The NRC’s frazil ice research facility is a unique new facility that can generate frazil ice events in a large, controlled and well-instrumented testing environment. Frazil ice consist of ice crystals that form in turbulent and supercooled water. This is an important research area for cold countries like Canada because frazil ice is notorious for clogging water intakes of municipal plants, hydropower and nuclear facilities, and ships. Frazil ice is also well known for contributing to ice flooding events, which can cause millions of dollars in property damage. By studying frazil ice and its impact, our researchers are able to develop innovative engineering solutions to address these challenges.
The testing environment of the NRC’s frazil ice facility in St. John’s, Newfoundland and Labrador, involves a looping water tank, known as a flume, that looks like a speed skating track–a long oval with straight sides.
With a total recirculating volume of around 800 cubic metres, the flume is 36 metres long and 12 metres wide, with an enclosed centre island that is 30 metres by 6 metres. The center line along the full circuit is 88 metres in length. The channel between the outer wall of the water column and the inner island is 3 metres wide. The depth is 3 metres at the deepest point. The facility has been designed to allow water to be circulated at speeds of up to 1.5 metres per second, using 4 electric thrusters.
The air temperature in the facility can be cooled to -20 °C, and 6 wind fans on one side make it possible to generate winds up to approximately 55 km/h over that section of the flume. The water can be cooled at a maximum rate of around 0.07 °C per hour.
The facility allows the water temperature to be chilled to supercooling levels (i.e. below the freezing point), which is a key condition required for the formation of frazil ice. The water temperature is measured using 12 high-precision thermistors (located at 1 and 2 metres deep) and 6 resistance temperature detector sensors.
Turbulence in the water column is generated by the current and, at the surface, by the wind field. Side-looking and upward-looking acoustic doppler current profilers are used for measuring water velocity. Technologists use a manual sampling apparatus to sample frazil ice and estimate ice concentration in the water column. Acoustic doppler velocimetry is also used to gather high-frequency single-point measurements of water velocity and turbulence intensity. 2 high definition underwater cameras and a number of surface cameras provide optical imagery. Researchers at the facility are currently testing an underwater laser scanner for measuring and quantifying frazil accretion on test surfaces. Other sensors, such as hydrostatic pressure sensors, can be deployed and tested.
Why work with us
We work with industry to bridge the gap between innovation and commercialization. The NRC plays a critical role in de-risking and in demonstrating technologies to support industry to bring technologies to market. Working with the NRC offers you the competitive advantage of specialized, customizable testing facilities combined with the broad knowledge and experience of our in-house research staff. The NRC capitalizes on our experts who have extensive experience in advanced engineering for complex water environments.