The Camera-Observed and Instrumented Loop (COIL) Facility uses a high speed camera and pressure transducers to analyze cross-flow induced vibrations of a test element over a range of flow regimes.  A clear glass cylinder allows for visual access to the element under analysis and an angled mirror provides a simultaneous second view for three-dimensional reconstruction. The initial test element is an aluminum wire wound into a helical coil and attached to an inner cylinder. Piping connects the test section to a fluid reservoir with flow provided by a circulating pump. Flow control meters provide manual control of flow rate. Pressure transducers, before and after the test section, meter gauge and differential pressure across the helical coil.

The purpose of this facility is to fully characterize the motion of a helical coil over a range of flow rates. This will provide insight into how steady flow affects flexible structural elements under similar conditions. A similar geometry is found in current integral Pressurized Water Reactor (iPWR) steam generators. It will also provide empirical data on the pressure drop across a coil under fluid flow when suspended in an annulus.

Flow in this facility has a range between 0.4 and 14 gpm with a fine adjustment resolution of 0.2 gpm. Internal gauge pressure in the test section varies based on the flow conditions, ranging from 0.0 to 12 psig.  Pressure drop across the test section can be detected with 0.015 psig accuracy.  Adjustment of camera placement gives a range of pixel resolution, from 0.002 to 0.006 inches per pixel.

COIL facility with labeled parts

The COIL facility.


Image of structure (left) and correlated geometry (right)
Image of structure (left) and correlated geometry (right).