Turbulent Model of Coherent Structures in a Transitional Boundary Layer

过渡边界层相干结构的湍流模型

• 批准号: 13650178
• 负责人: MAKITA Hideharu
• 金额: $ 2.18万
• 依托单位: Toyohashi University of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13650178/
• 关键词: Boundary Layer; Transition; Turbulent Spots; Horseshoe Vortex; Turbulent Bulge; Flow Control; Flow Visualization; Conditional Measurement

In order to experimentally study interaction phenomena between turbulent spots in a laminar boundary layer or horseshoe vortices in a turbulent boundary layer, a pair of turbulent spots or horseshoe vortices was artificially developed in each boundary layer. Then, a synthetic transitional boundary layer was generated by inducing many turbulent spots to clarify the effects of their interaction process on the structure of the boundary layer. To observe the vortex structure, coherent velocity and vorticity components were obtained trough conditional hot-wire measurement.(1)The longitudinal vortex at each inside wingtip comes into contact, as the two spots begin to merge. Mutual interaction between them generates a strong upwash and give birth to a strong velocity-defect region in the upper merged region.(2)The spanwise vortices constitute the heads of large-scale horseshoe vortices connecting the longitudinal vortices beneath and may grow into turbulent bulges in the downstream turbulent boundary layer. As the array of turbulent spots grows up into a turbulent boundary layer, its periodical structure survives still around the boundary layer's outer edge.(3)The merged horseshoe vortices grew to be a single larger horseshoe vortex in the downstream region, when two horseshoe vortices were induced simultaneously.(4)When the two horseshoe vortices were induced with time delay of 20msec, they are not connected with each other and apparently, their inside legs were not separated from each horseshoe vortex.

为了通过实验研究层流边界层中的湍流点或湍流边界层中的马蹄涡之间的相互作用现象，在每个边界层中人为地形成一对湍流点或马蹄涡。然后，通过诱导许多湍流点生成合成过渡边界层，以阐明它们的相互作用过程对边界层结构的影响。为了观察涡结构，通过条件热线测量获得了相干速度和涡度分量。(1)随着两个点开始合并，每个内侧翼尖处的纵向涡开始接触。它们之间的相互作用产生强烈的上洗流，并在上部合并区产生强烈的速度缺陷区。(2)展向涡构成了连接下方纵向涡的大型马蹄涡的头部，并可能在下游湍流边界层中成长为湍流凸起。当湍流点阵列成长为湍流边界层时，其周期性结构仍然存在于边界层外缘周围。（3）当同时诱发两个马蹄涡时，合并的马蹄涡在下游区域成长为单个较大的马蹄涡。（4）当延迟20毫秒诱发两个马蹄涡时，它们彼此不相连，显然，它们的马蹄涡不相连。 内侧的腿没有与每个马蹄形漩涡分开。

项目成果

蒔田秀治他3名: "乱流境界層中における大規模馬蹄渦の相互干渉に関する実験的研究"日本流体力学会誌「ながれ」. 21. 42-43 (2002)

Hideharu Makita等3人：“湍流边界层中大尺度马蹄形涡流相互干扰的实验研究”日本流体力学学会杂志“Nagare”21. 42-43（2002）。

H.Makita et al.: "An Experimental Study of Interaction between Two Horseshoe Vortices in a Turbulent Boundary Layer"Proceedings of 2002 Meeting of Japan Society of Fluid Mechanics. 21. 42-43 (2002)

H.Makita 等人：“湍流边界层中两个马蹄形涡流相互作用的实验研究”日本流体力学学会 2002 年会议论文集。

H.Makita et al.: "Interaction between Two Horseshoe Vortices in a Turbulent Boundary Layer"Proceedings of Tokai Department Meeting of Japan Society of Mechanical Engineering. No.023-2. 89-90 (2002)

H.Makita 等人：“湍流边界层中两个马蹄形涡流之间的相互作用”日本机械工程学会东海部会议论文集。

蒔田 秀治他3名: "乱流境界層中における馬蹄形渦の相互干渉(渦構造の変形とレイノルズ応力に関する考察)"航空宇宙技術研究所特別報告. SP. (2003)

Hideharu Makita等3人：“湍流边界层中马蹄形涡流的相互干扰（涡流结构变形和雷诺应力的讨论）”航空航天技术研究所的特别报告（2003）。

H.Makita et al.: "Mutual Interaction between Horseshoe Vortices in a Turbulent Boundary Layer"Special Publication of National Aerospace Laboratory SP. (2003)

H.Makita 等人：“湍流边界层中马蹄形涡流之间的相互相互作用”国家航空航天实验室 SP 的特别出版物。