The effect of the fluid properties on the wave velocity and wave frequency of gas–liquid annular two-phase flow in a horizontal pipe.

The effects of fluid properties on the wave velocity and frequency of gas–liquid annular two-phase flow were investigated in 26 and 16-mm inner pipe diameters. The liquid viscosity was varied from 1.02 to 6.57 mPa s using water and glycerol solution and the surface tension was varied from 34.0 to 71.7 mN/m using water and butanol solution. The range of superficial liquid and gas velocities were set to 0.05–0.2 m/s and 12–40 m/s, respectively. In general, the wave frequency decreases with increasing liquid viscosity and decreasing surface tension. The wave velocity decreases with increasing liquid viscosity for all range of superficial gas and liquid velocities. The lower surface tension gives the lower wave velocity for low superficial liquid velocity. For high superficial liquid velocity, however, the wave velocity increases with decreasing surface tension. The wave frequency decreases with the increase of liquid viscosity and the decrease of surface tension, with more significant effects are found at the higher superficial gas and liquid velocities. Comparisons of experimental data with the existing correlations for wave velocity and wave frequency have been carried out and new correlations have been developed with a considerably good agreement with the experimental data. [ABSTRACT FROM AUTHOR]