Studies on elucidation of the air-water gas transfer mechanism on the surface of breakers and the modeling of it

破碎机表面空气-水气体传递机制的阐明及其建模研究

基本信息

批准号：
10450185
负责人：
KAKUNO Shohachi
金额：
$ 7.55万
依托单位：
Osaka City University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10450185/
关键词：
bubble gas transfer breaker global warming PTV wind waves turbulence by oscillating grid microelectrode 再曝気

项目摘要

・By visualizing breaker image taken by a special video camera, the relation between bubble characteristics and wave characteristic in the breaker zone was analyzed.・The model formula of gas transfer velocity taking the effect of the entrained bubble in the breaker zone was proposed.・An image analysis technology with high-accuracy for measurement of the flow field in the breaker zone was developed.・Applying the laser induced fluorescence, the visualization of the entrainemnet process of CO_2 gas into the water-phase was succeeded.・It was found that the penetration depth of entrained bubbles of the plunging breakers is deeper than that of the spilling breakers.・It was found that the swell in the wind-waves promotes the gas transfer and that the effect of it becomes big as the wave period becomes shorter.・Gas transfer velocity at the water surface under the condition of the vibrating grating turbulent flow field was evaluated. The velocity was found to be controlled by the Large Eddy Model.・Distribution and change of CO_2 and N_2O on the subtropical equator of the Pacific Ocean were clarified.・The modeling of the gas exchange process for the bubbles entrained in the breaker zone was made, and the validity was verified from an experiment under the condition of a single bubble.・It was succeeded to visualize the entrainmenet process of bubbles into water by the breakers from the results of bubble observation in the field using ultrasonic wave and video image shot simultaneously.・State of the art on the studies of air-water gas transfer phenomenon was investigated through the literature.

・通过对特殊摄像机拍摄的破碎图像进行可视化，分析了破碎区域中的气泡特性与波浪特性之间的关系。・提出了考虑破碎区域中夹带气泡影响的气体传输速度的模型公式。开发了一种用于测量破碎区流场的高精度图像分析技术。・应用激光诱导荧光，成功地将CO_2气体夹带进入水相的过程可视化。・发现这与溢出式破碎机相比，陷入式破碎机夹带气泡的穿透深度更深。・发现风浪中的膨胀促进气体转移，并且随着波浪周期变短，其效果变得更大。・评价了振动光栅湍流流场条件下水面的气体传递速度，发现该速度受大涡模型控制。・CO_2和N_2O在水面上的分布和变化。澄清了太平洋副热带赤道。・对破碎带中夹带的气泡的气体交换过程进行了建模，并通过单个气泡条件下的实验验证了有效性。・成功地根据使用超声波和同时拍摄的视频图像在现场观察气泡的结果，将破碎机将气泡夹带入水中的过程可视化。・通过文献调查了空气-水气体转移现象的研究现状。