A laser induced diagnostic technique for velocity measurements using liquid crystal thermography

Abstract

Wind tunnel experiments were performed to show that wind velocity could be correlated to thermal patterns generated on a model surface. The idea makes use of the thermal patterns generated by a laser thermal tuft that was originally developed and patented (Patent #5,963,292) by researchers at the USAF Academy and the University of California, Davis. The present study quantifies this flow visualization idea by correlating the length of the thermal tuft to velocity and demonstrates that this measurement is strongly dependent on laser power. Until now, the laser thermal tuft has been used only to qualitatively characterize flow fields. By quantifying flow velocity, this extension of the patented idea may promote increased usage of this laser thermal tuft technique.