Experimental Study on Boiling Flow of Liquid Nitrogen in Inclined Tubes—Liquid Slug Length Distribution

An experimental study was carried out to understand the phenomena of the boiling flow of liquid nitrogen in inclined tubes with closed bottom by using the high speed motion analyzer. The tube in the experiment is 1.0 m length and 0.018 m and 0.014 m inner diameter respectively. The range of the inclination angles is 45–90° from the horizontal. The statistical method is employed to analyze the experiment data. The experiment focused on the effect of the inclination angle on the distributions of the liquid slug length along the tube. The experimental results show that the Taylor bubble is easier to coalescence with inclination angle decreasing, but coalescence lessening at 45°. The liquid slug length distributions extend to much larger values for the large tube when x/D is 40 and 50. The mean liquid slug lengths increased first, and then decreased with decreasing θ for two tubes, maximum at 60°.