Study ofNon-linear Wave and Quantum Phase Transition Phenomena in Superfluid Helium Performed in Superfluid Shock Tube Facility

超流激波管装置中超流氦非线性波和量子相变现象的研究

• 批准号: 11305068
• 负责人: MURAKAMI Masahide
• 金额: $ 21.7万
• 依托单位: Institute of Engineering Mechanics, University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11305068/
• 关键词: Shock Wave; Superfluid Hilium; Lambda Phsase Transition; Superfluid Shock Tube Facility; Isentropit Process; Shock Compression; Thermal Shock Wave; Khalatnikov Theory; λ-相転移; 断熱変化; エントロピ生成; 衝撃波管; λ相転移; 固体ヘリウム; 超高レイノルズ数流れ; 圧縮衝撃波; 超臨界状態; 量子

The quality of the compression nand thermal shock waves generated in the superfluid shock tube facility was found to be satisfactorily high enough for general shock wave researches. It was found that the temperature dropped in a compression shock wave and the intensity of thermal shock waves were very strong compared with those generated by pulsed heating in HeII.The velocity of the uniform flow behind a compression shock could be calculated from the visualization image with the ultra high speed video. The Reynolds number of the flow was extremely high, as high as the order of 107. This result indicates that the facility may be an alternative to the super fluid wind tunnel.The physical state of the shock compressed state at a shock front generally obeys an isentropic process in the case when the initial state of liquid helium is far from the lambda point. It is, however, found that considerable entropy production is induced in the vicinityofthe lambda line in the case where the initial equilibrium state of liquid helium is close to the lambda point. The excess entropy production was roughly in proportion to the temperature difference from the lambda point temperature.It is found from the high speed pictures that a strong density fluctuation was induced behaind a compression shock while crossing the lambda line.Some experiments are/conducted toward the experiments for solidification of He II.

超流体激波管设施中产生的压缩和热激波的质量对于一般激波研究来说足够高。结果发现，与HeII中脉冲加热产生的相比，压缩冲击波中的温度下降和热冲击波的强度非常强。压缩冲击后的均匀流动的速度可以从可视化图像中计算出来：超高速视频。流动的雷诺数极高，高达107量级。这一结果表明该装置可能是超流体风洞的替代品。激波锋面激波压缩状态的物理状态一般服从液氦初始状态远离 lambda 点时的等熵过程。然而，人们发现，当液氦的初始平衡状态接近λ点时，在λ线附近会引起相当大的熵产生。过量熵的产生大致与与 lambda 点温度的温差成正比。从高速图像中发现，在穿过 lambda 线时，压缩激波后面会引起强烈的密度波动。一些实验是针对He II 的凝固实验。

项目成果

H.S. Yang: "Experimental Investigation of Thermal Shock Wave Induced by Gas Dynamic Shock Wave Impingement"Advances in Cryogenic Engineering. 45A. 961-968 (2000)

H.S.

Y.Ueta: "Propagation of a compression shock wave in He II induced by gasdynamic shock wave impingement onto He II free surface"Shock Waves, Proc. 23rd International Symposium on Shock Waves. (発表予定). (2002)

Y.Ueta：“He II 自由表面上的气体动力冲击波引起的压缩冲击波的传播”，《冲击波》，第 23 届国际冲击波研讨会（2002 年）。

H.Nagai: "Experimental study of thermal shock wave in superfluid shock tube facility"Shock Waves, Proc. 23rd International Symposium on Shock Waves. (発表予定). (2002)

H.Nagai：“超流体激波管设施中的热冲击波实验研究”，《冲击波》，第 23 届国际冲击波研讨会（即将发表）。

ヤンヒョンソク: "超流動ヘリウム中で衝撃波の伝播についての実験的研究"低温工学. 36-9. 534-540 (2001)

Yang Hyun-seok：“超流氦中冲击波传播的实验研究”，低温工程 36-9（2001）。

H. Nagai: "Study of two modes of shock waves and Atransition in He II induced by shock compression"Shock.Waves, Proc. 22nd International Symposium on Shock Waves. 1105-1110 (1999)

H. Nagai：“冲击压缩引起的 He II 中两种冲击波模式和转变的研究”Shock.Waves，Proc。