雄胜高温岩体地热开发的数值计算进展

主要介绍日本电力中央研究所为秋田县雄胜高温岩体地热开发试验项目——近年开发的热-水流动藕合数值计算源程序GEOTH3D的原理、特点、应用现状和尚待改善的一些问题，并结合国际上其他相关软件的进展情况，对下一步可能的工作倾向进行了探讨。     

Quasi‐static and chaotic characteristics of the natural convection field between concentric vertical annuli

In this study unsteady and chaotic characteristics of thermal convection fields between concentric annuli were experimentally examined, and they were compared with those reported in a vertical slot. The inner cylinder was heated by an embedded heater and the outer one was cooled by temperature‐controlled cold water, and 84 wt% glycerol‐water solution was used for the present test liquid. The main results are as follows: (1) The region where the characteristic frequency of temperature fluctuation is detected is located in the upper portion of the region where the secondary cells exist. (2) The time scale of the temperature change at which the autocorrelation coefficient becomes 1/e is relatively small in the secondary‐cell region, and this corresponds to the result of the natural convection field in a vertical slot. (3) The significant chaotic characteristics of temperature fluctuation are observed in almost the same region where the characteristic frequency of temperature fluctuation is detected, and this also corresponds to the results on the vertical slot. © 2002 Wiley Periodicals, Inc. Heat Trans Asian Res, 31(6): 486–497, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.10048     

Internal gravity wave resonance of thermal convection fields in a square cavity with heat‐flux vibration

In this paper, the thermal convection field and its resonance phenomena in a square cavity with sinusoidal heat‐flux vibration were numerically investigated. As the angular velocity ω is changed, the thermal convection field at Pr = 0.71,Ra = 10⁶ is found to be classified into 5 regions. In particular, the field has the local maximum relative amplitude of midplane Nusselt's number at ω_c = 350, which corresponds to the angular velocity of internal gravity wave ω_r estimated by a theoretical equation proposed by Thorpe. This shows that the local enhancement is induced by internal gravity wave resonance. Such correspondence is observed for Ra ≥ 10⁵,Ra ≥ 10⁶ for Pr = 0.71, 7.1, respectively. For these ranges of Ra we propose a correlation equation, a function of Pr and Gr only, to estimate the resonant angular velocity. © 2006 Wiley Periodicals, Inc. Heat Trans Asian Res, 35(5): 309–322, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20122