Flip-Flop Flow Mechanism in Diamond-Shaped Cylinder Bundles

菱形圆柱束中的触发器流动机制

• 批准号: 14550166
• 负责人: SHINZABURO Umeda
• 金额: $ 1.41万
• 依托单位: FUKUYAMA University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2003
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14550166/
• 关键词: Flip-flop flow; Diamond-shaned cylinder bundle; Intersecting flow; LDV; PIV; Edge-tone

A self-induced flip-flop flow phenomenon in diamond-shaped cylinder bundles has been disclosed, in previous studies by the authors. The flip-flop flow oscillation promotes fluid mixing and thus contributes to an enhancement in convective heat and mass transfer when the cylinder bundles are used as heat and mass exchanger equipment. In the present study, both two-dimensional particle image velocimetry(PIV) and two-dimensional laser Doppler velocimetry(LDV) were performed to observe and monitor flow phenomena in diamond-shaped cylinder bundles for the purpose of investigating flip-flop flow mechanisms. The following summary is derived from this study:The mechanisms for the occurrence of flip-flop flow oscillation in the flow channels of a diamond-shaped cylinder bundle are summarized in the form of a flow chart. It consists of necessary and auxiliary conditions. The necessary conditions include the generation of separation vortices, fluctuations of von Karman vortex sheets, occurrence of Coanda effect, and variation of flow cross-sectional areas. Intersecting flows, ramming effect, energy source point and shear layer oscillation are considered the auxiliary conditions. A minimum of three rows in a cylinder bundle warrants the occurrence of edge-tone phenomenon(generation of pressure wayes) at the leading edge of the fourth-row cylinder and the reciprocating migration of a conjunct separation vortex pair across the rear apex of the third-row cylinder. The latter triggers the fluctuation of flip-flop flow downstream in a diamond-shaped cylinder bundle of more than five rows and a stable swinging of exit jets from the bundle.

作者在以前的研究中发现了菱形柱束中的自诱导翻转流动现象。当管束用作热质交换设备时，触发器流动振荡促进流体混合，从而有助于对流传热和传质的增强。在本研究中，两个二维粒子图像测速（PIV）和二维激光多普勒测速（LDV）进行观察和监测的流动现象，在菱形柱束的目的是研究触发器的流动机制。本文的主要工作如下：以流程图的形式总结了菱形柱束流道中触发流振荡的发生机理。它包括必要条件和辅助条件。其必要条件包括分离涡的产生、卡门涡面的波动、附壁效应的发生和流动截面积的变化。辅助条件考虑了交叉流、夯击效应、能量源点和剪切层振荡。最少三排的气缸束保证了边缘音现象的发生（压力波的产生）在第四排气缸的前缘和一个联合分离涡对的往复迁移通过第三排气缸的后顶点。后者触发的触发器流下游的五排以上的菱形柱束和出口射流从束的稳定摆动的波动。

项目成果

梅田眞三郎, 長谷川盛三, 園尾昌洋, Wen-Jei Yang: "菱形角柱群流路内の分流領域における流速変動特性"日本機械学会2003年度年次大会講演論文集. 03-1. 253-254 (2003)

梅田慎三郎、长谷川森三、园野正宏、杨文杰：《菱形棱柱流道导流区域流速脉动特性》日本机械工程学会2003年年会论文集03-1。 253-254（2003）

梅田眞三郎, 長谷川盛三, 谷口輝, Wen-Jei Yang: "菱形角柱群流路内におけるフリップ・フロップ流れの発現メカニズム"福山大学工学部紀要. 第27巻. 35-63 (2003)

梅田新三郎、长谷川森三、谷口辉、杨文杰：“菱形棱柱流道中的翻转流的发展机制”福山大学工学部学报，第 27 卷，35-63（2003 年）

S.Umeda, W.-J.Yang: "Flow Instability in Diamond Shaped Cylinder Bundles by Means of LDV and PIV"Proceedings of PSFVIP-4. F4063 (2003)

S.Umeda, W.-J.Yang：“通过 LDV 和 PIV 实现菱形圆柱束的流动不稳定性”PSFVIP-4 论文集。

S.Umeda, A.Taniguchi, S.Hasegawa, W.-J.Yang: "Flow Instability in Diverging-Flow Region with Flip-Flop Phenomenon inside Diamond-Shaped Cylinder Bundles"Proceedings of 4^<th> ASME/JSME Joint Fluids Engineering Conference. FEDSMO3, July. (2002)

S.Umeda、A.Taniguchi、S.Hasekawa、W.-J.Yang：“钻石形圆柱束内具有 Flip-Flop 现象的分流区域中的流动不稳定性”第 4 届 ASME/JSME 联合会议论文集

S.Umeda, S.Hasegawa, A.Taniguchi, W.-J.Yang: "Flip-Flop Flow Mechanism in Diamond-Shaped Cylinder Bundles"The Memoirs of the Faculty of Engineering, (Fukuyama University). Vol.27, December. 35-64 (2003)

S.Umeda、S.Hasekawa、A.Taniguchi、W.-J.Yang：“菱形圆柱束中的触发器流动机制”工学部回忆录，（福山大学）。