共查询到19条相似文献,搜索用时 250 毫秒
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离子液体电喷推力器易于小型化,具有比冲高、推力精度高的特点,适用于微小卫星、太空引力波探测等领域,具有较大发展潜力。对电喷工作机理的认识与研究,不仅能够促进离子液体电喷推力器在工程中的应用,同时也为未来的进一步发展奠定基础。基于此,本文首先回顾了电喷推力器的发展历程及现状;其次以离子液体电喷推力器3个基础工作过程为出发点,对其锥射流形成及发射机理、束流模式及引出特性、羽流自中和机制进行了基础理论介绍与研究现状的总结;最后对离子液体电喷推力器未来的工作机理研究方向和工程应用发展方向提出展望。 相似文献
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射频离子推力器是空间电推进的一种,其推力性能是系统设计的核心问题。为获得推力特性随设计参数的变化规律,采用数值计算方法进行了研究,开展了1 mN射频离子推力器设计计算,对不同放电室尺寸、流量、射频功率、屏栅电压下的推力性能进行了分析并进行了工况优化。结果表明,模型能够正确地描述射频离子推力器性能变化规律,放电室内径25 mm的推力器即可以实现1 mN推力指标,在最优工况下,推力器推力1.176 mN,比冲2 503 s,效率53.13%,满足设计要求。根据该模型研制的推力器样机成功点火,验证了数值模型的有效性,可以利用该模型为射频离子推力器研制工作提供指导。 相似文献
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针对固体微推力器阵列(SPMA)中微推力器一次性点火,推力测试中难以获得精确推力的特点,为实现推力在线估计和实时补偿,提出一种利用二次规划对微推力器阵列推力进行估计,同时结合混合整数规划算法进行推力分配的方法,对估计算法收敛性以及控制系统稳定性进行了分析。该方法在不修改控制律的前提下,对推力器推力进行在线估计,并采用推力分配的方法实时补偿推力器出现的推力偏差,对系统稳定性的分析证明该方法可以保证系统的有界稳定。将其应用到微纳卫星编队保持中,仿真结果表明,在微推力器阵列出现推力偏差的情况下,该方法能很好地补偿推力偏差对控制系统造成的影响。 相似文献
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为了给微纳卫星在轨动作提供合适的推力,研制了一种同轴型微阴极电弧推力器(CA-μCAT),采用同轴布置的棒状阳极和圆筒形阴极,利用真空环境下电弧放电产生的高温烧蚀金属阴极,电离产生等离子体,并在多物理场耦合作用下高速喷出推力器产生推力。文章分别对该推力器的放电特性、推进剂烧蚀速率、等离子体离子电流、元冲量等多个参数进行了测量与分析。结果表明,该推力器能够持续稳定点火运行,电离率在4%~7%;无外加磁场下,元冲量和比冲分别为0.485μN·s和195.6 s;在磁感应强度为0.044 T时,元冲量和比冲分别为1.285μN·s和518.2 s;平均推力在10μN量级。 相似文献
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C/SiC复合材料推力室应用研究 总被引:2,自引:0,他引:2
C/SiC复合材料密度低、耐高温、抗氧化、抗烧蚀,并且具有非常好的高温力学性能,是制备高性能液体火箭发动机推力室的理想材料.本文从C/SiC复合材料燃烧室结构计算、无损探伤及C/SiC与金属连接等方面,论述了上海空间研究所在C/SiC复合材料应用于液体火箭发动机推力室方面的基础研究及应用进展. 相似文献
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以过驱动航天器的推力器控制分配误差最小、推力器负载均衡等为设计目标,构建航天器推力分配混合优化模型,并将其转化为线性规划模型进行求解,提出了一种考虑负载均衡的航天器推力器动态分配算法。该算法在确保分配误差最小前提下,能够降低各推力器的最大分配推力之差,有效均衡各推力器总工作时长和开关次数,进而延长推进系统的整体工作寿命。进一步定义了表征负载均衡性能的推力平衡度和干扰敏感度性能指标,并在此基础上给出了一种分配算法负载均能能力的定量化评价方法。在仿真验证中,采用平衡度和敏感度对算法性能进行定量评估,结果表明该方法在保证控制性能和控制分配误差的前提下,能够有效均衡各推力器最大推力,提高了系统的平衡度和对扰动力矩的鲁棒性。 相似文献
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Experiments and numerical simulations of an electrodynamic tether deployment from a spool-type reel using thrusters 总被引:3,自引:0,他引:3
The amount of space debris is ever increasing, and pollution of the space environment has become a serious problem that can no longer be ignored. Consequently, the active removal of large space debris from crowded economically useful orbits should begin as soon as possible. The Japan Aerospace Exploration Agency has been investigating an active debris removal system that employs highly efficient electrodynamic tether (EDT) technology for orbital transfer. This study investigates the tether deployment from a spool-type reel using thrusters by means of numerical simulations of an EDT system. The thrusters are used in order to ensure the deployment of a tether with the length of several kilometers. In the simulations using a multiple mass tether model, the key parameters are estimated from various on-ground experiments. By means of the numerical simulations, the dynamics of tether deployment is studied and requirements of thruster needed for the deployment, such as the thrust forces and the periods of thruster activation, are clarified. 相似文献
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A theoretical analysis considering the capabilities of nano electrokinetic thrusters for space propulsion is presented. The work describes an electro-hydro-dynamic model of the electrokinetic flow in nano-channels and represents the first attempt to exploit the advantages of the electrokinetic effect as the basis for a new class of nano-scale thrusters suitable for space propulsion. Among such advantages are their small volume, fundamental simplicity, overall low mass, and actuation efficiency. Their electrokinetic efficiency is affected by the slip length, surface charge, pH and molarity. These design variables are analyzed and optimized for the highest electrokinetic performance inside nano-channels. The optimization is done for power consumption, thrust and specific impulse resulting in high theoretical efficiency ∼99% with corresponding high thrust-to-power ratios. Performance curves are obtained for the electrokinetic design variables showing that high molarity electrolytes lead to high thrust and specific impulse values, whereas low molarities provide highest thrust-to-power ratios and efficiencies. A theoretically designed 100 nm wide by 1 μm long emitter optimized using the ideal performance charts developed would deliver thrusts from 5 to 43 μN, specific impulse from 60 to 210 s, and would have power consumption between 1–15 mW. It should be noted that although this is a detail analytical analysis no prototypes exist and any future experimental work will face challenges that could affect the final performance. By designing an array composed of thousands of these single electrokinetic emitters, it would result in a flexible and scalable propulsion system capable of providing a wide range of thrust control for different mission scenarios and maintaining very high efficiencies and thrust-to-power ratio by varying the number of emitters in use at any one time. 相似文献
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航天器推力系统发动机数目及其构型的选择直接影响控制系统的精度和完成要求任务的燃料消耗量.对航天器六自由度控制的推力分配问题进行了研究,参考卫星导航系统中几何精度衰减因子的定义,提出了发动机构型精度衰减因子的概念,用于定义发动机相对几何关系引起的执行误差与分配误差间的比例关系.通过矩阵理论分析得到了构型精度衰减因子随参与分配发动机数目增加而增加的结论,并通过仿真计算对相关结论进行了验证,为航天器发动机数目及其构型的选择提供了理论参考. 相似文献