Design of a hot-film probe calibrator, calibration of UTSI water tunnel, and flow visualization study of secondary flow in a laminar corner

The purpose of this study was the experimental investigation of secondary flow in a 90° comer for laminar flow in the test section of The University of Tennessee Space Institute (UTSI) water tunnel. A hot-film calibrator for velocities from 0.2 to 20 in/sec was designed and used to calibrate a TSI Model 1210-20W cylindrical quartz coated hot-film water probe. The hot-film probe was placed upstream of the test section and speed and turbulence level in the tunnel were measured.

Flow visualization techniques such as hydrogen bubbles and dye injection were used to search for the embedded vortices in the comer model. The major finding of this investigation was that, within the limitation of detection techniques employed, no vortices were found.