COMPUTER SIMULATION OF ION-ACOUSTIC SHOCKS. THE DIAPHRAGM PROBLEM.
COMPUTER SIMULATION OF ION-ACOUSTIC SHOCKS. THE DIAPHRAGM PROBLEM.
复制标题
离子声冲击的计算机模拟。
DOI：
10.1063/1.1693704
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发表时间：
1971
影响因子：
4.6
通讯作者：
R. Mason
中科院分区：
文献类型：
--
作者：
R. Mason
用混合粒子单元计算机模拟方案研究了隔膜问题中的离子声冲击，该方案将离子视为粒子，将电子视为等温流体。给出了从初始密度跳跃1.2≤R = nI/nII≤15，初始温度1≤θ = Te/TiII≤60，到ωpiIIt≤60的时间的流动的相空间图和密度分布，其中II表示原始的低密度条件。当R = 1.2时，所得结果与以前的精确线性化解非常接近雅阁.流动包含几乎反对称的压缩和膨胀区域，在θ = 30处嵌入小波，当θ≤5时朗道衰减。新的非线性特征包括：（a）当R = 1.2→15，θ = 30时，激波马赫数从1.00增加到1.48;（= 1.20）;（B）在θ = 30的锋前以1.60到1.80倍的锋速行进的前驱体，对于1.6≤R≤15，（c）由于从高度增加的朗道阻尼，在大R处锋后的子波被洗出。
Ion‐acoustic shocks in the diaphragm problem are examined with a hybrid particle‐in‐cell computer simulation scheme that treats ions as particles and electrons as an isothermal fluid. Phase space plots and density profiles are given for flows from initial density jumps 1.2≤R = nI/nII≤15, with initial temperatures 1≤θ = Te/TiII≤60 and for times out to ωpiIIt≤60, where II denotes the original low‐density conditions. For R = 1.2, results are in close accord with previous exact linearized solutions. The flows contain nearly antisymmetric compression and expansion regions, with embedded wavelets at θ = 30, Landau damped away for θ≤5. New nonlinear features include (a) an increase of the shock Mach number from 1.00 to 1.48, as R = 1.2→15 at θ = 30, and a constant Mach number ( = 1.20) for R = 3 and variable θ; (b) a precursor ahead of the θ = 30 fron traveling at 1.60 to 1.80 times the front speed for 1.6≤R≤15, (c) wash‐out of the wavelets behind the front at large R due to increased Landau damping from heighte...