Experimental study on the heating of silicate aggregates and the formation of chondrules by nebula shock

星云激波加热硅酸盐聚集体及球粒形成的实验研究

• 批准号: 13440156
• 负责人: ARAKAWA Masahiko
• 金额: $ 9.47万
• 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: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13440156/
• 关键词: Chondrule; Shock wave; Solar nebula; Chondrites; Silicate aggregates; Flash heat; High speed camera; Shock tube; コンドライト阻石; マッハ数; 高速気流; 液滴分裂; 摩擦加熱; 高速度デジタルビデオカメラ

We have developed a new instrument to generate a strong shock wave with a large Mach number in gas. This instrument was consisted of a two-stage light gas gun and a small high-pressure vessel set in a sample chamber evacuated in a vacuum. Collisions among nebula gas and the dust-gas interaction in a generated shock wave were simulated with this instrument. A nylon projectile with the size of 1.6mm was launched into the high-pressure vessel filled with 1 bar air and this projectile generates a strong shock wave after it penetrates into the air. We have observed a bow shock with the Mach number larger than 9 around the projectile by using a high-speed photography, but we didn't observe any emission from the shock compressed gas and the surface of the projectile heated by gas drag. The projectile was observed to be intact without any disruption and melting after the penetration into the gas.We have also studied a disruption experiment of a water droplet by high velocity gas flow. This study simulates a completely molten silicate droplets caused by nebula shock, which are compressed or sheared by gas drag. The disrupted silicate melts could be related to the origin of chondrules based on the evidence such as the size distribution and the characteristics of the shape. We have conducted this experiment with a water droplet whose size is 0.3 to 5mm at the condition with the Mach number from 1.01-1.12 by using a shock tube in air. The disruption was observed by a high-speed digital video and the size distribution of the disrupted droplets was analyzed. Our result shows that the disrupted droplets have an exponential relationship for the cumulative mass distribution and the slope of this exponential relation is found to depend on a Weber number (4-400)

我们研制了一种在气体中产生大马赫数强激波的新仪器。该仪器由一个两级轻气枪和一个小型高压容器组成，该容器设置在真空中抽真空的样品室中。用该仪器模拟了星云气体之间的碰撞和产生激波的尘埃-气体相互作用。将尺寸为1.6mm的尼龙弹丸发射到充满1bar空气的高压容器中，弹丸穿透空气后产生强烈的冲击波。我们用高速摄影观察了弹丸周围马赫数大于9的弓形激波，但我们没有观察到激波压缩气体的发射和弹丸表面被气体阻力加热。弹丸被观察到完好无损，没有任何破坏和熔化后，穿透气体。我们还研究了高速气流对水滴的破坏实验。本研究模拟了由星云激波引起的完全熔融的硅酸盐液滴，这些液滴被气体阻力压缩或剪切。根据球粒的大小分布和形状特征等证据，断裂的硅酸盐熔体可能与球粒的起源有关。在马赫数为1.01-1.12的条件下，我们利用空气中的激波管对0.3 - 5mm大小的水滴进行了实验。通过高速数字视频观察了破裂过程，并分析了破裂液滴的尺寸分布。我们的结果表明，被破坏的液滴具有累积质量分布的指数关系，并且发现该指数关系的斜率依赖于韦伯数（4-400）。

项目成果

Kadono, T.: "Crack Propagation in Thin Glass Plate Caused by High Velocity Impact"Phys. Rev. E. (in press). (2002)

Kadono, T.：“高速冲击引起的薄玻璃板裂纹扩展”Phys。

Nakano, H.: "Alteration of interstellar organic materials in meteorites' parent bodies : a novel route for diamond formation"Proc. The Japan academy. 78-9. 277-281 (2002)

Nakano, H.：“陨石母体中星际有机物质的改变：钻石形成的新途径”Proc。

Arakawa, M.: "Impact processes of ice in the solar system"in High-Pressure Shock Compression of Solids V edited by L.Davison, Y.Horie and T.Sekine (Springer-Verlag, New York)). 199-231 (2002)

Arakawa, M.：《固体高压冲击压缩 V》中的“太阳系中冰的冲击过程”，由 L.Davison、Y.Horie 和 T.Sekine 编辑（Springer-Verlag，纽约）。

Kouchi, A.: "Crystallization Heat of Impure Amorphous H2O Ice"Geophys. Res. Lett.. 28. 827-830 (2001)

Kouchi, A.：“不纯非晶 H2O 冰的结晶热”地球物理学。

Arakawa, M.: "Observation of crack propagation in water ice with fluid inclusion"Canadian Journal of Physics. 81. 159-166 (2003)

Arakawa, M.：“观察带有流体包裹体的水冰中的裂纹扩展”加拿大物理学杂志。