Three-dimensional Dynamics of Quan

拳的三维动力学

• 批准号: 06640497
• 负责人: TSUBOTA Makoto
• 金额: $ 1.34万
• 依托单位: Tohoku University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06640497/
• 关键词: Superfluid; Quantized Vortex; Computational Physics; Low Temperature; Pinning; Vortex Array; ピン止め; ソリトン; 超流動ヘリウム; 熱カウンター流; 再結合

We have studied three-dimensional dynamics of quantized vortices in superfluid helium. First, we investigated vortex pinning that simulates the roughness of the channel surface. After the condition that vortices are attracted to a pinning site is discussed, the capacity of a pinning site is studied ; a pinning site can keep only less than five vortices. The obtained critical depinning velocities are compared with some experimental results for thermal counterflow. Secondly, vortex dynamics in rotating superfluid is studied. A rotating superfluid is known to form an array of vortices which are paralled to the rotational axis, yet very little is understood about the dynamics. Thus we made two-dimensional analysis, studying the formation of vortex arrays and its decay in spin-down processes which are typical of dynamical problems. However, only two-dimensional analysis is insufficient to understand the real system. Hence three-dimensional analysis was made. The numerical calculation for a superfluid in a rotating spherical vessel found that the angular velocity of the vessel necessary for stretching a small vortex nucleated at the boundary is larger than the observed critical angular velocity for one-vortex nucleation ; not a nucleated vortex but some remnant vortices may play an important role in a real system. The array decay through the spin-down processes is studied in detail. The propagation of a soliton along a vortex is investigated.

我们研究了超流体氦气中量化涡旋的三维动力学。首先，我们研究了模拟通道表面粗糙度的涡旋固定。在讨论了将涡流吸引到固定位点的情况下，研究了固定位点的容量。固定网站只能保持少于五个涡流。将获得的临界静态速度与热逆流的一些实验结果进行了比较。其次，研究了旋转超流体中的涡流动力学。已知旋转的超流体形成与旋转轴相位的涡流阵列，但对动力学的了解很少。因此，我们进行了二维分析，研究了涡流阵列的形成及其在旋转过程中的衰减，这是典型的动态问题。但是，只有二维分析不足以理解实际系统。因此进行了三维分析。旋转球形容器中超氟的数值计算发现，在边界处拉伸小涡流所需的血管速度比观察到的单涡质成核的关键角速度要大；不是成核的涡旋，但某些残留的涡旋可能在实际系统中起重要作用。详细研究了通过旋转过程的阵列衰减。研究了沿着涡旋的孤子的传播。

项目成果

M.Tsubota and H.Yoneda: "Dynamics of Quantized Vortices under an Applied Flow in Superfluid Helium" Proceedings of the ASME-JSME Thermal Engineering Joint Conference. 483-490 (1995)

M.Tsubota 和 H.Yoneda：“超流氦应用流动下的量子化涡流动力学”ASME-JSME 热工联合会议论文集。

M. Tsubota and S. Maekawa: "Collision of Quantized Vortices in Superfluid Helium and Effect of Applied Superflow" JSME International Journal Series B. 38. 295-299 (1995)

M. Tsubota 和 S. Maekawa：“超流氦中量子化涡流的碰撞和应用超流的影响” JSME 国际期刊系列 B. 38. 295-299 (1995)

M.Tsubota and S.Maekawa: "Dynamics of Two Quantized Vortices on a Pinning Site" Physica B. 194-196. 721-722 (1994)

M.Tsubota 和 S.Maekawa：“固定位点上两个量子化涡流的动力学”Physica B. 194-196。

F. Takemura, Y. Matsumoto, M. Tsubota and Y. Tomita: "Effects of the Internal Phenomena on Bubble Motion Liquid Nitrogen" Cavitation and Multiphase Flow-1995-. 187-192 (1995)

F. Takemura、Y. Matsumoto、M. Tsubota 和 Y. Tomita：“内部现象对气泡运动液氮的影响”空化和多相流-1995-。

米陀英毅,坪田誠: "超流動ヘリウムにおける境界面付近の量子渦と運動と流れ場の影響" 日本機械学会論文集(B編). 61. 2365-2371 (1995)

Hideki Yoneda、Makoto Tsubota：“超流氦界面附近的量子涡流、运动和流场的影响”日本机械工程师学会汇刊 (ed. B) 61. 2365-2371 (1995)。