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Sounding rocket experiment of bare electrodynamic tether system 总被引:1,自引:0,他引:1
Hironori A. Fujii Takeo Watanabe Hirohisa Kojima Koh-Ichiro Oyama Tairo Kusagaya Yoshiki Yamagiwa Hirotaka Ohtsu Mengu Cho Susumu Sasaki Koji Tanaka John Williams Binyamin Rubin Charles Les Johnson George Khazanov Juan R. Sanmartin Jean-Pierre Lebreton Erick J. van der Heide Michiel Kruijff Fabio De Pascal Pavel M. Trivailo 《Acta Astronautica》2009,64(2-3):313-324
An overview of a sounding rocket, S-520-25th, project on space tether technology experiment is presented. The project is prepared by an international research group consisting of Japanese, European, American, and Australian researchers. The sounding rocket will be assembled by the ISAS/JAXA and will be launched in the summer of 2009. The sounding rocket mission includes two engineering experiments and two scientific experiments. These experiments consist of the deployment of bare electrodynamic tape tether in space, a quick ignition test of hollow cathode system in space, the demonstration of bare electrodynamic tether system in space, and the test of the OML (orbital-motion-limit) current collection theory. 相似文献
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火箭引射模态下一次火箭流量优化方法研究 总被引:4,自引:0,他引:4
对火箭基组合循环(RBCC)发动机火箭引射模态下一次火箭流量优化方法开展了研究,并对飞行条件下一次火箭流量的变化规律进行了分析。提出了采用有效比冲作为优化目标的一次火箭流量单目标优化模型;建立了求解与一次火箭流量相匹配的二次燃料流量的比例控制方法;在考虑发动机性能优化与弹道分析耦合作用的基础上,采用试验设计和遗传算法,建立了火箭引射模态下一次火箭流量优化方法。针对空中载机发射的RBCC发动机,开展了火箭引射模态下一次火箭流量优化,并根据弹道分析结果,给出了飞行条件下一次火箭流量变化规律。结果表明,为了克服飞行过程中声障阻力,一次火箭流量在Ma=1.0附近达到最大,此时对发动机提出较高的推力设计要求;在Ma=1.5附近,来流空气的冲压作用占主导地位,一次火箭流量出现较大程度的节流,此时对发动机提出较高的比冲设计要求;超过Ma=1.5后,一次火箭以较小的流量状态维持稳定工作;火箭引射模态下一次火箭流量调节比达到了5.0。 相似文献
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火箭引射模态下主火箭总压与RBCC发动机的匹配性 总被引:4,自引:0,他引:4
基于传统的"等压面假设"理论,建立了RBCC发动机主火箭的引射性能分析模型,研究了主火箭总压与RBCC发动机的匹配性。研究结果表明,若隔离段通道面积比小于0.65,在主火箭总压较低条件下,隔离段内二次流容易达到壅塞,无法进一步提高空气流量;在地面静止状态下,随主火箭总压增加,空气流量逐步增大,等压面上形成Fabri壅塞后,进一步增加主火箭总压,反而会降低空气流量;在火箭引射模态下,RBCC发动机的工作状态可细分为引射作用占主导地位的进气道亚临界状态和临界状态、冲压作用占主导地位的进气道超临界状态,其分界马赫数分别约为0.7和1.5。 相似文献
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F. Winterberg 《Acta Astronautica》1985,12(3):155-161
A novel propulsion concept is proposed which has the potential of accelerating large masses to velocities substantially higher than what is possible with chemical rockets. The novel concept is an electromagnetic gun, where the projectile is a rocket. The proposed concept solves the old problem of magnetic propulsion, which is the resistive dissipation of the induced electric currents into heat which will vaporize the projectile long before it can reach a high velocity. As in a rocket, where the propellant cools and thereby prevents the rocket from burning up, the same happens in the proposed concept where the propellent also cools the projectile and prevents its vaporization. The propellant, however, not only cools the projectile but in addition is resistively heated by the magnetic field and ejected from the projectile with high velocity. The resulting recoil produces an additional thrust which is approximately as large as the thrust exerted by the magnetic field alone. The energy to drive the jet is externally supplied, making the specific impulse much larger than for chemical rockets. 相似文献
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20世纪的中国火箭控空 总被引:1,自引:0,他引:1
火箭探空是中国发展航天事业的起步项目之一,也是中国在高新技术中较早达到国际水平和进入实用阶段的一个领域。中国于1958年开始发展探空火箭。在研制发射了几种型号的早期研究、试验性探空火箭的基础上,中国的第一种实用探空火箭于1960年9月首次飞上蓝天。在 20世纪,中国共研制成功19种实用火箭探空系统,富有成效地进行了气象探测、核云取样、人造卫星和运载火箭单元技术试验等火箭探空活动。 相似文献
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《Acta Astronautica》1987,15(2):97-104
Results of experiments performed with an advanced, automated measuring system and dealing with combusion of polymethylmethacrylate and polyethylene with oxygen and different mixtures of oxygen and nitrogen are reported.Factors affecting the regression rate of the fuel are the mass flux, the geometry, the pressure level and the presence of oscillations, the composition of the oxidizer and the burning time. The effect of pressure on the regression rate appears to be stronger at lower pressures. A newly developed technique allows the measurement of the local instantaneous regression rate. The dependence of this regression rate on the various above mentioned parameters varies from location to location in the motor. The characteristic velocity depends on the mixture ratio and on the residence time of the reacting gases. A rearward facing step increases the mean regression rate and changes the profile of the burned fuel grain. Such a step is necessary to obtain combustion with mixtures containing 20% oxygen and 80% nitrogen. 相似文献
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Hydrogen being an ecological fuel is very attractive now for rocket engines designers. However, peculiarities of hydrogen combustion kinetics, the presence of zones of inverse dependence of reaction rate on pressure, etc. prevents from using hydrogen engines in all stages not being supported by other types of engines, which often brings the ecological gains back to zero from using hydrogen. Computer aided design of new effective and clean hydrogen engines needs mathematical tools for supercomputer modeling of hydrogen–oxygen components mixing and combustion in rocket engines.The paper presents the results of developing verification and validation of mathematical model making it possible to simulate unsteady processes of ignition and combustion in rocket engines. 相似文献
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《固体火箭技术》编辑部 《固体火箭技术》2022,45(1):1-3
从本刊刊载情况看,2021年对于固体火箭发动机技术及其相关领域的发展有几个值得一提的事情.首先,我国自主研发的?3.2 m分段式固体火箭发动机和?3.5 m整体式复合材料缠绕固体火箭发动机相继试车成功,标志着我国打通了?3 m以上大型固体火箭发动机研制的关键技术链路;其次,2021年在以超燃、推力可调可控特种发动机等为... 相似文献
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针对可靠性设计没有数据导致可靠度无法计算的困难,提出放弃可靠度而使用事件流分析来控制产品可靠性的方法,该方法将产品主事件分解为一系列的事件,任何一个事件都可以分为应力(L)、应构(G)、应变(B)和传递(D)4个要素,每个要素都可以提出一些可测量的工作控制指标,只要能够确保每个工作控制指标符合设计意图,就能控制产品不出现故障。根据这种观点,提出了发动机可靠性设计的事件流分析技术,先按照事件发生顺序一步步地分析产品工作中会发生的各种事件,每个事件都用LGBD的结构展开,然后分析监测每个要素需要的测量参数,以及控制每个要素需要的设计参数,从而确定完备的工作控制指标体系,并确定可靠性试验方案。该方法放弃了可靠性模型,代之以事件流模型,为可靠性设计提供一种全新方法。 相似文献
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Giovanni Vulpetti 《Acta Astronautica》1985,12(2):81-90
The maximum terminal velocity problem of the classical propulsion is extended to a relativistic rocket assumed broken down into active mass, inert mass and gross payload. A fraction of the active mass is converted into energy shared between inert mass and active mass residual. Significant effects are considered. State and co-state equations are carried out to find the exhaust speed optimal profile.A first major result consists of a critical value of inert mass. Beyond it both true and effective jet speeds increase with time. Below it the true jet speed profile is reversed. At criticality, the best control consists of both velocities constant in time.A second meaningful result is represented by an interval of inert mass outside which no optimal control exists. Numerical results are discussed with particular emphasis to current concepts of antimatter propulsion. 相似文献
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Trial of hands-on education of rocket technology for university students using water rocket, which consists of structural study, propulsion system study, aerodynamic study, stability study, and flight trajectory study, has been performed. Integrating each subject into a group of tasks, a hands-on education system of aerospace technology will become feasible. Advantage of the system is that students can verify the theory by hands-on practice. Development of recovery mechanism for water rocket will be a good subject of hands-on innovative design. Although the system has been developed mostly for university students, it can easily be converted to hands-on education system for school children and high school students. 相似文献