Analysis of Void Fraction Phase Distribution of Gas-Liquid Flow In a Horizontal Pipe Using Wire Mesh Sensor Data

Inkum, Henry (2014-12-15)


The scope of this work was to make detailed analysis of phase distribution in a horizontal pipe. This detailed analysis has been successfully carried out. Data obtained from wire mesh sensor (WMS) were used for the analyses. The operating fluid considered was an air/silicone oil mixture within a 6 m horizontal pipe with internal diameter of 0.067 m. The gas superficial velocities considered spans from 0.047 to 4.727 m/s, whilst liquid superficial velocities ranged from 0.047 to 0.4727 m/s. The wire mesh sensor (WMS) data obtained consist of the average cross- sectional and time average radial void fraction sensor with an acquisition frequency of 1000 Hz over an interval of 60 s. For the range of flow conditions studied, the average void fraction was observed to vary between 0.38 and 0.85. An analysis of the results shows that the major flow patterns observed in this study were found to be in slug and smooth stratified flow regime with the slug flow been the dominant one. At constant liquid superficial velocity, the void fraction increases with an increase in the gas superficial velocity. This observed trend in the horizontal void fraction is consistent with the observations made by (Abdulkadir et al., 2014) and (Abdulkadir et al., 2010) which were all in the vertical orientation. The performance of the void fraction correlations and their accuracies were judged in terms of percentage error and RMS error. Nicklin et al. (1962), Hassan (1995) and Kokal and Stanislav (1989) were judged as the best performing correlations and Greskovich and Cooper (1975)as the least. A cubic profile which was dependent on the gas superficial velocity was observed as the radial void fraction increases with gas superficial velocity. It was also obseved that for a given liquid superficial velocity, the frictional pressure drop increases with increase in both gas and mixture superficial velocities. Another finding made was that, even though Wu et al. (2001)’s model was proposed for vertical orientation with air and water used as the operating fluid, it could as well replicate the observed radial void fraction in the horizontal orientation. The experimental frequency was seen to increase with liquid superficial velocity but followed a sinusoidal trend with increase in gas superficial velocity.