Investigation of the hydraulic effects of ice booms

Abstract

The hydraulic effects of ice booms were investigated in a series of small-scale experiments. Ice booms were modeled as single cylinders partially submerged at the surface of an open-water channel. Pertinent boom specifications were considered in the selection of test conditions. Three tests were performed with a Froude number (based on approach flow depth) of 0.11 and submergence levels ranging from 30% – 70%. An additional nine tests were completed for Froude numbers (based on cylinder diameter) ranging from 0.13 – 0.65, Reynolds numbers (based on cylinder diameter) ranging from 2882 – 25509, and a submergence level of 50%. Measurements from planar particle image velocimetry enabled the assessment of flow characteristics, including streamline topology, vorticity, periodicity, mean velocities, Reynolds stresses, and triple velocity correlations. In each test, a separation bubble was present downstream of the model. The structure of the bubble depended on the submergence level, Reynolds number, and Froude number. Vorticity was elevated near the model, although distributions were relatively unaffected by the submergence level. Some localized vortex shedding was observed, but the surrounding flow lacked strong periodicity. In the surrounding flow, extreme values of mean velocities typically shared strong relationships with Reynolds number. Reynolds stresses were elevated throughout the wake. Within the wake, maximum values of most Reynolds stresses lacked meaningful relationships with both Reynolds and Froude number. Distributions of triple velocity correlations showed that the turbulence produced was mostly transported into the wake. Overall, this study provides exciting new insights into the impact ice booms have on the surrounding flow.