Interference Effect Of Aerodynamic Force And Wind Pressure Distribution Of Three Cylinders In A Line

Circular Cylindrical structures and buildings are common in practical engineering,such as cooling towers,chimneys and stay cables,etc.Under the action of wind,the interaction among the cylinders in a group of cylinders is different from that of a single cylinder in aerodynamic characteristics.Researchers have done more research on two cylinders,but less on three cylinders.three cylinders in a line are a common arrangement of three cylinders.Therefore,it is of great significance to study the interference effect of three cylinders in a line.Firstly,the research status of aerodynamic characteristics of single cylinder,two cylinder and three cylinders in a line is summarized.Then,the interference effects of aerodynamic force and wind pressure distribution of three cylinders in a line are studied by rigid model pressure measurement experiment.The main work of this study is as follows:(1)The aerodynamic characteristics of a single cylinder are studied,and the reliability of the experimental results is verified by comparing the experimental results of a single cylinder with the experimenting ones.(2)Aerodynamic and wind pressure distributions of 12 spacing ratios of three cylinders in a line in a tendam(wind direction angle is 0°),oblique(wind direction angle is 45°)and side-by-side(wind direction angle is 90°)are studied by using rigid model pressure experiment.It is found that there is a critical spacing ratio of three cylinders in a tendam,whose critical spacing ratio is 3.0≤L/D≤3.5(L is the distance between the centers of two cylinders and D is the diameter of the cylinder);When L/D=1.2,the three side-by-side cylinders appear bistability.(3)The experimental results of three cylinder in a line aerodynamic force were compared with those of single cylinder aerodynamic force,and the disturbance laws of mean drag,mean lift,fluctuating drag and fluctuating lift of three cylinder in a line under different spacing ratios and different wind direction angles are revealed.(4)The experimental results of the wind pressure distribution of three cylinders in a line are compared with those of a single cylinder,and the disturbance laws of the mean and fluctuating wind pressures of three cylinders in a line at different spacing ratios and different wind direction angles are revealed.