| 论文简介 |
Flow Structure of the Entrance of a T-junction Duct
without/with a Circular Cylinder
Xiaoyu Wang1, Jing He1, Bo Su1, Hanbing Ke2, Mei Lin1*, Yitung Chen3
1. School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, 710049, China
2. Science and Technology on Thermal Energy and Power Laboratory, Wuhan, 430205, China
3. Department of Mechanical Engineering, University of Nevada-Las Vegas, Las Vegas, NV 89154-4027, USA
*Corresponding author: janeylinm@mail.xjtu.edu.cn
Tel and Fax: +86-29-82667936
Abstract: The flow characteristics of the trailing edge of vertical vanes installed at the intersection of a T-junction duct were experimentally investigated using particle image velocimetry (PIV). The measured area is ranged from the trailing edge of vertical vanes to 1.26 times hydraulic diameter length downstream of the branch duct in the symmetrical plane. The measured velocity field in the branch duct with/without single circular cylinder was carefully studied under different cross velocities and velocity ratios. Additionally, the effect of the locations of single cylinder on the flow field was also discussed. The common results of three typical flow regions, which are characterized as the positive velocity region, the unsteady flow region and the trailing edge flow region of the vane, have been visually observed in the measured area. The positive velocity region existed in almost one half of the measured area, and the velocity peak appeared at the down wall of the branch duct. As for the unsteady flow region, the unstable double-vortex structure transformed into a single-vortex structure as the velocity ratio increased. As for the trailing edge flow region of the vanes, the vortex streets could be visualized. Furthermore, the location of single cylinder has revealed significant influence on the flow distributions in the trailing edge flow regions of the vanes as compared to the other two flow regions. The flow structure without cylinder in the measured area is dependent on different combinations of the cross velocity and velocity ratio, whereas the flow structure with cylinder is dependent on the velocity ratio. The vorticity fields were also analyzed in each region. The streamwise and wall-vertical velocity components have revealed the cause of the direction of the airflow trajectory in detail.
Keywords: Particle Image Velocimetry (PIV); T-junction; Vanes; Cylinder; Flow Field |
(创新港)
