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

在格栅水池和风浪水池中进行了海水对CO2气-水界面传输影响的实验研究。结果表明，含盐量为3.5wt%的海水、天然海水和人工海水沃茨对CO2在非破裂气-水界面上的传输速度的衰减为纯水和自来水沃茨的50%。这种减少不是由天然海水特有的表面污染物引起的，而是由所有海水和淡水沃茨中常见的非常微小的表面活性杂质引起的。表面活性杂质降低了CO2的分子扩散率在共同的接口，7%的分子扩散率在真正干净的界面。海水和淡水沃茨之间的分子扩散系数差异很小，但电解质的作用很弱，而CO2的迁移速度却相差很大。当界面破裂时，海水与淡水的迁移速度之比从0.50增加到0.97。特别是当界面破碎严重时，传递速度之间的差值变得很小。这是由于新鲜的体相流体取代了界面，削弱了表面活性杂质对传质的影响。

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.