The effect of pipe diameter on the structure of gas/liquid flow in vertical pipes

Flow Patterns, Void Fraction and Pressure Drop in Gas-Liquid Two Phase Flow at Different Pipe Orientations

“…The effect of pipe diameter is observed to vanish gradually with increase in the two phase flow quality. This observation is in agreement with the work of [55] who investigated the effect of pipe diameter in a range of 5 mm \ D \ 50 mm on void fraction in vertical upward annular flow regime for non-boiling two phase flow. They found that the effect of pipe diameter on void fraction in the annular flow regime is negligible.…”

“…4.17, it is clear that for horizontal two phase flow at fixed mass flow rate of R134a, the two phase frictional pressure drop for different pipe diameters deviates significantly for large values of flow quality (annular flow regime) whereas, for low mass qualities, the pipe diameter has little effect on two phase frictional pressure drop. Similar conclusions were drawn from the work of [55] who compared the two phase frictional pressure drop of air-water in vertical upward flow for pipe diameters in a range of 10 mm \ D \ 50 mm. As mentioned earlier, the frictional pressure drop is due to the friction at pipe wall and friction at gas-liquid interface.…”

“…However, based on the trend of the data in Fig. 4.13 for horizontal two phase flow and the results of [55] for vertical upward flow, it can be conjectured that the effect of pipe diameter on void fraction is independent of the pipe orientation for annular flow regimes. More experimental data and in-depth analysis is required to verify this effect for other flow patterns.…”

Disturbance wave development in two-phase gas–liquid upwards vertical annular flow

“…The latter waves were always found to occur on the back-slopes of the former and catch up with them under entrainment conditions; this no longer occurs in noentrainment conditions. Schubring et al (2010bSchubring et al ( , 2010c) also used PLIF to visualise the liquid film in vertical, upwards annular flow, and to show that its average thickness increases with liquid flow-rate and decreases with gas flow-rate, while Kaji and Azzopardi (2010) examined the formation of disturbance waves in upward annular flow and showed that their speeds can be predicted successfully using existing correlations at low liquid flow-rates only.…”

Gas‐water energy conversion efficiency in two‐phase vertical downflow

“…Most of these studies focused on small diameters less than 100 mm, with the exception of Almabrok et al [24], who conducted an experimental study on gas-water flow behaviors in a vertical pipe with a diameter of 101.6 mm. Kaji and Azzopardi [25] investigated the effect of the pipe diameter on the flow characteristics of a two-phase flow. The pipes tested in this work have diameters of 160, 200, and 250 mm, which are considerably larger than those tested in previous studies.…”