Turbulence intensity on catenary contact wires due to parapets placed on a double track bridge

Abstract

In this paper the experimental results on the turbulence intensity levels at the catenary contact wires due to the presence of parapets placed on the sides of a double track bridge are presented. Both solid and porous parapets are tested, and the influence of angle of attack, parapet height, parapet porosity, bridge deck height, end eave length is also investigated. The turbulence intensity is obtained from measurement of wind speed using hot wire anemometry at bidimensional models placed at the wind tunnel. To show the effect of the several parameters on the experimental data, the results are referred to the turbulence intensity of the bridge without any parapet by defining a reduced turbulence intensity. Experimental results show that, if the parapet wake acts on the catenary contact wire, the turbulence intensity at catenary location grows. Therefore, when angle of attack or parapet height increases, the turbulence intensity at catenary contact wire generally also increases. Addition of eaves to parapets amplifies the influence of the windbreaks on the catenary contact wires. Porous parapets reduce the turbulence intensity at the windward catenary, but deteriorate flow characteristics at the leeward catenary contact wire location.