caa a22 4500 606199098 CHVBK 20210128100937.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00348-015-2077-5 doi (NATIONALLICENCE)springer-10.1007/s00348-015-2077-5 Passive jet control of flow around a circular cylinder [Elektronische Daten] [Wen-Li Chen, Dong-Lai Gao, Wen-Yong Yuan, Hui Li, Hui Hu] In the present study, a passive flow control method, which is featured by passive windward suction combined with leeward jet over a circular cylinder for drag reduction and dynamic wind loading suppression, was experimentally investigated to manipulate unsteady wake vortex shedding from a circular cylinder. Four perforated pipe designs with different numbers of suction/jet holes (i.e., from 2 to 24 suction/jet holes) were used to create flow communicating channels between the windward and leeward stagnation points of a cylindrical test model. The experimental study was performed in a wind tunnel at a Reynolds number of Re=4.16×104 based on the cylinder diameter and oncoming airflow speed. In addition to measuring surface pressure distributions to determine the dynamic wind loads acting on the test model, a digital particle image velocimetry (PIV) system was also used to quantify the wake flow characteristics in order to assess the effectiveness of the passive jet control method with different perforated pipe designs, in comparison with a baseline case without passive jet control. It was found that the passive jet control method is very effective in manipulating the wake vortex shedding process from the circular cylinder. The perforated pipe designs with more suction/jet holes were found to be more effective in reducing drag and suppressing fluctuating amplitude of the dynamic wind loads acting on the test model. With 24 suction/jet holes evenly distributed over the cylindrical test model (i.e., the N13 design of the present study), the passive jet control method was found to be able to achieve up to 33.7% in drag reduction and 90.6% in fluctuating wind loading suppression, in comparison with the baseline case. The PIV measurement results revealed clearly that the passive jet control method would cause airflow jets into the cylinder wake and change the shedding modes of the wake vortex structures from the cylindrical test model. Because of the dynamic interactions between the passive jets and the wake vortex structures, the antisymmetric pattern of the wake vortex shedding was found to be converted to symmetric mode. The periodicity of the vortex shedding was also observed to be diminished and eventually disappeared with the number increase in the suction/jet holes. A linear stability analysis was performed to suggest that the passive jet flow would modify the wake stability of the circular cylinder by decreasing the disturbance growth rate in the immediate wake and pushing the region of absolute instability further downstream. Springer-Verlag Berlin Heidelberg, 2015 Chen Wen-Li Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, 150090, Harbin, Heilongjiang, China aut Gao Dong-Lai Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, 150090, Harbin, Heilongjiang, China aut Yuan Wen-Yong Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, 150090, Harbin, Heilongjiang, China aut Li Hui Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, 150090, Harbin, Heilongjiang, China aut Hu Hui Department of Aerospace Engineering, Iowa State University, 50011, Ames, IA, USA aut Experiments in Fluids Springer Berlin Heidelberg 56/11(2015-11-01), 1-15 0723-4864 56:11<1 2015 56 348 https://doi.org/10.1007/s00348-015-2077-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00348-015-2077-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chen Wen-Li Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, 150090, Harbin, Heilongjiang, China aut NATIONALLICENCE 700 1- Gao Dong-Lai Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, 150090, Harbin, Heilongjiang, China aut NATIONALLICENCE 700 1- Yuan Wen-Yong Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, 150090, Harbin, Heilongjiang, China aut NATIONALLICENCE 700 1- Li Hui Key Lab of Structures Dynamic Behavior and Control (Harbin Institute of Technology), Ministry of Education, 150090, Harbin, Heilongjiang, China aut NATIONALLICENCE 700 1- Hu Hui Department of Aerospace Engineering, Iowa State University, 50011, Ames, IA, USA aut NATIONALLICENCE 773 0- Experiments in Fluids Springer Berlin Heidelberg 56/11(2015-11-01), 1-15 0723-4864 56:11<1 2015 56 348