动能撞击偏转小行星的动量传递效率数值仿真研究

Numerical Simulation Study on Momentum Transfer Efficiency of Kinetic Impact Deflection of Asteroid

动能撞击是偏转潜在危险小行星的一种可行手段,动量传递效率是衡量动能撞击偏转效果的主要指标。基于美国国家航空航天局(NASA)的DART试验场景,采用自研的冲击动力学仿真软件NTS开展动能撞击偏转小行星数值仿真,分析材料拉伸强度和孔隙率对动量传递效率的影响。仿真分析发现:材料拉伸强度越高,撞击坑尺寸越小,反溅碎片总质量越小,动量传递效率越低。在孔隙材料中冲击波会快速衰减,导致动能撞击破坏区域减小,孔隙率越高,反溅碎片总质量越小,动量传递效率越低。

Kinetic impact is a feasible method to deflect potentially hazardous asteroids,and the momentum transfer efficiency is the main indicator to evaluate the deflection result.Based on the NASA DART scenario,numerical simulations of kinetic impact on asteroid for deflection were carried out by use of a homemade hydrocode NTS,for analysis of the influences of tensile strength and porosity on the momentum transfer efficiency.It is found that material with stronger tensile strength,would lead to smaller impact crater,less total ejecta mass and lower momentum transfer efficiency.The shockwave attenuating rapidly in porous material,resulting in smaller damage area,with higher porosity would lead to less total ejecta mass and lower momentum transfer efficiency.