Japan Geoscience Union Meeting 2015

Presentation information

Oral

Symbol M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS22] Geophysical fluid dynamics-Transfield approach to geoscience

Wed. May 27, 2015 9:00 AM - 10:45 AM 106 (1F)

Convener:*Keita Iga(Atmosphere and Ocean Research Institute, The University of Tokyo), Kensuke Nakajima(Department of Earth and Planetary Sciences,Flculty of Sciences,Kyushu University), Shigeo Yoshida(Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University), Takatoshi Yanagisawa(Institute for Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology), Hidenori Aiki(Japan Agency for Marine-Earth Science and Technology), Chair:Shigeo Yoshida(Department of Earth and Planetary Sciences, Faculty of Sciences, Kyushu University)

10:00 AM - 10:15 AM

[MIS22-05] A phenomenological model for convective cell size in a fluid layer with internal heat generation at low Rayleigh numbers

*Ichiro KUMAGAI1, Ryuta ABE2, Yuji TASAKA2, Anne Davaille3, Yuichi MURAI2, Takatoshi YANAGISAWA4 (1.School of Science and Engineering, Meisei University, 2.Faculty of Engineering, Hokkaido University, 3.Laboratoire FAST, CNRS, Universite Pairs-Sud, 4.Department of Deep Earth Structure and Dynamics Research, JAMSTEC)

The convective behavior of a fluid layer with internal heat generation at low Rayleigh number (6 ≤ RaI/RaIc ≤ 12) was experimentally investigated. The horizontal fluid layer of 0.5 wt% KCl water solution was internally heated by Joule heating using the electric current. We quantitatively measured 2-D temperature and velocity fields by seeding the micro-encapsulated thermo-chromic liquid crystals in the fluid layer. We experimentally obtained the fluid dynamic scaling on non-dimensional temperature and the maximum downwelling velocity as a function of the Rayleigh number, and also refined the experimental data obtained by the previous studies. The scaling relations were combined with a phenomenological model based on the stability of the top thermal boundary layer. This phenomenological model consistently explained the increase in convective wavelength with increasing the Rayleigh number.