Laboratory Investigation of Trash Rack Freezeup by Frazil Ice

• Main Authors: Andersson, Annika, Daly, Steven F.
• Other Authors: COLD REGIONS RESEARCH AND ENGINEERING LAB HANOVER NH
• Format: Text
• Language: English
• Published: 1992
• Subjects: Snow; Ice and Permafrost; *ICE FORMATION; VELOCITY; TEMPERATURE; MODELS; POROSITY; ICE; FLOW; BLOCKING; ACCUMULATION; WATER FILTERS; BRIDGES; MEAN; RODS; PATTERNS; SURFACES; WATER; FACILITIES; SHAPE; *FRAZIL ICE; *TRASH RACKS; Ice; permafrost
• Online Access: http://www.dtic.mil/docs/citations/ADA258120; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=ADA258120

A series of tests was conducted in a refrigerated flume facility to determine the ice accumulation pattern on models of water intake trash racks. Data gathered included the flow velocity, the water temperature and the porosity of the accumulated frazil ice (mean porosity is 0.67). Frazil accumulates first on the upstream face of the trash rack bars (being insensitive to bar shape), and then bridges between individual bars near the water surface, proceeding downward until the entire trash rack is blocked. Flow through the rack became highly nonuniform during the accumulation process.