Experimental study on the bubble-droplet chain process by using the world fastest high-speed video camera

利用世界最快高速摄像机进行气泡-液滴链过程的实验研究

• 批准号: 15360270
• 负责人: TAKEHARA Kohsei
• 金额: $ 7.49万
• 依托单位: Kinki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 2003
• 资助国家: 日本
• 起止时间: 2003 至 2005
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15360270/
• 关键词: gas transfer; water surfaces; wind waves; bubbles; droplets; 水滴生成; 気泡混入; 表面張力; 粘性; 気泡の破裂; 水滴の衝突; 水表面の物質輸送; 画像トリガー

Gas transfer at sea surfaces is strongly dominated by disturbances close to the surface. White cap, which appear on the ocean surfaces when wind waves are breaking, is one of the most important processes in the gas transfer mechanisms. In the white caps, many bubbles are entrained into sea water and some of them are lifted up to surface. The bubbles at sea surfaces eventually burst and generate many small droplets. Similarly, some of the droplet fall down to sea surface again. This bubble-droplet chain process was experimentally investigated in this research.A high-speed video camera, of which frame rate is 1,000,000 fps, was developed at Kinki University in 2001. The high-speed video camera is a powerful tool for investigation of the gas transfer at sea surface. In this research, this high-speed video camera was applied to visualization of the fundamental processes of the bubble-droplets chain process. The following processes are picked up as the fundamental processes.(1)Air entrapment under an impacting drop(2)Coalescence speed of two drops(3)Coalescence speed of two bubbles(4)Crown-breakup by the formation of Marangoni holesAnd also the simultaneous plane measurement techniques of air and water flows close to wind wave interfaces was developed by using a Particle Tracking Velocimetry, which was developed at Kinki University.

天然气在海面上的传输强烈地受到靠近海面的扰动的影响。白帽是气体输运机制中最重要的过程之一，它在风浪破碎时出现在海面上。在白色的帽子里，许多气泡被卷进海水中，其中一些被抬到水面上。海面上的气泡最终破裂并产生许多小水滴。同样，一些液滴再次落到海面上。本研究对这一气泡-液滴链条过程进行了实验研究。2001年，近木大学研制了一台帧速率为1,000,000 fps的高速摄像机。高速摄像机是研究海面气体传输的有力工具。在这项研究中，该高速摄像机被应用于气泡-液滴链过程的基本过程的可视化。(1)冲击液滴下的空气卷吸过程(2)两个液滴的聚合速度(3)两个气泡的聚合速度(4)Marangoni孔的形成导致的冠状破裂此外，还利用Kinki大学研制的粒子跟踪测速仪发展了风浪界面附近的空气和水流动的同时平面测量技术。

项目成果

100万枚/秒の高速CCDカメラの開発と応用

100万帧/秒高速CCD相机的研制与应用

• 发表时间: 2004
• 期刊: 顕微鏡 Vol. 39・No. 2
• 作者: T.Goji Etoh;Nao Otsuka;Toshiki Arai;Hideki Mutoh;Dirk Poggemann;Kohsei Takehara;T.Goji Etoh;Nao Ootsuka;Sigurdur T.Thoroddsen;Kohsei Takehara;江藤剛治
• 通讯作者: 江藤剛治

Applications of a 1 Mfps video camera to water surface phenomena

1 Mfps 摄像机在水面现象中的应用

• 发表时间: 2003
• 期刊: LA CINEMATOGRAPHIE ULTRA RAPIDE No.5
• 作者: Kohsei Takehara;Sigurdur T.Thoroddsen;T.Goji Etoh
• 通讯作者: T.Goji Etoh

画像計測による風波界面での気流・水流の相互作用に関する実験的研究

基于图像测量的风波界面空气与水流相互作用的实验研究

• 发表时间: 2003
• 期刊: 海岸工学論文集 第50巻
• 作者: H.Kitagawa;M.Mizohata;K.Kimura;Y.Nishida;T.Meguro;竹原 幸生
• 通讯作者: 竹原 幸生

Impacting jetting by a solid sphere

固体球体的冲击喷射

• 发表时间: 2004
• 期刊: Journal of Fluid Mechanics Vol.499
• 作者: S.T.Thoroddsen;T.G.Etoh;K.Takehara;Y.Takano
• 通讯作者: Y.Takano

Development of Simultaneous Plane Measurement Techniques of Air and Water Flows Close to Wind Wave Interfaces

靠近风波界面的空气流和水流平面同步测量技术的发展

• 发表时间: 2004
• 期刊: Proceedings of the 29^<th> International Conference, Coastal Engineering Vol.1
• 作者: Takehara;N.Ohtsuka;T.G Etoh;Y.Takano;G.Tsujimoto;N.Mizutani
• 通讯作者: N.Mizutani