A MODEL FOR THE NUMERICAL SIMULATION OF RIVULET EVOLUTION ON A CIRCULAR CYLINDER IN AN AIR FLOW

The simultaneous occurrence of rain and wind can generate rivulets of water on the cables of cable-stayed bridges. Under certain conditions the interaction of these rivulets with the local aerodynamic field may result in Rain Wind Induced Vibration (RWIV). A method to model this phenomenon computationally is currently under development at the University of Strathclyde. The current paper presents a two-dimensional model for the evolution of a thin film of water on the outer surface of a circular cylinder subject to pressure, shear, surface-tension and gravitational forces. Numerical simulations of the resulting evolution equation using a bespoke pseudo-spectral solver capture the formation of 'rivulets'; the geometry, location and growth rate of which are all in good agreement with previous studies.