Abstract

Liquid Crystal Imaging of Flow Boiling in Minichannels

Quantitative liquid crystal thermography was used to investigate boiling incipience and nucleate flow boiling in rectangular mini-channels with channel heights of 2 mm to 500 mm. Distributions of surface temperature along the heated surface were measured from the liquid crystal images, and streamwise profiles of heat transfer coefficient on the heated surface were calculated. The working fluid was the refrigerant R-11. Observations of the boiling incipience superheat excursion, the hysteresis phenomenon, and saturated flow boiling are presented. Comparisons to established two-phase heat transfer correlations are performed to investigate the existence of "thin channel" effects.

Brief Bio

Keith Hollingsworth is Associate Professor of Mechanical Engineering at the University of Houston. He joined the faculty in Houston after receiving his Ph.D. from Stanford University in 1989. Professor Hollingsworth is involved in research in several areas of thermal science including turbulent fluid mechanics and convective heat transfer, boiling heat transfer, and liquid crystal imaging of complex temperature fields. He has advised or co-advised over 25 theses and dissertations.