[M-IS22] 地球流体力学：地球惑星現象への分野横断的アプローチ

[MIS22-05] 内部発熱対流におけるセルサイズのRa数依存性に関する現象論モデルについて

*熊谷 一郎¹、阿部 竜太²、田坂 裕司²、Anne Davaille³、村井 祐一²、柳澤 孝寿⁴ (1.明星大学　理工学部、2.北海道大学 工学研究院、3.FAST, CNRS, パリ南大学、4.海洋研究開発機構　地球深部ダイナミクス研究分野)

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.