Transient Velocity Distributions for the Supercritical Carbon Dioxide Forced Convection Heat Transfer

Abstract

The authors successfully visualize the density variation of supercritical carbon dioxide under forced convective heat transfer using schlieren and shadowgraph techniques as research toward the precise characterization of supercritical fluid behavior. Using a new experimental setup with short-pulse infrared laser and high-speed camera and by employing frame straddling, sequential images are obtained at an interval of only 0.48 ms. A noise-reduction step is also added to the cross-correlation algorithm to produce clear and accurate velocity distribution maps. The proposed technique is demonstrated to be a highly effective and accurate analysis tool for the behavior of supercritical fluids, and is expected to be useful in research on precision applications such as nuclear reactors.

KEYWORDS:

• supercritical carbon dioxide
• particle image velocimetry
• infrared pulse laser
• frame straddling
• forced convection