| The research on aerodynamic force and wind pressure distribution characteristics of cylinder group has always been the most typical topic in fluid mechanics research,and it also has practical significance based on a large number of engineering background.At present,the research on aerodynamic force and wind pressure distribution characteristics of cylinder group is mainly focused on two circular cylinders,while the research on three circular cylinders is relatively less.The aerodynamic force and wind pressure distribution characteristics of three circular cylinders are quite different from those of single circular cylinder and double circular cylinders.It is of great significance to accurately grasp the aerodynamic force and wind pressure distribution characteristics of three circular cylinders for wind resistance design of practical engineering.In this paper,the research status of aerodynamic force and wind pressure distribution characteristics of cylinder group was systematically summarized.On this basis,the aerodynamic force and wind pressure distribution characteristics of three circular cylinders arranged inline were studied by using the rigid model pressure measurement wind tunnel test method under the condition of Reynolds number Re=6.4×10~4.The main work of this paper is as follows:(1)Three circular cylinders models and a device which can easily adjust the wind direction angleαand the spacing ratio L/D(L is the distance between the centers of two circular cylinders,D is the diameter of the circular cylinder)were designed and manufactured.The aerodynamic coefficients and wind pressure coefficients of three circular cylinders arranged inline under different working conditions were obtained by experiments.The range of wind direction angle was0°≤α≤90°and the range of spacing ratio was 1.2≤L/D≤4.0.The single circular cylinder and three circular cylinders in series were tested,and the test results were compared with the existing research results to verify the reliability of the test device and results.(2)The aerodynamic characteristics of three circular cylinders arranged inline were studied.The results show that the aerodynamic characteristics of three circular cylinders arranged inline could be roughly divided into three types according to the spacing:small spacing(1.2≤L/D≤2.0),medium spacing(2.5≤L/D≤3.0)and large spacing(3.5≤L/D≤4.0).According to the aerodynamic coefficient nephogram and curve,the aerodynamic interference law of three circular cylinders arranged inline under three types of spacing was summarized systematically,and the results were compared with those of single circular cylinder.(3)The wind pressure distribution characteristics of three circular cylinders arranged inline were studied.The results show that the wind pressure distribution characteristics of three circular cylinders arranged inline could be roughly divided into three types according to the wind direction angle:small wind direction angle(0°≤α≤25°),medium wind direction angle(30°≤α≤60°)and big wind direction angle(65°≤α≤90°).According to the wind pressure coefficient nephogram and curve,the wind pressure distribution of three circular cylinders arranged inline under three types of wind direction angles was summarized,and the results were compared with those of single circular cylinder. |
