The Ice Engineering Facility Flume at CRREL is a 2 × 4 × 120 ft long refrigerated, tilting bed structure that constantly re-circulates water and can be used to model a wide range of basic and applied research problems involving ice and river environments.  Previous activities in the Flume include the following:

• Investigating the fundamental properties of frazil ice formation, evolution and accumulation
• Investigating frazil ice blockage of water intake trash racks
• Determining the effects of ice covers on sediment transport and scour
• Investigating the effects of frazil ice on fish respiratory systems
• Quantifying the relationship between waves and the ice formation process
• Determining heat transfer between ice cover and moving water
• Modeling snowdrifts in an urban area by using sediment as a medium
• Determining the effects of oil spills in river environments by using sand, gravel and cobble beds

Success Stories

There has been recent national interest related to diluted bitumen products produced from Canadian tar sand deposits and the potential environmental impacts to areas that would be traversed by a potential pipeline across North America.  One of the major discussion points requiring further research surrounded the anticipated behavior of these oil products both within pipelines and once spilled in fresh water environments.  Using the Ice Engineering Facility Flume, CRREL researchers investigated the behavior of these diluted bitumen and crude oil products by simulating spills in and around a variety of simulated river environments. 

This project served as a successful first step in comparing the physical and chemical properties and general spill fate, behavior and movement of diluted bitumen products presently being transported in North America with those of conventional heavy crude oils that have been transported throughout North American over the past 20 years. The Flume modeling capability served as a cost-efficient, effective method to quantify these environmental impacts over time; to understand materiel properties and complex interactions as the petroleum weathered in the environment; and to inform stakeholders of potential second-order impacts of spills in river environments.

Features

Flume

• 120 ft long by 4 ft wide and 2 ft high glass side panels
• Tilting bed from +1° to –2° slope
• Recirculating sediment
• Super-cooling ramp to cool water before it enters the flume, increasing the usable length of the flume for frazil ice studies
• Recirculating glycol in the bed to refrigerate or to heat the bed
• Heated louver gates and adjustable weir at the tailbox or downstream end of the flume to control the water level

Wave Maker

• Paddle type for regular waves

Carriages

• X-Y-Z computed control instrumentation carriage: A rack and pinion drive moves the carriage the length (x axis) of the Flume with 2 mm accuracy.  Two separate lead screws on the front edge of the carriage are used to position the instrument across the flow (y axis) or through the water column (z axis). The carriage has two modes of operation: discrete and continuous. In discrete mode, the carriage moves to position and is stationary while a measurement is made (for example, water velocity). In continuous mode, data is being collected as the carriage moves. A “no fly zone” can be designated to prevent instrumentation from hitting an obstruction in the flume (i.e., a weir, the model structure, etc.). The carriage has 120 VAC, an internet connection onboard via festoon, and a 20 lb payload capacity for instrumentation.
• Work platform: This is a robust carriage designed for instrumentation that would be manually positioned before taking data. For the sediment work, a bed level system is attached to this carriage.

Refrigeration

• Air
  • The recirculated ammonia refrigeration system can refrigerate the room to –15°F (–26°C) by using two zones or eight air units.
  • It is computer controlled with archiving of 15 minute data to document freezing environment.
  • There is a continuous operation of air units with hot gas defrost when air unit efficiency falls below an acceptable level due to icing.
• Water
  • An Ice Builder Coil submerged in the 6200 gal. pump reservoir maintains the water temperature at the freezing point independent of the ambient temperature in the cold room.
• Flume Bed
  • Chilled glycol can be circulated in the flume bed and freeze the bed of the flume.

Recirculation Pumps

• P16, 1850 gpm (0.12 m3/s) with closed loop feedback system, including frequency drive on the pump, and a Fisher Porter NIST traceable magnetic flow meter with 1/4 % accuracy. Pump is rubber-lined to recirculate sediment. Inline heat exchanger can be used to heat the water.
• P17, 4000gpm (0.25 m3/s) rubber-lined pump for sediment, which is currently configured as constant discharge with flow regulated using by-pass valves.

Water Management

• Water drawn from a reservoir in the basement of the facility is cooled using submerged refrigeration coils or heated using an inline shell and tube heat exchanger. The reservoir has two sections (i.e., settling tank and suction sump). Water returning from the flume can cascade over the ice builder coil or return to pump suction by positioning a flapper gate.
• Air bubblers agitate the water in the reservoir to keep the sediment in suspension and to ensure that the water is isothermal.
• Sand filtration system maintains the water quality; if required, additional filtration can be done using cartridge filter.

Miscellaneous

•  Monorail with 2.5 ton (22.2 kN) crane on the center line of the flume
• Wind current generated by two independent fans resting on rails

Instrumentation

• Thermistors for temperature measurement
• Laser for bed profiling
• Pressure sensors for monitoring water levels and waves
•  Sontek acoustic Doppler velocimeter capable of measuring both the mean flow and turbulence in three directions

Data Acquisition Systems

• Hart Scientific high-resolution temperature sensing system
  •  0.001°C (0.01°C accuracy), 10 channels
  • 2 SPRTs NBS traceable
  • Calibration by comparison method for up to 8 thermistors
•  Lab View high-resolution multi-function I/O
  • 16 bit 100 Khz A/D, 16 SE or 8 Diff channels
  • Programmable gain 1, 2, 5, 10, 20, 50, 100
  • 2 ANA output channels +/– 10 Vdc, or 0–10 Vdc
  • 8 I/O channels TTL compatible
  • 4 slot expander chassis to increase channel density with MUX
  • Signal conditioning for RTDs, thermistors, millivolt.

Using the Test Basin

Our capabilities and facilities are available to assist you in addressing and solving a variety of cold regions science and engineering challenges.  Please consult the facility manager below for facility usage and rate information, which varies depending on the type of activity and support needed.  The facility manager can also provide additional technical documentation on the Flume and supporting equipment and other recent success stories.

Contact

Marina.Reilly-Collette@usace.army.mil, 603.646.4130

Research Mechanical Engineer

Engineering Resources Branch (CEERD-RZE)

US Army Engineer Research and Development Center | Cold Regions Research and Engineering Laboratory