日本地球惑星科学連合2023年大会

講演情報

[J] オンラインポスター発表

セッション記号 M (領域外・複数領域) » M-IS ジョイント

[M-IS12] 地球流体力学:地球惑星現象への分野横断的アプローチ

2023年5月24日(水) 09:00 〜 10:30 オンラインポスターZoom会場 (4) (オンラインポスター)

コンビーナ:伊賀 啓太(東京大学大気海洋研究所)、吉田 茂生(九州大学大学院理学研究院地球惑星科学部門)、柳澤 孝寿(国立研究開発法人海洋研究開発機構 海域地震火山部門)、相木 秀則(名古屋大学)

現地ポスター発表開催日時 (2023/5/23 17:15-18:45)

09:00 〜 10:30

[MIS12-P02] 狭く閉じられた空間での熱対流

*柳澤 孝寿1,3亀山 真典2,1、高野 奏汰3能登 大輔4田坂 裕司3,1宮腰 剛広1 (1.海洋研究開発機構、2.愛媛大学地球深部ダイナミクス研究センター、3.北海道大学大学院工学研究院、4.ペンシルバニア大学)

キーワード:対流、狭い隙間、振動、数値計算

We investigated convection patterns in three-dimensional rectangular geometries by numerical simulations. The aspect ratios of both x and y horizontal directions to that of vertical direction z are the parameters to characterize the geometry. Convection is driven by the fixed temperature difference between the top and bottom boundaries, and all sidewalls are insulating. When the aspect ratio in y direction (Ly) is small, it corresponds to a model of water or magma circulation in a vertical gap. When that of x (Lx) is also small, it is a model of vertically elongated pipe. We treated Boussinesq fluid by our numerical code originally developed for mantle convection simulations. We check Ly dependence of the critical Rayleigh number (Ra) for the onset of convection. The critical value increases for smaller Ly, and approaches to that of Hele-Shaw cell. With the increase of Ra from the critical value, the horizontal scale of convection roll gets shorter, that is, the wave number of the pattern increases. On the transition, we observed emergence of oscillatory small circulations at four corners of the x-z plane. These oscillatory corner circulations emerges however large Lx is, and then the enclosed volume is divided into central steady flow region and time-dependent flow regions near the sidewalls. We investigated the feature of these oscillatory corner circulations.