No abstract

An investigation on flow pattern, pressure drop, and holdup of cocurrent upward two-phase flow in a vertical helical coil tube has been carried out with Newtonian and non-Newtonian fluids. The flow patterns observed in the present study are divided into three main regimes, i.e. plug flow, slug flow, and stratified flow. Lockhart-Martinelli parameter (X) was used to predict the friction factor and frictional pressure drop of two-phase flow. Correlations for the frictional pressure drop were developed to interpret the observed flow patterns with various operating variables. The effect of geometrical parameters on flow pattern, pressure drop, and holdup are enunciated. Based on the experimental data, a correlation was proposed to predict the flow transitions of flow patterns (i.e. plug-slug flow and slug-stratified flow) by dimensional analysis. Probabilistic neural network model has also been developed to predict the flow patterns of two-phase flow. Figure 5. Effect of coil diameter (D c ) on flow regime of non-Newtonian fluids at constant tube diameter d t = 0.015 m, SCMC concentration = 1.0 kg/m 3 and pitch difference (p/D c ) = 1.0. Asia-Pacific Journal of Chemical Engineering FLOW PATTERNS OF GAS NON-NEWTONIAN FLUID FLOW 429 R 2 , correlation coefficient; SE, standard error.Figure 11. Effect of different variables [(a) superficial liquid velocity at d t = 0.02 m; D c = 0.2 m; P/D c = 1.0; SCMC-1.5 kg/m 3 , (b) coil diameter at d t = 0.02 m; P/D c = 0.5; Usl = 1.238 m/s; SCMC-3.0 kg/m 3 , (c) tube diameter at D c = 0.075 m; P/D c = 1.0; SCMC-3.0kg/m 3 and (d) pitch difference at d t = 0.15 m; D c = 0.117 m; SCMC-3.0 kg/m 3 ] on frictional pressure drop.

No abstract

No abstract