Abstract:

In the wind loads on serial 2-bundled conductors， the drag force of the leeward conductor can be influenced by the vortex shedding of the windward conductor. In order to investigate the wind load shielding effects of serial 2-boundled conductors with the variation of wind velocity and bundle spacing， the overall drag coefficients of three types of model conductors were tested in wind tunnel under different wind velocity and bundle spacing. Meanwhile， the drag coefficient of one type of commercial conductor was tested and compared to examine the accuracy of the model conductor’s simulation to the commercial one. The results show that the simulation by model conductor has high accuracy. The drag coefficients of the lee-ward conductors as well as the global drag coefficients of the 2-boundled conductors grow with the increase of bundle spacing， but they are all much smaller than the value recommended in the current design standards. The global drag coefficients of the 2-boundled conductors decrease at first， and then rise with the increase of wind velocity; however， they are all much smaller than that of a single conductor in all wind velocity. The recommended value of the global drag coefficient of the multi-bundled conductors in the current design standard is on the high side and can be reduced by taking the shielding effect into consideration.

Key words: serial 2-bundled conductors, drag coefficients, shielding effect, bundle spacing, model conductor, commercial conductor