Experimental Study on the Transition to Superfluid Turbulent Flow

超流体湍流过渡的实验研究

• 批准号: 01460085
• 负责人: MURAKAMI Masahide
• 金额: $ 4.16万
• 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 General Scientific Research (B)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01460085/
• 关键词: Superfluid; Liquid Helium; Superfluid Turbulent Flow; Thermal Counterflow; 2nd Sound Helmholtz Oscillation; Thermal Shock Wave; Quantized Virtices; Fountain Pump; 熱衡撃波; 超流動崩壊; HeII

Several experimental approaches are attempted for the study of the transition of superfluid flow to superfluid tubulent flow, and the following results are obtained.i) Measurement of the thermal counterflow jet by applying a flow visualization tecnique and with a laser Doppler velocimeter : In particular, thermally excited 2nd sound Helmholtz oscillation is investigated to elusidate the condition for the appearance of the oscillation phenomena and to analyze the modulation to the oscillation as a result of the transition to the superfluid turbulent flow. The experimental results are found to agree with the prediction by the linear stability analysis. This fact seems to indicate that the Gorter-Mellink mutual friction term is a satisfactory approximation for the cases of small and slow disturbances.ii) Numerical simulation for the two-fluid equations (analysis of a thermal shock wave) : The effects of the introduction of the Gorter-Mellink term and of the equation of vortex density evol … More ution to the governing equations, both of which are phenomenological description for the interaction of the tangled vortices with a shock wave, are compared to see the wave form modification caused by the mutual friction. The comparison suggests that the latter treatment provides far better result but both approaches are still insufficient for a quantitative estimation.iii) Measurement of the flow through a fountain effect pump element in the superfluid turbulent flow (non-linear) region : It is indicated that the interior structure of an element should be taken into account to describe flow phenomena. A computer program on the basis of the flow model taking account of the interior structure is completed to predict the pump performance and the maximum flow rate.iv) Application of the laser hologram interferometry to superfluid measurement : The construction of the experimental apparatus including a cryostat with optical windows is nearly completed, and a preliminary experiment is successfully made. Experiment of a thermal shock wave in He II will be soon started to study the generation of tangled vortices behind a strong thermal shock wave and thus the transition of the He II field to the superfluid turbulent state. An Au-Sn superconducting thin film temperature detector for the thermal shock wave detection is manufactured and tested. Less

尝试进行了几项实验，以使超流动管流的过渡，并获得以下结果E.i），，热激发的第二个helmholtz震惊偶然融为一体。 。通过线性稳定性分析对Gorter-Mellink互助术语的预测为MALL和缓慢干扰的ASA STHE案例。 Gorter-Mellink项和方程密度Evol的影响…更多地利用了治理方程式的现象学描述，用于纠结涡流与比较引起的冲击波波形修饰的相互作用，这表明Thetter Tress Metter提供了更好的结果。对于定量估计的不足。预测泵的性能和最大流量。IV）几乎已经完成了带有光窗的低温恒温器，很快就会在天体热冲击波后面产生缠结的杂物热冲击检测的膜温度进行了人造和测试较少

项目成果

M.MURAKAMI: "Numerical Analysis of Propagation of Thermal Shock Wave Interacting with Tangled Vortices in He II." Proc.ICEC13. 340-344 (1990)

M.MURAKAMI：“热冲击波与 He II 中缠结涡旋相互作用的传播的数值分析”。

M. MURAKAMI,: "Space Cryogenics, State-of-the-Art and the Prospect" Japanese J. Cryo. Eng.25-6. 373-382 (1990)

M. MURAKAMI，：“太空低温学、最新技术和前景”日本 J. Cryo。

岩下 健: "二流体方程式の直接数値解析による熱衡撃波のシミュレ-ション" 低温工学. 25ー4. 244-249 (1990)

Ken Iwashita：“通过二流体方程的直接数值分析模拟热致波”，《低温工程》25-4（1990）。

T.HANYU: "NonーIdeal Flow through Porous Element in Fountain Pump" Proc.13th Int.Cryogenic Engineering Conf.(ICEC13). 350-354 (1990)

T.HANYU：“喷泉泵中多孔元件的非理想流动”Proc.13th Int.Cryogenic Engineering Conf.(ICEC13) 350-354 (1990)。

M.MURAKAMI: "He II Technology Development in Japan" Advanced Cryogenic Engineering. 35A. 45-54 (1990)

M.MURAKAMI：“日本He II技术发展”高级低温工程。