Critical Velocity and Turbulence in Superfluid Liquid Helium

超流液氦中的临界速度和湍流

• 批准号: 60540225
• 负责人: YAMADA Kazuo
• 金额: $ 1.28万
• 依托单位: Nagoya 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: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1987
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60540225/
• 关键词: Superfluid; Liquid ^4He and ^3He; Critical velocity; Vortex line; Superfluid turbulence; Couette-Jaylar flow; Covette-Taylar流; 液体ヘリウム; 渦糸; Couette-Taylar流; ボーズ液体液体ヘリウム【^3He】

(1) Stochastic theory of vortex tangle in superfluid turbulence was developed.The extended Vinen equation for the vortex line length density and two fluid hydrodynamical equation including the generalized form of mutual friction force were obtained. Further the existence of eddy viscosity was predicted.(2) It was confirmed that some particular solutions in non-steady and non-uniform cases of Vinen equation correspond well to various turbulent patterns observed in capillary flows.(3) It was predicted that the appearance of eddy viscosity gives the interpretation of excess pressure difference observed in capillary flows as well as the interaction between boundary and vortex lines.(4) Linear instability in Couette-Taylar flow was examined on the basis of generalized two fluid hydrodynamical equations. It was shown that the result did not qualitatively agree to both magnitude and temperature dependence of the observed critical Taylar number. This result suggests that the eddy viscosity should be taken into account.(5) The possibility occuring of new condensed phase of superfluid ^3He was examined when it is put into the finite region. It was shown from variational calculation that the stabilization of B-phase is realized in place of A-phase due to size effect, and the planar state may appear under some boundary condition on the wall.(6) Superfluidity of ^4He film absorbed in the restricted geometry was intestigated. It was shown that in ^4He within zeolite the disappearance of Bose statistics leads to the decrease of transition temperature, and in^4He in Vycor glass and the sintered metallic fine particles interaction between vortex pairs becomes one dimensional and as a result agrees to the observed results qualitatively.

(1)发展了超流湍流中涡旋缠结的随机理论，得到了涡线长度密度的扩展Vinen方程和包含互摩擦力广义形式的两流体流体动力学方程。进一步预测了涡动粘性的存在。(2)结果表明，在非定常和非均匀情况下，Vinen方程的某些特解与毛细流动中观察到的各种湍流模式有很好的对应关系。(3)据预测，涡粘性的出现给出了解释的超压差观察到的毛细管流动以及边界和涡线之间的相互作用。(4)本文从广义双流体动力学方程出发，研究了Couette-Taylar流动中的线性不稳定性。结果表明，该结果并不定性地同意所观察到的临界泰勒数的幅度和温度依赖性。这一结果表明，涡粘性应考虑。(5)考察了超流^3He在有限区域内出现新凝聚相的可能性。变分计算表明，由于尺寸效应，B相代替A相稳定化，在壁面上满足一定的边界条件时，可能出现平面状态。(6)研究了^4He薄膜在受限几何条件下的超流性。结果表明，在沸石中的^4He中，玻色统计的消失导致相变温度的降低，而在Vycor玻璃和烧结金属细颗粒中的^4He中，涡旋对之间的相互作用变为一维，这与观测结果定性一致。

项目成果

S. Kashiwamura, K. Miyake, K. Yamada and J. Yamauchi: "Stability of Rotating Couette Flow of Superfluid ^4He." Proc. 18th Int. Conf. on Low Temp. Phys. Kyoto, Japanese J. Appl. Phys.26. Suppl. 26-3. 97 (1987)

S. Kashiwamura、K. Miyake、K. Yamada 和 J. Yamauchi：“超流体 ^4He 旋转库埃特流的稳定性”。

蓑口友紀: Prog.Theor.Phys.78. 552 (1987)

Yuki Minoguchi：Prog.Theor.Phys.78 (1987)。

高木文夫: Proc.18th Int.Conf.on Low Temp.Phys.Kyoto Japanese Jour.Appl.Phys.Vol.26.Suppl.26-3. 139 (1987)

Fumio Takagi：Proc.18th Int.Conf.on Low Temp.Phys.Kyoto Japanese Jour.Appl.Phys.Vol.26.Suppl.26-3 (1987)。

高木文夫: Prog.Theor.Phys.78. 562 (1987)

高木文雄：Prog.Theor.Phys.78 (1987)。

高木文夫: Prog.Theor.Phys.Letter.79. (1988)

高木文雄：Prog.Theor.Phys.Letter.79 (1988)。