Fluid Mechanical Studies on the Effects of Wave-Breaking on the Mass Transfer Across the Air-Water Interface.

波浪破碎对空气-水界面传质影响的流体力学研究。

• 批准号: 07455087
• 负责人: KOMORI Satoru
• 金额: $ 4.86万
• 依托单位: KYUSHU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07455087/
• 关键词: Air-Water Interface; Turbulence Structure; Mass Transfer; Wave Breaking; 大気海洋の相互作用; 風波

The effects of sea water on the CO2 transfer across the air-water interface were experimentally investigated in both an oscillating-grid tank and a wind-wave tank. The results show that the CO2 transfer velocities across non-breaking air-water interfaces for 3.5wt% salt, natural sea and artificial sea waters are damped to 50% of those for pure and tap waters. The reduction is caused not by surface contaminants characteristic of natural sea water but by the presence of very tiny surface-active impurities common to all the sea and fresh waters. The surface-active impurities reduce the molecular diffusivity of CO2 at common interfaces to 7% of the molecular diffusivity at the really clean interface. The reduction amplifies the weak effect of electrolytes on the small difference of the molecular diffusivity between sea and fresh waters and it results in the large diffence of the CO2 transfer velocity. Further the ratio of the transfer velocity of sea water to that of fresh water increases from 0.50 to 0.97 as the interface is broken. Especially the differece between the transfer velocities becomes very samll for intensively broken interface. This is attributed to that the effect of surface-active impurites on the mass transfer is weaken by the replacement of the interface by the fresh bulk-fluid.

在振动网格槽和风浪槽中实验研究了海水对空气-水界面CO2传递的影响。结果表明，在3.5wt%盐、天然海水和人工海水中，CO2在不破坏的空气-水界面上的传递速度被阻尼到纯水和自来水的50%。这种减少不是由天然海水所特有的表面污染物引起的，而是由所有海水和淡水中共同存在的非常微小的表面活性杂质引起的。表面活性杂质使CO2在普通界面处的分子扩散率降低到真正清洁界面处分子扩散率的7%。这种还原作用放大了电解质对海水和淡水分子扩散率微小差异的微弱影响，并导致CO2传递速度的巨大差异。随着界面的破坏，海水与淡水的传递速度之比从0.50增加到0.97。特别是在界面断裂严重的情况下，传递速度差变得非常小。这是由于表面活性杂质对传质的影响被新鲜的体积流体取代而减弱。

项目成果

S.Komori: "Turbulence Structure and CO_2 Transfer at the Air-Sea Interface and Turbulent Diffusion in Thermally-Stratified Flows" 国立環境研究所地球環境センター, 51 (1996)

S.小森：“海气界面的湍流结构和CO_2传输以及热分层流中的湍流扩散”国立环境研究所全球环境中心，51（1996）

S. Komori, K. Nagata & Y. Murakami: "Heat and Mass Transfer in a Stable Thermally-Stratified Flow" Dynamics Atmos. Oceans. 23(印刷中). (1996)

S. Komori、K. Nagata 和 Y. Murakami：“稳定热分层流中的传热和传质”Dynamics Atmos（1996 年）。

S.Komori,K.Nagata & Y.Murakami: "Heat and Mass Transfer in a Stable Thermally Stratified Flow" Dynamics of Atmospheres and Oceans. 23・1. 235-245 (1996)

S.Komori、K.Nagata 和 Y.Murakami：“稳定热分层流中的传热和传质”大气和海洋动力学 23・1（1996）。