Study on Air-Sea Gas Transfer at Natural Coast

对非破碎波表面、近岸建筑物前表面和模型海滩破碎带表面的传质系数进行了实验和理论研究。1.非破碎波浪表面的再掺气：用小型波浪水槽试验数据对中型波浪水槽试验数据进行了检验。结果表明，非破碎波表面的复氧主要是由于内摩擦引起的能量耗散，同时也是由于池壁和底部的摩擦引起的。在此基础上，本文提出了一种预测真实的海面非破碎波表面传质系数的方法。此外，还对真实的海洋进行了计算，以与Horie提出的数值进行比较。海岸建筑物前波浪表面的再曝气：利用小型波浪水槽进行了海堤前波浪表面传质系数的实验研究。装甲单位的重量的影响也进行了检查。模型海滩上碎波带的再曝气：对模型海滩上碎波带的再曝气进行了研究。注意到了海滩的坡度的影响，以及波浪尺度的影响。从检查中，它表明，传质系数与能量耗散率有很强的和独特的关系，无论底坡，破碎的类型，和波浪周期。

Experimental and theoretical research to evaluate the mass transfer coefficient at the surfaces of non-breaking waves, on the surfaces of waves in frout of coastal structures, and on the breaker zone on a model beach was performed. The following is obtained as results.1.Reaeration on the surfaces of non-breaking waves : Data from a middle-scale wave tanktests were examined with data which have been obtained using a small-scale wave tank. It was shown that the reaeration at the surfaces of non-breaking waves should be causeb by energy dissipation due to internal friction, and due to frictions at side walls and bottom of the tank. On the basis of the examination, we proposed a method to predict the mass transfer coefficient in full scale at the surfaces of non-breaking waves in the real sea. In addition, some calculations on the real seas were performed for comparison with the value proposed by Horie.2. Reaeration on the surfaces of waves in front of coastal structures : Experiments to measure the mass transfer coefficient on the surfaces of waves in frout of sea wall were performed using a small-scale wave tank. The effects of the weights of armor units were also examined.3. Reaeration on the breaker zone on a model beach : Reaeration on the breaker zone on a model beach was examined. Attention was paid to the effects of the slopes of a beach, and to the effects of the scale of waves. From the examination, it was shown that the mass transfer coefficient has a strong and unique relationship with energy dissipation rate, despite the bottom slope, the type of breaking, and the wave period.