Experimental investigation on flow patterns and pressure gradient through two pipe diameters in horizontal oil-water flows

The pressure gradient values obtained in the 19 mm pipe are greater than those measured in the 25.4 mm pipe at similar superficial oil and water velocities. The differences in pressure gradient results become bigger with higher oil and water velocities. The experimental pressure gradient results were compared with the two-fluid, homogenous and drift-flux models. The drift-flux model showed a good prediction to the experimental results while the two-fluid and the homogenous models were found to highly overpredict the experimental results especially for the smaller pipe diameter.