Study of Flow Fields of a Cylinder Near a Plane Boundary

• Main Authors: CHING-CHIH TSAI, 蔡清智
• Other Authors: Minter Cheng Ph.D.
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/26844832302318570538

碩士 === 逢甲大學 === 材料與製造工程所 === 96 === The objective of this research is to investigate the flow interference phenomenon of a circular cylinder near a plane boundary, arranged side-by side in cross flow with various pitch ratios at Reynolds number of 1000. The analysis was performed by using the FLUENT software, The flow forces acting on the main cylinder, flow characteristics, and Strouhal numbers are investigated for different gap-ratios of the cylinders. Learnt by the analysis result, when the interval G/D is 3.5, cylinder and plate have not interfered with the phenomenon and taken place each other, the in other words single cylinder, with putting in freedom flows in a plate. When G/D reduces, postpone and then the trend that move ahead of time first in some positions of separation of layer of dull and stereotyped border. At G/D≧1.8, the vortex shedding frequency of cylinder does not change; At 1.2≦G/D＜1.8, the increase of vortex shedding frequency dwindling of the intervalin; At G/D =1.2 reach all interval of maximums vortex shedding frequency. At G/D＜1.2 vortex shedding frequency reduce and appear, lower trend with interval.