Fundamentals of the Plasma Sail Concept: MHD and Kinetic Studies
Fundamentals of the Plasma Sail Concept: MHD and Kinetic Studies
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DOI：
10.2514/6.2003-5225
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
G. Khazanov;P. Delamere;K. Kabin;T. Linde;E. Krivorutsky
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文献类型：
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作者：
G. Khazanov;P. Delamere;K. Kabin;T. Linde;E. Krivorutsky
最初由Winglee等人[2000年]提出的微型磁层等离子体推进（M2 P2）预测，15公里的磁泡间隔距离（或20公里的横截面尺寸）将提供足够的太阳风动量转移，使航天器在大约三个月的加速期后加速到前所未有的50-80公里/秒的速度。这样的速度将使旅行出太阳系的时间约为七年，几乎是一个数量级的改进，目前的化学推进系统。然而，对于Winglee等人[2000]的模拟参数，M2 P2与太阳风相互作用的流体模型是无效的。在通常应用于行星磁层的MHD流体模型中，假设特征尺度尺寸远大于太阳风的拉莫尔半径和离子趋肤深度。在M2 P2的情况下，磁泡的尺寸实际上小于或相当于这些特征参数的尺度。因此，必须使用动力学方法，解决小规模的物理机制。我们采用了两个组件的方法来确定的动量转移到等离子帆的初步估计。第一部分是磁泡小尺度膨胀相的自洽MHD模拟。流体处理是有效的，大约5公里的源和稳态MHD解决方案在5公里的边界，然后被用作混合模拟的初始条件。混合模拟表明，动量转移到最里面的区域的等离子体帆是可以忽略不计的。
The Mini-Magnetospheric Plasma Propulsion (M2P2), originally proposed by Winglee et al. [2000] predicts that a 15-km standoff distance (or 20-km cross-sectional dimension) of the magnetic bubble will provide for sufficient momentum transfer from the solar wind to accelerate a spacecraft to the unprecedented speeds of 50-80 km/s after an acceleration period of about three months. Such velocities will enable travel out of the solar system in period of about seven years-almost an order of magnitude improvement over present chemical based propulsion systems. However, for the parameters of the simulation of Winglee et al. [2000], a fluid model for the interaction of M2P2 with the solar wind is not valid. It is assumed in the MHD fluid model, normally applied to planetary magnetospheres, that the characteristic scale-size is much greater than the Larmor radius and ion skin depth of the solar wind. In the case of M2P2, the size of the magnetic bubble is actually less than or, comparable to, the scale of these characteristic parameters. Therefore, a kinetic approach, which addresses the small-scale physical mechanisms, must be used. We have adopted a two-component approach to determining a preliminary estimate of the momentum transfer to the plasma sail. The first component is a self-consistent MHD simulation of the small-scale expansion phase of the magnetic bubble. The fluid treatment is valid to roughly 5 km from the source and the steady-state MHD solution at the 5 km boundary was then used as initial conditions for the hybrid simulation. The hybrid simulations showed that the momentum transfer to the innermost regions of the plasma sail is negligible.