Abstract
Annular flow experiments in horizontal flow in pipes were conducted with emphasis on wave characteristics (wave velocity, wave frequency) and liquid film thickness. The experiments were conducted using water/air in a 0.0504m pipe diameter with a total flow loop length of 28.68m. Liquid film thickness in all the flow matrix in this study, were observed to be decreasing with increase in gas velocity while increasing with increase in liquid velocity. The decreasing tendency with superficial gas velocity was because of liquid entrainments which were accounted. Pan and Hanratty correlation for liquid entrainment was chosen because it gave the most realistic results among other correlations from the experimental data. Wave velocity and wave frequency were presented to be increasing with increase in superficial gas velocity in annular flow. For wave frequency, it was observed that both superficial liquid and gas velocities have great impact on it. In annular flow in horizontal pipe, it was also observed that the lower the superficial liquid velocity, the lower the amplitude and the higher the wave frequency. This indicates that at low liquid velocity, more ripple waves occurred and at this time more energy were dissipated which resulted to the high frequency observed in this study. However, several correlations where compared with the obtained wave frequency in this study, but [2] preferably matched better as the superficial liquid velocity increases from 0.0903m/s to 0.1851m/s.
Highlights
Annular flow is a complex flow regime, encountered in petroleum production systems, nuclear power plants, chemical and refining processes
There are several scholarly reports on liquid film thickness investigated in annular flow. [3]
The flow loop had 2-pairs of pressure transducers installed at 2.13m apart, light emission diode infrared sensors (LED), two double pairs of conductivity rings sensors installed at 0.07m apart, pairs of conductance probes installed at 0.20m apart and the temperature sensors
Summary
Annular flow is a complex flow regime, encountered in petroleum production systems, nuclear power plants, chemical and refining processes (reactors, heat exchangers). Annular flow in horizontal pipes, flow with high gas velocity at the core center of the pipe with much impact of gravity leaving the circumferential liquid film at the internal walls of the pipe which drains to the bottom of the pipe. Represents a thick liquid film at the bottom that moves slowly on the internal pipe walls than the gas phase [13]. It is characterized by asymmetry distributions, depending on the mass flow rate of the liquid and gas [27]. In evaluating annular flow behaviors in pipes: annular flow characteristics like liquid film thickness, wave characteristics (wave velocity, wave frequency), interfacial friction factor and pressure gradient were investigated.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
