Experimental Heat Transfer for Gas-Liquid Vertical Flow inside Pipe

Abstract

Experiments have been performed to observe flow pattern and investigate convective heat transfer for air-water vertical flow in a forced circulation system. The bubbles motion was recorded by a high-speed CCD camera. For the bubble and slug flow pattern, the temperature fluctuation signals and local heat transfer coefficients were obtained in a short heated tube. The probability density function classical was applied to analyze the temperature. The results qualitatively reflected characteristics of local heat transfer in two phase flow comparing with that in single-phase liquid. The comparison revealed that the gas phase could enhance the heat transfer.

Effects of the gap size on the flow pattern maps in a mini-gap annular channel

“…Undoubtedly, knowing the flow patterns is necessary for designing a thermal engineering system, because the flow patterns affect the system's pressure loss and heat transfer rate. A considerable number of studies about two-phase liquid-gas flow in pipes have been performed [2][3][4][5][6][7]. However, there are relatively few studies about two-phase flow in an annulus.…”