摘要
本文用两维半MHD数值模型,模拟研究了不同间距的两扰动源所产生的激波在行星际空间黄道面内的相互碰撞过程。在内边界(18R_s),两扰动中心的间距取为24°、36°、48°、54°、72°、120°,模拟了两激波速度均为1000km/s和2000km/s两种情形。结果表明:1.速度为1000km/s的两中等激波,相距24°时,在1AU以内强烈相互作用而汇合成一新激波;相距36°时,在1AU附近发生汇合,但尚可分辨;相距48°时,在1AU以内有相互作用,但可近似认为是独立传播的;相距72°时,将独立向前传播。2.速眨为2000km/s的两强激波,相距≤48°时,将强烈汇合成一新激波;相距54°时,在1AU附近产生汇合,但尚可分辨;相距72°时,相互作用不足以汇合成新的激波;相距120°时,其传播相互独立地进行。并给出了上述情形下两激波汇合的时间和位置,详细比较了汇合激波与相同能量的单激波的等离子体特性。
The MHD 2 - D, time-dependent model is used to investigate neighboringinterplanetary shock wave interactions in the equatorial plane, with different angular separations. For tow shocks with initial velocity vs = 1000 km/s, the main results are: For the case of angular separation Δφ=24°, the two shock waves completely coalesced into a new shock within 1 AU; For the case of Δφ = 36°, the two shock waves coalesced into a new shock wave near 1AU; For the case of Δφ= 48°, the azimuthal collision of the two shocks occured, and a coalescence could partly be seen within 1 AU;For the case of Δφ = 72°, one would not almost see the collision of the two shock waves, that is their propagations are independent each other.For the two shocks with initial velocity vs = 2000 km/s, main results are: For the case of Δφ ≤48°, the two shock waves completely coalesced into a new shock within 1 AU; For the case of 54°, the two shock waves coalesced into a new shock near 1 AU; For the case of Δφ = 72°, the two shock waves collided azimuthally, but could be identified from their distributions; For the case of Δφ = 120°, the two shock waves propagated independently.
出处
《空间科学学报》
CAS
CSCD
北大核心
1993年第2期90-97,共8页
Chinese Journal of Space Science
基金
国家自然科学基金
关键词
行星际激波
数值模拟
激波汇合
Interplanetary shock wave, MHD simulation, Coalescence of two shocks
