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稀土永磁的商品化现状与工艺上的新进展 总被引:2,自引:0,他引:2
描述了国内外NdFeB永磁材料的商品化现状及未来发展方向。为克服NdFeB永磁的某些局限性及提高其磁性能,重点介绍了近年来在工艺上优化合金组成与实现加工改性方面所做的大量工作,指出开发粘结型NdFeB是我国永磁产业的主要发展方向。 相似文献
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着重讨论了AlNiCo、R-Co、Nd-Fe-B及Sm-Fe-N等金属永磁材料的发展与研究现状,对各种合金的性能与应用前景进行了评价。此外,简单介绍了FeCrCo、FeCoV及MnAlC永磁材料。并展望了磁性材料的未来发展趋势。 相似文献
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介绍了下一代地铁车辆用TQ250永磁同步牵引电机的研制情况。主要从总体技术要求、设计难点、关键技术、样机试验等方面进行了论述。根据下一代地铁车辆永磁同步牵引电机的技术特点及主要技术参数指标要求,通过对等效定额设计、电磁设计、轻量化设计及冷却结构设计等关键技术攻关,研制了1台永磁同步牵引电机,并进行了试验。样机试验结果分析表明,该电机满足下一代地铁车辆指标要求,验证了所设计的可行性。 相似文献
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为了实现电推进飞机电机的高功率密度和高效率,提出了一种无槽轴向磁场永磁电机,该电机在继承定子无铁心轴向磁场永磁电机高效率优势的同时,能够实现更高的功率输出能力。首先,阐述了3种轴向磁场永磁电机的拓扑结构,包括定子无铁心轴向磁场永磁电机、无槽轴向磁场永磁电机及无轭分块电枢轴向磁场永磁电机。在此基础上,分别对3种电机的绕组因数、转矩输出能力和损耗分布进行了深入分析,对其损耗产生机理和影响因素进行了研究。针对飞机推进电机应用场合,对3种电机的电磁特性进行了对比。结果表明,提出的无槽轴向磁场永磁电机具有高功率密度和高效率的优势,适合应用于电推进飞机。最后,研制了一台50 kW定子无铁心轴向磁场永磁电机原理样机,试验结果验证了理论和仿真分析方法的正确性。 相似文献
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高速非晶合金永磁电机设计受电磁、机械、温升的制约,因此高速非晶合金永磁电机的设计是一个多物理场综合设计的过程。针对高速非晶合金永磁电机设计受多物理场制约的问题,基于多物理场的分析方法,分析了非晶合金材料对高速永磁电机电磁性能的影响;研究了内置式永磁转子在高速运行状态下的应力分布,并分析了轴承支撑刚度对转子系统临界转速的影响;针对高速非晶合金永磁电机损耗分布特点研究了其温度场的分布。基于提出的多物理场综合设计方法,设计并制造了一台额定功率15 kW、最高转速30 000 r/min的高速内置式非晶合金永磁电机,并对样机进行了试验,验证了仿真分析与设计方法的可行性,为高速非晶合金永磁电机的设计提供参考。 相似文献
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高速电机具有高功率密度、能够减小设备体积与重量,可以直接驱动负载、提高传动效率,在航空航天、新能源、精密制造等领域具有广阔的应用前景。将无轴承永磁电机应用于高速驱动系统,在推导无轴承永磁电机数学模型基础上,提出了高速无轴承永磁电机设计方法。通过对一台额定功率2 300 W、额定转速8 000 r/min、调速范围0~60 000 r/min的高速无轴承永磁电机进行电磁和机械一体化设计,并采用有限元法对样机的电磁性能和动力学性能进行优化。仿真试验结果验证了所采用的设计方法的正确性。 相似文献
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研究了Fe对XD工艺原位生成NiAl-TiB2复合材料室温压缩性能的影响及其微观机制。加入25at%Fe元素后,其室温压缩变形量可达20%。分析透射电子显微术和高分辨透射电子显微术研究表明,NiAl(Fe)-TiB2复合材料中,除β-Ni(Al,Fe)、γ′-(Ni,Fe)3Al相及TiB2颗粒外,还生成了一种新的Fe(Ni,Al,Ti)相。和基体相比,该相有较高的Fe含量,分布于枝晶间,可提高材料的塑性。Fe(Ni,Al,Ti)相属面心立方结构,点阵常数为a=1.068nm,它与基体和增强颗粒之间结合紧密,界面无反应产物。 相似文献
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《中国航空学报》2021,34(9):168-177
To investigate the effect of tip clearance size on cavitation characteristics in a turbopump inducer, a series of experiments have been conducted in a newly developed visualization test facility using room temperature water as working fluid. The pressure fluctuations near the tip region were collected, and the cavity structures under various conditions were documented by a high-speed camera. It is found that large tip clearance distinctly reduces both the non-cavitation and cavitation performance. Three cavitation instabilities, super-synchronous rotating cavitation, synchronous rotating cavitation and cavitation surge have been carefully identified through combination of cross-correlation analysis of pressure signals and visualization results. Large tip clearance displays a remarkable stabilization effect on pressure fluctuation, cavitation surge totally disappears, and the range of occurrence of synchronous rotating cavitation becomes smaller for the large tip clearance, whereas super-synchronous rotating cavitation only occurs in the large tip clearance. The cavitation areas are smaller at large tip clearance, while the flow channels are more seriously choked when cavitation occurs heavily in comparison with those at small tip clearance, which may be responsible for the worse cavitation performance. 相似文献
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火焰筒多斜孔冷却方式壁温梯度和冷却效率试验 总被引:4,自引:0,他引:4
针对高温升燃烧室以延长其火焰筒使用寿命为目的,实验研究了多斜孔冷却方式孔排列方式、壁厚与孔径比h/d以及无量纲参数PS/d2对主燃烧室采用多斜孔冷却方式的火焰筒壁温梯度和冷却效率的影响.实验中冷却气为常温常压,主流速度ug≈20 m/s,多斜孔内气流与主流速度比约为0.66,主流与冷却气温度比约为1.2.实验结果表明:长菱形多斜孔实验板比正菱形实验板壁温梯度小、冷却效率高;减小h/d或者增大PS/d2都可以降低壁温梯度,但同时冷却效率也会降低. 相似文献
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Taira S. Tanaka M. Ohmori S. 《IEEE transactions on aerospace and electronic systems》1991,27(2):354-360
The performance of an airborne phased-array antenna, which was developed and evaluated onboard a commercial aircraft using the Engineering Test Satellite V (ETS-V), is reported. The system requirements and the antenna configuration that satisfies them are described. The radiation pattern, gain and axial ratio, noise temperature and ratio of gain to noise temperature, and environmental characteristics are presented. The results obtained by the flight experiments demonstrate that the performance of the antenna is the same as that on the ground, so that the antenna is suitable for installation in an aircraft for satellite communications 相似文献
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航空高性能齿轮钢的研究与发展 总被引:1,自引:0,他引:1
评述了国内外高性能航空齿轮钢的研究与发展状况.齿轮钢经历了由高硬度、常温使用进而高硬度、中温使用到超高硬度、高韧性、耐腐蚀、高温使用三代发展.发展高性能齿轮钢、高纯熔炼和先进的相关设计、加工技术是达到高承载、长寿命齿轮的必由之路. 相似文献
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复合材料在红外隐身技术中的应用 总被引:1,自引:0,他引:1
根据红外隐身原理,将应用于红外隐身技术的复合材料进行分类阐述,分析复合材料在红外隐身技术中的地位和应用前景,并着重介绍了本实验室在基于热电制冷器(TEC)的智能温控复合材料系统方面的研究成果。研制了针对不同具体应用条件的多种智能温控复合材料系统;建立了智能温控复合材料系统的制冷性能理论计算模型;并考察TEC热电元件臂长、TEC热端散热方式等因素对系统温控效果的影响,进一步优化了智能温控效果,使该智能温控材料能够根据设定温度的复杂变化做出快速响应。最后对智能温控复合材料在红外隐身技术中的应用进行了总结和展望。 相似文献
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《中国航空学报》2023,36(2):87-99
Ice accretion on aircraft encountering supercooled water droplets in clouds poses great risks to flight performance and safety. With the aim of optimizing the newly developed streamwise plasma heat knife method for anti-icing, a parametric investigation is carried out in this work. The influence of the detailed voltage profile on the heating effects of a Surface Dielectric Barrier Discharge driven by Nanosecond Pulses (NS-SDBD) is investigated, and a comparison of the anti-icing performance among different configurations of streamwise plasma heat knife is made. The results show that columnar high-temperature regions produced by a multi-streamer discharge appear at small pulse rise time, but become diffuse as the pulse rise time increases. An optimal pulse rise time exists to provide a wide range and high value of temperature, which is found to be 150 ns for the setup in the present study. The influence of the pulse fall time is much weaker than that of the rise time. The range and value of the temperature decrease with increasing pulse fall time. A greater pulse width is found to improve the heating effect by increasing the discharge power. When a spanwise electrode is placed connecting the streamwise electrodes of the streamwise plasma heat knife at the airfoil leading edge, the anti-icing performance becomes poorer, whereas good performance is achieved when the spanwise electrode is at the edge of the streamwise electrodes. Based on this, a three-level configuration of the plasma heat knife is proposed, and its anti-icing performance is found to be much better than that of the original configuration. 相似文献
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Dynamic analysis of flexible multibody systems is complex. Several successful methods have been demonstrated. However, few works discussed the dynamic performance of the flexible multibody under different temperatures. This paper uses the absolute nodal coordinate formulation to analyze the flexible body dynamics of deployment structures under different temperatures to simulate space environments. The dynamic equations of finite element in temperature field are developed. Then a computer-aided simulation of flexible multibody systems in temperature field is implemented. A general four-bar mechanism under different temperatures as a simulation example is demonstrated, and the deployment characteristics of a special four-bar mechanism as a basic module of the hoop truss deployable antenna is analyzed under different temperatures in order to evaluate the dynamic performance of the deployable antenna in space environments. The simulation results indicate the influence factors of deployment dynamic characteristics include the structural form, material properties, geometric parameters and deployment planning in ambient and thermal/vacuum environments. 相似文献
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临界冰形确定方法及其对气动特性影响研究 总被引:1,自引:0,他引:1
临界冰形是指在适航规章结冰包线内,每个可用飞行构型下,对飞机操纵性和稳定性影响最严重的冰形,临界冰形分析是飞机适航取证中的重要工作。对临界冰形确定方法,及临界冰形对气动特性的影响进行了研究。发展了基于 CFD 方法计算临界冰形的一般方法,包括临界冰形分析状态、敏感性分析截面确定、结冰参数敏感性分析、临界结冰条件确定、临界冰形确定等。流场计算采用中航工业空气动力研究院气动力计算平台(UNSMB),基于 Jameson 中心格式的有限体积法求解 N-S 方程;水滴撞击特性计算采用 Eulerian 方法求解水滴轨迹运动方程;结冰计算采用经典的 Messinger 热力学模型。选取 CRM 飞机为研究对象,以机翼外翼50%展长处为敏感性分析截面,在典型飞行条件下,分析了结冰对环境温度、水滴直径、飞行速度、飞行迎角等参数的敏感性。利用“几何外形敏感性分析方法”,即通过对比冰形的上下冰角角度和冰角厚度等冰形几何参数来确定最严重冰形,得到了CRM 飞机的临界结冰条件和临界冰形,其中敏感性分析截面在水滴直径为30μm 时上冰角厚度和下冰角厚度最大,冰角最大厚度约41 mm。计算了结冰后的气动性能衰减规律,临界冰形对飞机气动性能影响严重,导致升力降低6.7%~23.8%,阻力增加17%~70.9%。发展了45min 待机临界冰形确定方法,基于几何外形敏感性分析方法进行环境温度、水滴直径、飞行条件等各类参数的结冰敏感性分析,得到飞机的临界结冰条件和临界冰形,对于民用飞机设计和适航取证具有一定的工程应用价值。 相似文献