Study on Transition Suppressions in Pipe Flow and Radial Liquid-Film Flow by Surfactant Additives

表面活性剂添加剂抑制管流和径向液膜流转变的研究

• 批准号: 06805019
• 负责人: AZUMA Tsuneo
• 金额: $ 1.28万
• 依托单位: Osaka City University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1994
• 资助国家: 日本
• 起止时间: 1994 至 1995
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-06805019/
• 关键词: Laminar-turbulent transition; Surfactant additives; Pipe flow; Liquid film flow; Radial flow; Critical Reynolds number; Transition suppression; 液膜流; 管内流れ

The effects of surfactant additives on the laminar-turbulent transitions of a pipe flow and a radial liquid film flow were studied experimentally. Dodecyl-benzensulfonicacid sodium was used as the surfactant. The concentration of solution was varied from 5 to 100 wppm.For the pipe flow experiment, stainless steel-, copper-, glass- and Teflon-tubes, which have a inner diameter of 2.5mm, were used as the test pipe. The critical Reynolds numbers were obtained under conditions of both gradual increasing and decreasing Reynolds number. These critical Reynolds numbers monotonously increased with surfactant concentration until these values came to be about ten percent higher than that of tap water at a concentration of 20 wppm, and then decreased with further increasing concentration.For the radial liquid film flow experiment, the flow was generated by a water discharge through a gap between the top of a circular brass nozzle and the lower surface of a glass plate, flowing radially in a thin liquid film along the plate. The inner diameter of the nozzle was 15mm and the distance of the gap 1mm. Experimental results showed that the transition radius increases quickly with the concentration bellow 6 wppm, after then does not change with the further increasing concentration. Furthermore, a lot of data on the critical Reynolds number of solution under various concentrations ranging from 6 wppm to 76 wppm indicated about 1.08 times as great as that of the solvent. Consequently, a small amount of additives of surfactant suppresses evidently the transition although its amount is only 5 to 8 percents.

实验研究了表面活性剂添加剂对管流和径向液膜流层流-湍流转捩的影响。十二烷基苯磺酸钠用作表面活性剂。溶液浓度在5 ~ 100 wppm范围内变化。管流实验分别采用内径为2.5mm的不锈钢管、铜管、玻璃管和聚四氟乙烯管。在雷诺数逐渐增加和逐渐减少的情况下，得到了临界雷诺数。这些临界雷诺数随着表面活性剂浓度的增加而单调增加，直到这些值比浓度为20 wppm的自来水高出约10%，然后随着浓度的进一步增加而降低。对于径向液膜流实验，通过圆形黄铜喷嘴的顶部和玻璃板的下表面之间的间隙排放水来产生流动，在薄液膜中沿板沿着径向流动。喷嘴内径为15 mm，差距距离为1 mm。实验结果表明，在6 wppm以下，过渡半径随浓度的增加而迅速增大，6 wppm以后，过渡半径不再随浓度的增加而变化。此外，大量的数据表明，在6 - 76 wppm范围内的各种浓度下的溶液的临界雷诺数约为溶剂的1.08倍。因此，少量的表面活性剂的添加剂，虽然其量仅为5 - 8倍，但明显抑制了该转变。

项目成果

Tsuneo AZUMA ほか1名: "Stabilityand Transition to Turbulence of a thin Liquid-Film Jet" ASME,FED. 225. 155-162 (1995)

Tsuneo AZUMA 和其他 1 人：“薄液膜射流的稳定性和湍流过渡”ASME，FED。225. 155-162 (1995)

Tsuneo AZUMA: "Laminar-Turbulent Transition of Thin Liquid Film Flow on a Stationary and Rotating Disk" Proc.Int.Symp.on Heat and Mass Transfer, Kyoto.85-90 (1994)

Tsuneo AZUMA：“固定和旋转盘上薄液膜流的层流-湍流转变”Proc.Int.Symp.on 传热传质，Kyoto.85-90 (1994)

Tsuneo AZUMA: "An Experiment on Transition of Three-Dimensional Boundary Layer" IUTAM Symp.on Laminar-Turbulent Transition '94. 307-314 (1995)

Tsuneo AZUMA：“三维边界层转变的实验”IUTAM Symp.on Laminar-Turbulent Transition 94。

加藤,東ほか1名: "放射状液膜流れの伝熱特性(乱流遷移点近傍での局所熱伝達特性" 日本機械学会論文集B編. 61. 3755-3763 (1995)

Kato, Azuma 等人：“径向液膜流的传热特性（湍流转变点附近的局部传热特性”）日本机械工程师学会汇刊，B 版 61. 3755-3763 (1995)。

Tsuneo AZUMA,Tatsuroh WAKIMOTO: "Stability and Transition to Turbulence of a THin Liquid Film Flow" Amer.Soc.Mech.Eng.,Fluid Eng.Div.225. 155-162 (1995)

Tsuneo AZUMA、Tatsuroh WAKIMOTO：“薄液膜流的稳定性和湍流过渡”Amer.Soc.Mech.Eng.，流体工程Div.225。