Numerical Simulation Of Flow Control Around Square Cylinder Based On The Moving Surface Boundary-layer Control

With the emerging of light and flexible structures, such as tall buildings and super high-rise buildings, wind resistance design has graduall y become an important factor which should be considered in various structural designs. Moving surface boundary-layer control(MSBC) is one of the most effect ive act ive flow control measures, and has good applicat ion prospect in many fields. Therefore, deeper research on the aerodynamic force and wake characterist ics of bluff body by MSBC is relat ively meaningful and valuable to wind resistance design. Based on Fluent software platform, the basic control parameters of MSBC which contain the diameter parameter and position parameter of rotating cylinder are opt imized in the study. The effect on the performance of flo w control of single square cylinder by MSBC has been studied in detail. In order to provide reference for wind resistance design, further study on flow control of single square cylinder and two square cylinders has been researched at different condit ions based on the optimal model parameters. The main research contents in this paper are shown as followings:The flow around the square cylinder at low Reynolds number(Re=200) is numerical simulated based on Laminar model in the paper. And the process of vortex shedding and characteristics of flow field are analyzed. Compared wit h the previous studies, the simulat ion results reveal that the numerical mo del is much more reliable. Then, further study on wake control mechanism by MSBC is done when the rotating cylinder has a large diameter. The lift and drag force, frequency characterist ics and pressure distribution are discussed in detail, which lays a solid foundat ion for parameter opt imization in the next research.In order to minimize the space occupied by rotating cylinder, the flo w control effect of diameter of rotat ing cylinder in the range of 0.02 D~0.10D(D is the side length of the square cylinder) is discussed in this paper. Then, based on the optimum diameter parameter, the influence of arrangement of rotating cylinder in along-wind direct ion and transverse direct ion is invest igated. Fro m the results, we can get the effect ive arrangement of rotat in g cylinder and its best posit ion so that the opt imal model of MSBC is determined. To get the effect ive range of wind angle of flow control and provide reference for its applicat ion in pract ical engineering, the control effect of single square cylinder by M SBC at different wind directions is studied based on the optimum parameters.The flow around two square cylinders which are arranged in-line and side-by-side is simulated in the paper. The changes of aerodynamic force, flow field characterist ics and interact ion between them at different spacing rat io are studied. Then, MSBC is adopted to control the adverse situat ions when the spacing L=5D for in-line situation and H=2D for transvers situat ion. And the aerodynamic force and wake structure are researched with the changes of angular mo mentum. The results show that MSBC can reduce the aerodynamic force and improve the wake structure for two square cylinders. The work laid a fir m foundation for its practical application in the group structures.