PARTICLE MOTION AND FLUCTUATING FORCES APPLIED ON A SPHERICAL PARTICLE IN TURBULENT SHEAR FLOWS WITH LINEAR VELOCITY GRADIENT

具有线速度梯度的湍流剪切流中的颗粒运动和施加在球形颗粒上的脉动力

• 批准号: 63550131
• 负责人: YAMAMOTO Fujio
• 金额: $ 1.22万
• 依托单位: FUKUI 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: 1988
• 资助国家: 日本
• 起止时间: 1988 至 1989
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-63550131/
• 关键词: Linear Turbulent Shear Flow; Gas-solid Two-phase Flows; Sphere; Fluctuating Lift and Drag; Drop Test; Trajectory; Velocity Gradient; Phase Averaging Method; 固気二層流; 空気輸送; シミュレーション; 円柱; 揚力; 抗力; 変動圧力

(1) The time-mean pressure distributions on the surfaces of test spheres fixed in the two-dimensional vertical duct whose flows were turbulent linear shear flows were measured, and time-mean lift and drag were computed by surface integration of the pressure distributions. The results are summarized as;(a) The lift is applied on a sphere in the direction from the higher velocity side to the lower velocity side of the duct flow. (b) The lift increased nearly proportionally with increasing the velocity gradient of the shear flow. (c) The value of drag is scarcely dependent on the velocity gradient. Whereas the test range of non-dimensional velocity gradient was 0 to 0.6, and the test range of sphere Reynolds number was 16900 to 35000.(2) The drop tests of a sphere with the diameter 5 or 10mm were carried out in the vertical duct. The photographs of the trajectories of a dropping sphere were taken. The good agreements were found between the trajectories by experiments and those by numerical simulations. It was reconfirmed that the lift application agrees well with the results as described above. Whereas the test range of sphere Reynolds number was 4000 to 7000.(3) The fluctuating pressure distributions on sphere surfaces was measured with a high sensitive pressure transducer. A new phase averaging method was applied to the measurement of the fluctuating lift and drag. It was found that the values of the fluctuating parts of lift and drag were negligibly small in comparison with their steady parts. It may be said that the reason is because the turbulence intensity of the main duct flows was not so great and the shedding eddy induced fluctuating forces applied on a sphere were small.

(1)测量了固定在二维垂直管道内的测试球体表面的时间平均压力分布，并对压力分布进行表面积分计算时间平均升力和阻力。研究结果总结如下：(a)升力作用在一个球体上，方向是从风管流动的高流速侧到低流速侧。(b)随着剪切流速度梯度的增大，升力几乎成正比地增大。(c)阻力值几乎不取决于速度梯度。而无因次速度梯度的测试范围为0 ~ 0.6，球体雷诺数的测试范围为16900 ~ 35000。(2)在垂直风道中进行了直径为5或10mm的球体的跌落试验。拍下了一个落球的轨迹照片。实验结果与数值模拟结果吻合较好。再次证实，举升应用与上述结果吻合良好。而球体雷诺数的测试范围为4000 ~ 7000。(3)采用高灵敏度压力传感器测量了球面上的脉动压力分布。提出了一种新的相位平均法来测量波动升力和阻力。研究发现，与稳定部分相比，升力和阻力的波动部分的值可以忽略不计。可以说，这是因为主风道流动的湍流强度不是很大，而由脱落涡引起的作用在球体上的脉动力很小。

项目成果

山本富士夫、紋谷英樹、幸川光雄、寺西厚、玉田裕之: "A STUDY OF MOTION OF A SPHERE IN LINEAR TURBULENT SHEAR FLOW THROUGH VERTICAL DUCT" PROCEEDINGS OF FIRST INTERNATIONAL CONFERNCE ON MECHANICS OF TWO-PHASE FLOWS(Taiwan,Taipei). 45-50 (1989)

Fujio Yamamoto、Hideki Monya、Mitsuo Yukikawa、Atsushi Teranishi、Hiroyuki Tamada：“通过垂直管道的线性湍流剪切流中球体运动的研究”第一届国际两相流力学会议论文集（台湾，台北）。 45-50 (1989)

Fujio YAMAMOTO, Hideki MONYA, Mitsuo KOUKAWA, Atsushi TERANISHI and Hiroyuki TAMADA: "A STUDY OF MOTION OF A SPHERE IN LINEAR TURBULENT SHEAR FLOW THROUGH VERTICAL DUCT" Proc. of FIRST INTERNATIONAL CONFERENCE ON MECHANICS OF TWO-PHASE FLOWS, pp.45-50, 19

Fujio YAMAMOTO、Hideki MONYA、Mitsuo KOUKAWA、Atsushi TERANISHI 和 Hiroyuki TAMADA：“通过垂直管道的线性湍流剪切流中球体运动的研究”Proc。

Fujio YAMAMOTO, Mitsuo KOUKAWA, Hideki MONYA, Atsushi TERANISHI and Hiroyuki TAMADA: "Fluid Forces Applied on a Circular Cylinder and a Sphere in Linear Turbulent Shear Flows" Proc. of '89 Symposium on Multi-phase Flows, pp.97-100, 1989 (Kobe, Japan).

Fujio YAMAMOTO、Mitsuo KOUKAWA、Hideki MONYA、Atsushi TERANISHI 和 Hiroyuki TAMADA：“线性湍流剪切流中圆柱体和球体上的流体力”Proc。

山本富士夫,幸川光雄,紋谷英樹,寺西厚: 日本機械学会講演概要集. No.887-2. 44-45 (1988)

Fujio Yamamoto、Mitsuo Yukikawa、Hideki Monya、Atsushi Teranishi：日本机械工程师学会讲座摘要第 887-2 号（1988 年）。

Fujio YAMAMOTO, Mitsuo KOUKAWA, Hideki MONYA and Atsushi TERANISHI: "PARTICLE LIFT AND DRAG FORCES IN LINEAR TURBULENT SHEAR FLOWS" Proc. of FIFTH WORKSHOP ON TWO-PHASE FLOW PREDICTIONS, 1990 (FRG, Erlangen).

Fujio YAMAMOTO、Mitsuo KOUKAWA、Hideki MONYA 和 Atsushi TERANISHI：“线性湍流剪切流中的粒子升力和拖曳力”Proc。