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The short- and long-term effects of spacecraft explosions, as a function of the end-of-life re-orbit altitude above the geostationary orbit (GEO), were analyzed in terms of their additional contribution to the debris flux in the GEO ring. The simulated debris clouds were propagated for 72yrs, taking into account all the relevant orbital perturbations.The results obtained show that 6–7 additional explosions in GEO would be sufficient, in the long term, to double the current collision risk with sizable objects in GEO. Unfortunately, even if spacecraft were to re-orbit between 300 and 500km above GEO, this would not significantly improve the situation. In fact, an altitude increase of at least 2000km would have to be adopted to reduce by one order of magnitude the long-term risk of collision among geostationary satellites and explosion fragments. The optimal debris mitigation strategy should be a compromise between the reliability and effectiveness of spacecraft end-of-life passivation, the re-orbit altitude and the acceptable debris background in the GEO ring. However, for as long as the re-orbit altitudes currently used are less than 500km above GEO, new spacecraft explosions must be avoided in order to preserve the geostationary environment over the long term. 相似文献
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L.I. Dorman I.V. Dorman 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2014
A short history of the beginning of cosmic ray (CR) astrophysics is considered: from the hypothesis on CR origin as a result of Supernova explosions in the Metagalaxy, to a model of solar origin of CR, galactic origin based on the stochastic mechanism of charged particle acceleration in interstellar space, to extragalactic and hierarchical models of CR origin, as well as galactic CR origin taking into account radio-astronomical data. We consider also the first balloon results on the chemical contents of primary CR (especially of the contents Li, Be, B), important for any model of CR origin. Investigations of the injection problem, CR drift and diffusion acceleration by shock waves, and CR generation in Supernova remnants were also important steps in the beginning of CR astrophysics. 相似文献
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3-D NUMERICAL SIMULATION OF UNDERWATER EXPLOSION BUBBLE 总被引:10,自引:0,他引:10
Lu Chuanjing 《中国航空学报》1996,(1)
3-DNUMERICALSIMULATIONOFUNDERWATEREXPLOSIONBUBBLELuChuanjing(ShanghaiJiaoTongUniversity,Shanghai,China,200030)Abstract:Thepro... 相似文献
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分子筛供氧爆炸减压过程的数值模拟 总被引:2,自引:1,他引:1
建立了爆炸减压时肺泡氧分压随时间变化的房室数学模型,对于分子筛供氧情况下爆炸减压过程进行了数值模拟,模拟结果和实测结果能够很好的符合.分析了飞行高度及供氧浓度对过程的影响.此模型为求解爆炸减压时肺泡氧分压降到临界值的时间提供了一种简单的方法,对高空飞行医务监督和应急供氧装备的设计有实际意义. 相似文献
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管道相连泄爆容器中粉尘爆炸的实验研究 总被引:2,自引:0,他引:2
采用管道相连容器进行了工业规模的粉尘爆炸实验,目的是研究粮食粉尘在管道相连的加工和输送工业设备中发生粉尘爆炸时火焰和爆炸压力的传播过程及粉尘的Kst值对爆炸的影响。实验装置为一个气力输送系统,由两个不同体积的容器通过管道连接构成。采用粮食工业上具有代表性的两类粉尘进行了粉尘爆炸测试,爆炸从一个容器中通过管道传播到另一个容器中并引发了随后的二次爆炸,测试了不同位置的火焰和压力信号。实验结果表明:即使在起爆容器采取了泄爆措施,管道中没有粉尘喷入的情况下,粉尘爆炸火焰也可沿管道传播达30m并引发二次爆炸;随着粉尘爆炸指数的增大,初始爆炸的猛烈程度增强,火焰传播速度加快,二次爆炸的猛烈程度也随之增强。 相似文献
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