Enhancement of Mass Transfer into a Falling Liquid Film by Two-Dimensional Waves

二维波增强落下液膜的传质

• 批准号: 05650201
• 负责人: NAGATA Takashi
• 金额: $ 1.47万
• 依托单位: UNIVERSITY OF RYUKYUS
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05650201/
• 关键词: Liquid Film; Surface Wave; Gas Absorption; Mass Transfer; Liquid Film Type Absorber; 液膜式吸収器; 吸収器

Two-dimensional waves are excited on a falling laminar water film with input of controlled disturbances. and the augmentation in absorption rate of the film from the surrouding gas by the waves are experimentally determined at the room temperature. Two-dimensional waves appear on the whole surface of the film in the range of wave frequencies 10-30Hz, and otherwise waves coalesce with each other to become three dimensional. The augmentation decreases momotonecally with wave frequency at low Reynolds numbers Re<20. while increases at high Reynolds numbers Re>20. Two-dimensional waves increase in absorption rate with Reynolds number. and the rate becomes 2.5 times larger than the values for flat surface films at Reynolds numbers Re>50.Taking account of these results and the numerical observations by Nagasaki and Hijikata (1990) and others, the double boundary layr model is built up, inwhich the mass transfer coefficient alpha is expressed as alpha=xiROO<3.46Dlpif_w>, where D and f_w are diffusivity and wave frequency, introducing the parameter for sweeping motion of high concentration layr near the surface by the waves xi. It is found that the parameter is a function only of wave velocity at the given physical properties of the liquid and increases monotonically with wave velocity.

二维波在掉落的层流膜上激发，并输入受控干扰。在室温下，通过从波浪的气体中获得的薄膜吸收速率的增强速率是在室温下确定的。二维波在膜的整个表面上以10-30Hz的范围出现，否则波浪彼此合并以成为三维。雷诺数在低雷诺数下的波频率RE <20，增强量会随着波频率而降低。而在高雷诺数下增加> 20。二维波在雷诺数中的吸收率增加。速率比Reynolds数字的平面表面膜值高2.5倍。传质系数的alpha表示为alpha = xiroo <3.46dlpif_w>，其中d和f_w是扩散性和波频频率，引入了通过波XI在表面上扫描高浓度Layr的参数。发现该参数仅在液体的给定物理特性下仅在波速下的函数，并以波速为单调地增加。

项目成果

吉村、野底、長田: "周期的に誘起された表面波による液膜のガス吸収促進" 第31回日本伝熱シンポジウム講演論文集. 2. 769-771 (1994)

Yoshimura、Nosoko 和 Nagata：“周期性诱导表面波促进液膜中的气体吸收”第 31 届日本传热研讨会论文集 2. 769-771 (1994)。

N.P.Yoshimura,T.Nosoko and T.Nagata: "Characteristics of Two-Dimensional Waves on a Falling Liquid Film" submitted to Chemical Engineering Science.

N.P.Yoshimura、T.Nosoko 和 T.Nagata：“降落液膜上的二维波的特征”提交给《化学工程科学》。

野底、吉村、長田: "二次元表面波を伴う層流流下液膜のガス吸収のモデル化" 第32回日本伝熱シンポジウム講演論文集. in press. (1995)

Nosoko、Yoshimura 和 Nagata：“二维表面波层流下液膜中的气体吸收建模”第 32 届日本传热研讨会论文集（1995 年）。

T.Nosoko,T.Nagata and K.Oyakawa: "A Study on a Draining Film Associated with Condensation or Evaporation" The International Symposium on Two-Phase Flow Modelling and Experimentation,in press.(1994)

T.Nosoko、T.Nagata 和 K.Oyakawa：“与冷凝或蒸发相关的排水膜的研究”，国际两相流模拟和实验研讨会，出版中。（1994 年）

T.Nosoko,T.Nagata,et al.: "Visualization of deaining film profiles by laser interferometry," Proceedings of the 3rd Asian Symposium on Visualization. 438-441 (1994)

T.Nosoko、T.Nagata 等人：“通过激光干涉测量法实现脱铝薄膜轮廓的可视化”，第三届亚洲可视化研讨会论文集。