Aliyu, A. M.Almabrok, Almabrok AbushanafBaba, Yahaya D.Lao, LiyunYeung, HoiKim, Kyung Chun2017-01-042017-01-042017-01-02Aliyu AM, Almabrok AA, Baba YD, et al., (2017) Upward gas–liquid two-phase flow after a U-bend in a large-diameter serpentine pipe. International Journal of Heat and Mass Transfer, Volume 108, Part A, May 2017, pp. 784-8000017-9310http://dx.doi.org/10.1016/j.ijheatmasstransfer.2016.12.069http://dspace.lib.cranfield.ac.uk/handle/1826/11209We present an experimental study on the flow behaviour of gas and liquid in the upward section of a vertical pipe system with an internal diameter of 101.6 mm and a serpentine geometry. The experimental matrix consists of superficial gas and liquid velocities in ranges of 0.15–30 m/s and from 0.07 to 1.5 m/s, respectively, which cover bubbly to annular flow. The effects on the flow behaviours downstream of the 180° return bend are significantly reduced when the flow reaches an axial distance of 47 pipe diameters from the U-bend. Therefore, reasonably developed flow is attained at this development length downstream of the bend. Other published measurements for large-diameter film thickness show similar trends with respect to the superficial gas velocity. However, the trends differ from those of small-diameter pipes, with which the film thickness decreases much faster with increasing gas flow. As a result, only a few of the published correlations for small pipe data agreed with the experimental data for large pipe film thickness. We therefore modified one of the best-performing correlations, which produced a better fit. Qualitative and statistical analyses show that the new correlation provides improved predictions for two-phase flow film thickness in large-diameter pipes.enAttribution-NonCommercial-NoDerivatives 4.0 Internationalhttp://creativecommons.org/licenses/by-nc-nd/4.0/Conductance film probesLarge diameter pipesMultiphase flowReturn bendsWire mesh sensorArticle