Development of Liquid Atomization lnduced by Laminar-Turbulent Transition of Free Liquid Film Flow and Elucidation of the Atomization Mechanism

自由液膜流层流-湍流转变诱导液体雾化的进展及雾化机理的阐明

• 批准号: 08650219
• 负责人: AZUMA Tsuneo
• 金额: $ 1.41万
• 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 (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08650219/
• 关键词: Laminar-turbulent transition; Llquid atomization; Liquid film flow; Radial flow; Boundary layr; lnstability; 自由液膜流; 安定性; 放射状流れ; 速度分布; 境界層

The disintegration of a radially thinning liquid sheet into drops, which is induced directly by the transition from laminar to turbulent flow, is investigated.The liquid sheet in the present experiment is generated as follows ; a radial liquid film flow is formed by a tap water issue from a thin cylindrical gap, which is constructed by the end of a circular pipe and the flat surface of a circular plate, to suppress the turbulence of the flow to the utmost. The liquid film flows radially outward on the plate, detaching from the peripheral edge of the plate, and then the liquid flows outward as a radially thinning liquid sheet in still air.Although the liquid aheet is laminar with a smooth liquid surface under the low Reynolds number flow, the transition of the thin liquid sheet begins to occur at a location of several millimeters downstream of the plate edge at high Reynolds number flow, being attributable to the velocity profile having an inflection point dueto the removal of the shear … More stress on the wall. The intensity of the turbulence increases with the Reynolds number, and the turbulence begins to sporadically perforate the liquid sheet at a immediately downstream location from the plate edge. A further increase in the number of perforation with the discharge Reynolds number causes to decreasing in sizes of webs and strands, and finally, the configuration of the web of strand does not appear in the liquid sheet and the transition results in the sudden breakup of the sheetinto drolets and clumps. The sizes of droplets are several tens micrometers and those of clumps are several hurdreds to some thousands micrometers.Although the quality of the disintegration rises further with the stagnant pressure, there are two limitations. The one is that the liquid film flow at the plate edge must have a fully developed velocity distribution, and the other is that no transition occurs in the flow on the plate. Flow conditions for the effective disintegration directly due to the transition of the liquid sheet are also clarified. Less

研究了从层流到湍流的过渡，将径向变薄的液体片分解为液滴。径向液膜流是由薄圆柱间隙的自来水问题形成的，该圆柱间隙由圆形管的末端和圆形板的平坦表面构成，以抑制最大的流量。液体膜从板上彻底向外流动，从板的周围边缘脱离，然后液体在静止空气中的径向变薄的液体板上向外流动。尽管液体板是层状的，层层层状在较低的雷诺数下方平稳的液体表面流动，液体的液体流在薄液体的过渡中，在几个板块的位置出现在板块的位置。由于去除剪切的速度……壁上的压力更大，因此具有拐点的速度曲线。湍流的强度随雷诺数的增加而增加，湍流开始从板边缘立即下游位置零星穿孔液体板。雷诺的排放雷诺数的进一步增加，导致网站和链的大小减少，最后，链链的构型不会出现在液体板上，并且过渡导致Sheetto drounto drollets and Clips的突然破裂。液滴的尺寸是几千米，夹子的尺寸是数千微米的几个humdred。一个是，板边缘处的液体膜流动必须具有完全开发的速度分布，另一个是板上的流中没有过渡。还阐明了由于液体板的过渡而直接导致有效分解的流动条件。较少的

项目成果

T.AZUMA and T.WAKIMOTO: "Breakup and Drop Formation of a Radial Liquid Sheet Induced by Laminar-Turbulent Transition" Proc.3rd Int.Conf.on Multiphase Flow,ICMF′98. (to be published). (1998)

T.AZUMA 和 T.WAKIMOTO：“层流湍流转变引起的径向液体层的破裂和液滴形成”Proc.3rd Int.Conf.on Multiphase Flow，ICMF′98（待出版）。

Tsuneo AZUMA: "Instability and Transition in a Radial Boundary Layer Flow" JSME CENTENNIAL GRAND CONGRESS,Proc.Int.Conf.on Fluid Engineering,. 1. 339-344 (1997)

Tsuneo AZUMA：“径向边界层流中的不稳定性和过渡”JSME 百年大大会，Proc.Int.Conf.on 流体工程，。

脇本 達郎、東 恒雄: "放射状自由液膜流れの乱流遷移による液体微粒化に関する研究" 日本機械学会論文集(B編). 64(to be published). (1998)

Tatsuo Wakimoto、Tsuneo Higashi：“径向自由液膜流湍流转变引起的液体雾化研究”，日本机械工程师学会会刊（B 版）（1998 年）。

Tsuneo AZUMA and Tatsuro WAKIMOTO: "Breakup and Drop Formation of a Radial Liquid Sheet Induced by Laminar-Turbulent Transition" Proc.3rd Int.Conf.on Multiphase Flow, ICEF'98. (to bu published). (1998)

Tsuneo AZUMA 和 Tatsuro WAKIMOTO：“层流-湍流转变引起的径向液体层的破裂和液滴形成”Proc.3rd Int.Conf.on 多相流，ICEF98。

Tatsuro WAKIMOTO and Tsuneo AZUMA: "Liquid Atomization of a Radial Liquid Sheet Due to Transition to Turbulence" Trans.of Japan Soc.Mech.Engrs. (in Japanese). (to be published).

Tatsuro WAKIMOTO 和 Tsuneo AZUMA：“由于过渡到湍流而导致径向液体层的液体雾化” Trans.of Japan Soc.Mech.Engrs。