Presentation
Flume Studies of Movement of Crude and Diesel Oil Under Ice
SessionArctic Response
DescriptionMelting sea ice has resulted in more shipping vessel traffic along Arctic sea routes, increasing the probability of fuel spills. Modeling of oil and ice interactions, essential to predicting trajectories, requires characterization of the movement of oil under ice. An experimental design for determining the movement of oil under ice was developed at the Coastal Response Research Center (CRRC) in concert with its partner, NOAA’s Office of Response and Restoration (ORR). An insulated recirculating flume and a series of chillers are used to bring the water temperature to 4°C to simulate Arctic conditions. Two ice blocks are made using aluminum molds that conform to the dimensions of the flume. The first block has a flat bottom surface which creates uniform flow under the ice before reaching the second block containing an ellipse half-cylinder cavity with a 2:1 width-to-height ratio. Chilled oil is injected into the cavity. The behavior of the oil is observed as the velocity of the water flowing under the ice is increased incrementally from 0.0 to 0.65 fps (0.0 to 0.39 knots). The experimental variables are type of oil (marine diesel and crude oil) and under-ice water velocity. The volume of oil stored in the cavity and oil movement along the underside of the ice are monitored using GoPro cameras. Oils evaluated include fresh HOOPS crude oil and marine diesel which experience initial movement out of the cavity at 0.48 ± 0.015 fps (0.29 ± 0.009 knots) and 0.52 ± 0.007 fps (0.31 ± 0.004 knots), respectively. On one of the runs with marine diesel, gelling occurred causing a phase separation, with “waxy strands” close to the interface with the ice and liquid in contact with the water. For oil and marine diesel, the liquid in the cavity first forms ripples, then fingers that extend out of the cavity and retract back into it. Finally, when it reaches a threshold, the liquid forms droplets and bean-shaped pods that break off from the mass and move along the undersurface of the ice. Determining the flow regime under which oil leaves the cavity will help modelers estimate the potential for the transport of oil under ice.
Authors
UNH Director, Coastal Response Research Center
Event Type
Paper
TimeWednesday, May 15th2:50pm - 2:51pm CDT
Location275-277
Response