Rainwater rivulets on a cable subject to wind

Cécile Lemaitre (1) , M. Mahmud Alam (2) , Pascal Hémon (1) , Emmanuel de Langre (1) , Y. Zhou (2)

1 LadHyX - Laboratoire d'hydrodynamique
2 Department of Mechanical Engineering [Hong Kong]

Rainwater rivulets appear on inclined cables of cable-stayed bridges when wind and rain occur simultaneously. In a restricted range of parameters this is known to cause vibrations of high amplitudes on the cable. The mechanism underlying this effect is still under debate but the role of rainwater rivulets is certain. We use a standard lubrication model to analyse the dynamics of a water film on a cylinder under the effect of gravity and wind load. A simple criterion is then proposed for the appearance and position of rivulets, where the Froude number is the control parameter. Experiments with several geometries of cylinder covered with water in a wind tunnel show the evolution of the rivulets with the Froude number. Comparison of the prediction by the model with these experimental data shows that the main mechanism of rivulet formation and positioning is captured. © 2006 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]

Cécile Lemaitre, M. Mahmud Alam, Pascal Hémon, Emmanuel de Langre, Y. Zhou. Rainwater rivulets on a cable subject to wind. Comptes Rendus Mécanique, 2006, 334 (3), pp.158-163. ⟨10.1016/j.crme.2006.01.005⟩. ⟨hal-01023367⟩