Study On Wind Pressure Distribution And Aerodynamic Interference Of Three Cylinders In Tandem Arrangement

Multiple circular cylinders or square cylinders are common in practical engineering structures,such as chimneys,cooling towers,pylon columns,pier columns and high-rise buildings.Due to small spacing,there exists aerodynamic interference between the groups of cylinders.Compared with the single column,the wind pressure distribution and aerodynamic force of the column group will be different.Tandem multi-column is a common form of column group structure.At present,the study on the interference effect of pressure distribution and aerodynamic force of twin tandem cylinders has been carried out extensively.However,the study on wind pressure distribution and aerodynamic interference of three tandem cylinders has been little so far.At first,research status of the wind pressure distribution and aerodynamic interference effect of tandem multi-circular cylinders and tandem multi-square cylinders were summarized.What's more,wind pressure distribution and aerodynamic interference of three square(circular)cylinders in tandem arrangement were studied.The major contents of the dissertation can be summarized as follows.(1)The wind pressure distribution and aerodynamic force of single circular(square)column and twin circular(square)columns in different spaces were tested by rigid model wind tunnel test.The experimental results were compared with the existing literatures.The test results are reliable.(2)The wind pressure distribution and aerodynamic force of the three circular(square)cylinders in 16 different spaces were tested by rigid model wind tunnel test.The critical spacing of three tandem circular cylinders is 3?(L/D)cr?3.5(L represents the distance between the center of the two cylinders,D represents the diameter of the cylinder),the critical spacing of three tandem square cylinders is 3.5?(L/D)cr?4(L represents the distance between the center of the two columns,and D represents the side length of the square).In the critical spacing range,the wind pressure distribution and aerodynamic force of the three circular(square)cylinders are bistable.(3)By comparion with single circular cylinder,the mean wind pressure coefficient distribution,the variance wind pressure coefficient distribution,the mean value of the drag coefficient and the root of the lift coefficient of three circular cylinders are analyzed deeply.Interference law of pressure distribution and aerodynamic force of three circular cylinders was revealed.(4)By comparion with single square cylinder,the mean wind pressure coefficient distribution,the variance wind pressure coefficient distribution,the mean value of the drag coefficient and the root of the lift coefficient of three square cylinders are analyzed deeply.Interference law of pressure distribution and aerodynamic force of three square cylinders was revealed.