MIR Flow System
The system is a closed-loop flow system. It is fabricated from stainless steel with a polycarbonate test section. The test section has three separate chambers; each constructed of 3.8 cm (1.5 in) thick optical-grade polycarbonate. The test section is 0.61 m x 0.61 m x 2.44 m (24 in x 24 in x 8 ft). Each of the three individual chambers is fitted with a removable lid that allows for open channel flow or tunnel/duct flow when the lids are in place and the facility is completely filled with fluid. Each chamber is equipped with high quality glass windows on each side of the test section to accommodate optical measurement devises. The large size of the test section offers outstanding spatial and temporal resolution and provides a means to measure velocity and turbulence fields in and around complex geometries without disturbing the flow with a sensor or probe. Optical devises are mounted on a 3-directional traverse system that is controlled by three separate electric stepping motors. This traverse system can position and re-positioned the measurement devices to within 2 m accuracy.
During normal operations, the system contains approximately 2750 gallons of light mineral oil as the working fluid. The fluid is circulated by an axial flow pump powered by a 56 kW (75-hp) variable speed electric motor that can provide a maximum volumetric flow rate of approximately 0.63 m3/s (approximately 10,000 gpm) of fluid through the test section. This volumetric flow rate corresponds to a maximum velocity of approximately 1.7 m/s at the inlet of the test section. Both laminar to fully turbulent flows can be attained in the test section. Flow conditioners located upstream of the test section inlet establish uniform cross-sectional velocity profiles with turbulence intensities below 0.5%. A turbulence generator can be installed upstream of the test section which can produce 3-D turbulence intensities of 12-13%.
The facility is equipped with a vibration-isolation system which can support the entire system on a cushion of air. This air suspension system can isolate the test section from the vibrations caused by system pumps and the facility environment.