Study On The Of Three-Dimensional Aerodynamic Admittances Of Rectangular Cylinder Based On Active-Passive Hybrid Wind Tunnel Tests

Based on classic spectral tensor theory of turbulence and three-dimensional buffeting theory,a method of identifying the three-dimensional aerodynamic admittance of blunt body cross-section at angles of wind attack has been put forward.Based on the proposed method,the equivalent three-dimensional aerodynamic admittance of 5:1rectangular section considering the influence of wind angle of attack is identified by passive wind tunnel pressure test.Then by using active and passive wind tunnel test methods,the identification theory of u and w separated two-dimensional aerodynamic admittance of rectangular section are obtained.In this dissertation,the main research contents include the following four points:1.The buffeting analysis methods and aerodynamic admittance identification methods of bridge structure are summarized.The characteristics and defects of the aerodynamic admittance identification methods of bluff body section are concluded.2.Based on the theory of three-dimensional spectral tensor analysis,the identification framework of three-dimensional aerodynamic admittance theory of rectangular section under non-zero angle of attack is established.The closed expression of three-dimensional aerodynamic admittance of rectangular section is put forward by using the pressure test of passive wind tunnel,and the influence mechanism of u and w pulsation components on buffeting lift of rectangular section under different wind attack angles is revealed.3.Based on the active control wind tunnel technology,an active wind tunnel simulation method of longitudinal continuous turbulence is proposed.A theoretical identification framework of three-dimensional aerodynamic admittance of rectangular section under the action of longitudinal turbulence is established,and a closed expression of three-dimensional aerodynamic admittance is proposed.4.Based on the active and passive hybrid wind tunnel test method,a theoretical identification method ofu and wseparated two-dimensional aerodynamic admittance is proposed,which provides a solid theoretical basis for the accurate evaluation of buffeting load of blunt body section in practical engineering.