澳门银河赌场注册送38-澳门银河赌场招人好招吗_百家乐德州_全讯网下载 (中国)·官方网站

Abstract: Large vertical pipes are key structures connecting subsea wells to offshore platforms. However, existing studies mainly focus on small vertical pipes. In a vertical acrylic pipe with 80?mm inner diameter and 11?m height, a high-speed camera was used to visually research the influences of pipe diameters, liquid properties and inlet effect on air-water co-flow characteristic. Different flow regime maps of vertical pipes (diameters are in the range of 50–189?mm) were compared and the critical gas velocity of the transition boundary from bubble to slug flow tended to increase with the increase of diameters at D?≥?80?mm. Drift-flux models were established in different flow regimes and liquid properties have a significant effect on drift coefficients of bubble flow and slug flow (void fraction α?≤?0.4). The influence of inlet turbulent effect on the gas-liquid interface distribution gradually weakened and disappeared from the pipe base to 85D, where the flow was fully developed. Slug frequency has a trend of increase first and then decrease with the gas Weber numbers increasing at low liquid superficial velocities (JL?≤?0.31?m/s). And on the basis of this law, a new slug frequency correlation was proposed. It was found that there was an exponential relationship between the ratio of lengths of Taylor bubble to slug and the void fraction.