Wind Loads on High Rise Buildings: an Experimental Investigation on Hexagonal Cylinder

An experimental investigation of surface static pressure distributions on hexagonal cylinder was conducted. The study was performed on both the single cylinder and the group consisting of two cylinders, one in the upstream and another in the downstream side. The test was conducted in an open circuit wind tunnel at a Reynolds number of 41300 based on the face width of the cylinder across the flow direction in a uniform flow of velocity 13.2 m/s. The study was done on the single cylinder at various angles of attack from 0 to 50 degree at a step of 10 degree. The surface pressure distributions were measured with the help of an inclined manometer. Then the group of two cylinders was taken into consideration for the study and the surface static pressures were measured for various interspacing of 1D, 2D, 3D, 4D, 6D & 8D, D being the width of the cylinder across the flow direction. In each case the wind velocity was kept constant at 13.2 m/s. The pressure coefficients were calculated from the measured values of the surface static pressure distributions on the cylinder. Finally the drag and lift coefficients were obtained from the pressure coefficients by the numerical integration method.