Study of snow avalanches, ice-blast and collision of icy planetary bodies by high-speed impact and shock-wave experiments of ice

通过冰的高速冲击和冲击波实验研究雪崩、冰爆和冰行星体碰撞

• 批准号: 07459002
• 负责人: MAENO Norikazu
• 金额: $ 4.1万
• 依托单位: HOKKAIDO UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07459002/
• 关键词: ice; high-speed collision; shock wave; snow avalanche; ice blast; icy planetary body

Detailed processes of ice impact and its relation to shock waves have not been clarified mainly because of various experimental difficulties. However the processess are the most important to understand the mechanism of natural high-speed snow avalanches, practical ice blast techniques, and various planetary collisions of icy bodies. This study was aimed at obtaining the fundamental and common information related to the above-mentioned phenomena by making three different experiments of ice.High-Speed impact experiments were made in a large cold room maintained at -15 degree C.A light gas gun was used to impact ice projentile on ice or snow plates. The impact speed was from 50 to 700 m/s. The experiments at lower speeds were made by dropping ice or snow blocks from a 15-m high tower. Shock tubes were also used to observe the interaction between a shock wave and fine ice particles. In all the three experiments the behavior of ice and snow was observed by high-speed video and image-converter cameras using Schlieren and shadow photography. The analyzes of the obtained datagave many important results such as crack development, ice ejection velocities, etc., the physical implications of which were discussed in each natural and planetary phenomenon.

尚未阐明冰撞击的详细过程及其与冲击波的关系，主要是因为各种实验困难。但是，该过程是了解天然高速雪雪崩的机制，实用的冰爆技术以及冰冷体的各种行星碰撞的机理。这项研究的目的是通过进行三种不同的冰实验获得与上述现象有关的基本和常见信息。在维持-15度的大型冷房间中进行了高速冲击实验。使用-15度C.轻型燃气枪用于撞击冰或雪板上的冰造型。冲击速度为50至700 m/s。通过从15米高塔下掉冰块或雪地块来进行较低速度的实验。电击管还用于观察冲击波和细冰颗粒之间的相互作用。在这三个实验中，使用Schlieren和Shadow Photography通过高速视频和图像传感器摄像机观察到冰和雪的行为。对获得的数据的分析许多重要结果，例如裂纹发育，冰射速等，在每个自然和行星现象中都讨论了物理含义。

项目成果

Nishimura, K.: "Measurements and numerical simulationsof snow particle saltation" Annals of Glaciology. in press. (1997)

Nishimura, K.：“雪粒跃移的测量和数值模拟”冰川学年鉴。

Sugi, N.: "In-situ mass spectrometric observationof impact vaporization of water-ice at low temperatures" Geophys.Res Let.in press. (1997)

Sugi, N.：“低温下水冰冲击汽化的原位质谱观察”Geophys.Res Let.in press。

Arakawa, M.: "Mechanical strength of polycrystallineice under uniaxial compression" Cold Regions Sci.Tech.in press. (1997)

Arakawa, M.：“单轴压缩下多晶冰的机械强度”冷区科学技术出版社。

Keller, S.: "Measurements of the velocity distribution in ping-pong ball avalanches." Annals of Glaciology. (in press). (1997)

Keller, S.：“乒乓球雪崩速度分布的测量。”

Arakawa, M.: "Mechanical strength of polycrystalline ice under uniaxial compression." Cold Regions Sci.Tech.(in ptess). (1997)

Arakawa, M.：“单轴压缩下多晶冰的机械强度。”