Inductive pulsed plasma thruster model with time-evolution of energy and state properties
Inductive pulsed plasma thruster model with time-evolution of energy and state properties
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DOI：
10.1088/0022-3727/46/47/475201
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发表时间：
2013-10
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影响因子：
--
通讯作者：
K. Polzin
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文献类型：
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作者：
K. Polzin
提出了脉冲感应等离子体加速模型，该模型由一组与一维 (1D) 运动方程和控制能量分配方程耦合的电路方程组成。后两个方程是通过将等离子体电流片视为有限体积的单个元素并对该体积上的控制方程进行积分而获得的。必要时，积分项可替换为物理等效近似值，这些近似值是通过控制方程组其他部分的解计算得出的。该模型通过允许温度的时间演化与进入等离子体的时变能量通量一致，改进了之前的一维性能模型。等离子体状态特性也可以更真实地建模并及时演化，从而可以根据可能被选作推进剂的不同气体来定制模型。给出了氩推进剂的计算结果以证明该模型的有效性。该模型产生的结果是，在给定的电动标度项（称为动态阻抗参数）下，效率达到最大。不同能量汇的缩放作为动态阻抗参数的函数提供了对这些类型的加速器中的全局能量分配的洞察。当前模型的结果与之前的版本不同，之前的版本选择温度作为输入，而不考虑将气体加热到该温度所需的能量。该模型在定性和定量方面预测了比冲值，该值与两个单独的感应脉冲等离子体推进器测量的值相比更为有利。在有数据可用的情况下，效率被低估，但数据和模拟的趋势遵循相似的轨迹，随着动态阻抗参数的增加，这些轨迹似乎正在向预测的峰值效率收敛。
A model for pulsed inductive plasma acceleration is presented that consists of a set of circuit equations coupled to both a one-dimensional (1D) equation of motion and an equation governing the partitioning of energy. The latter two equations are obtained for the plasma current sheet by treating it as a single element of finite volume and integrating the governing equations over that volume. The integrated terms are replaced where necessary by physically equivalent approximations that are calculated through the solution of other parts of the governing equation set. The model improves upon previous 1D performance models by permitting the time-evolution of the temperature consistent with the time-varying energy flux into the plasma. The plasma state properties are also more realistically modelled and evolved in time, allowing for the tailoring of the model to different gases that may be chosen as propellants. Computational results for argon propellant are presented to demonstrate the efficacy of the model. The model produces a result where efficiency is maximized at a given value of the electrodynamic scaling term known as the dynamic impedance parameter. The scaling of different energy sinks as a function of the dynamic impedance parameter provides insight into the global energy partitioning in these types of accelerators. Results from the present model deviate from the previous version where temperature is selected as an input without regard for the energy that would be deposited to heat the gas to that temperature. Qualitatively and quantitatively, the model predicts specific impulse values that compare favourably with those measured for two separate inductive pulsed plasma thrusters. Efficiency is underpredicted in the regime where data are available, but the trends in the data and simulations follow similar trajectories that appear to be converging towards a predicted peak efficiency as the dynamic impedance parameter is increased.