Making Frazil Ice in a Large Ice Tank

The paper describes a series of laboratory experiments on frazil ice formation in a large body of water, and on subsequent frazil-ice congestion of a water intake located at the bottom of the water body. The experiments sought insights and data regarding flow-field influence on frazil ice formation and ingestion by such an intake. They were conducted using a refrigerated ice-tank at IIHR-Hydroscience and Engineering. The flow field around the bottom intake was monitored using particle image velocimetry. The tank approximately simulated the typical conditions for submerged intakes located in large water bodies. The conditions included wind-induced waves. The experiments are very unusual, insofar that they were conducted at such a large scale. Commensurately, they were not without their challenges; the major ones being to super-cool a large body of water, and to produce frazil ice in a controllable manner in that water. The super-cooled water body in the tank was 21m long x 5m wide x 0.55m deep (58m3 in volume). After some initial experimental difficulties, it was found that substantial quantities of frazil ice indeed could be formed in a sufficiently controllable and repeatable manner to facilitate experiments on the ingestion of frazil ice by a submerged intake. 1