仿真平台对某款皮卡车进行整车建模,采用一种燃料电池与蓄电池混合的动力系统,通过仿真曲线进行分析,结果表明:本款皮卡车在最高车速、续航里程、爬坡度以及耗能经济性方面均符合设计要求且优于原型燃油车.
The underlying study investigates single valued neutrosophic entropy based adaptive sensitive frequency band selection for variational mode decomposition(VMD)for the purpose of identifying defective components in an axial pump.The proposed methodology is
城市经济社会的快速发展带动城市区域的扩大,而防洪排涝能力不足却严重阻碍各省区市的经济发展,因此,区域防洪排涝的绩效水平愈发成为人们关注的热点和焦点.文中采用SPSS系统的因子分析和聚类分析对中国31个省区市的防洪排涝事业进行评价与比较.通过因子分析得出各省区市防洪排涝绩效的综合得分偏低,并分析其年际间绩效和排名的变化及原因.通过聚类分析将各省区市防洪排涝事业的发展划分为四大类,并对不同类别进行比较分析,根据所得结果对不同区域给予针对性的建议.
恩格斯晚年通过对资本主义世界发展新形势的观察,在明确表达不放弃暴力革命这一原则性立场的基础上,肯定了合法斗争的社会革命意义及其现实作用,但是这引发了后世的不断讨论.从整体性的角度探讨恩格斯晚年社会革命思想是回应学术界的误解并澄清恩格斯晚年思想科学性的重要途径,为此不仅要抓住暴力革命和议会斗争这两点,还要立足于加强无产阶级政党建设和树立革命信心这两个方面.恩格斯晚年社会革命思想对我国新时代推进伟大社会革命具有重要的指导意义.
新工科建设是基于国家战略发展新需求而提出的我国高等工程教育改革的新方向.基于新工科建设背景,文章以“数字测图原理与方法”为研究对象,立足工程教育认证理念,分析测绘工程专业课程体系面临的问题,对课程建设、教学改革进行研究探索.采取“线上线下混合教学、项目案例教学、综合考核”教学模式,课程思政引导、学科竞赛引领的自主学习模式,为测绘工程专业人才培养体系的持续改进优化提供有效支撑.
Hypersonic high-enthalpy wind tunnels have been a challenge to ground tests in aero-space research area for decades and its test flow uniformity is one of the most important parameters for evaluating wind tunnel performances.Regarding to the performance r