23 April 2010
Hanover, N.H. — A freelance film crew working for Discovery Channel visited the ERDC Cold Regions Research and Engineering Laboratory (CRREL) recently to record and interview Research Civil Engineer Leonard Zabilansky regarding the natural ice phenomena, ice circles.
“We are making a new documentary series for the Discovery Channel that examines the science behind unusual phenomena,” stated science producer, Chris Young, Cineflix Productions. “One of the stories that we are doing is about unusually perfect, often spinning, ice circles that have been found to occur around the world in river and lakes. There are several plausible theories for how they might form, and I am looking for a testing facility that would be willing to work with us to perform some experiments to see if we could solve the mystery through science.”
To replicate the natural setting, a 40-feet-long-by-16-feet-wide race track flume was constructed in CRREL’s Research Area and the room temperature was controlled at around 17 degrees Fahrenheit to simulate the natural environment conducive to ice circle development.
“This was certainly a challenge put before us,” said Zabilansky. “In a river system, ground water inflow tempers the water, reducing the likelihood of frazil ice production and limiting the formation of an ice circle to ice floating on the surface. In a laboratory setting, we cannot exactly duplicate Mother Nature’s processes, but we can try.”
Concrete blocks were used to create the 4-foot-wide channel and 7-foot-diameter eddy pool where the ice circle would form. Three pumps were used to recirculate the water within the race track flume at 1.5 to 2 feet per minute. To simulate the thermal characteristic of the ice capturing ice circles in nature, the eddy pool’s perimeter was lined with plastic.
Researchers were able to create the conditions and duplicate the process in which ice circles could form in a cold room environment. To the best of our knowledge, this process has not been modeled in a controlled environment before now, and both researcher and facility were successful in reproducing ice circles.
“Modeling ice circles in the race track flume was a delicate balance between hydraulics (the water’s 3-D velocity profiles), frazil and slush ice concentrations, and air temperature,” said Zabilansky. “It is exciting that we were able to create the conditions and duplicate the process in the cold room environment.”