An experimental investigation of the effects of gas solubility on the properties of horizontal slug flow

The present work investigates the effects of gas solubility on the fluid dynamic properties of a horizontal two-phase slug flow. Measurements of the size distributions of the liquid slug and of the long bubbles are provided, as well as local measurements of the liquid velocity in the slug, the velocity in the liquid film, the velocity of propagation of the nose of the long bubbles and the pressure drop. These parameters were obtained through two optical techniques: Shadow Sizer (SS) and Particle Image Velocimetry (PIV). The experiments indicate that the solubility has a substantial influence on the flow properties resulting, in particular, in a significant reduction of the local pressure gradient over a relatively short distance (8 m). The data are compared with modified versions of the mechanistic models of Dukler and Hubbard (Dukler, A.E., Hubbard, M., 1975, A model for gas–liquid slug flow in horizontal and near horizontal tubes, Ind. Eng. Chem. Fund. 14(4), 337–347) and of Orell (Orell, A., 2005, Experimental validation of a simple model for gas–liquid slug flow in horizontal pipes, Chem. Eng. Sci. 60, 1371–1381) so that the solubility effects can be taken into account.Indisponível

Turbulence and Bubble Break up in Slug Flow with Wall Injection

The present work investigates experimentally the changes on the properties of horizontal slug flows subject to fluid injection at the wall. Measurements include data on global flow rates, pressure drop and local mean and fluctuating velocity profiles for nine different conditions. The properties of the two-phase flow are measured through a Shadow Sizer system and laser-based sensors. Two distinct flow transpiration rates are studied, v++wi = v w / U m = 0.0005 and 0.001. The effects of flow transpiration were observed to induce bubble break-up and large changes in the passage frequency and characteristic lengths of the unit cells. In addition to the two-phase flow results, single-phase flow measurements are presented with a view to compare the different turbulent effects introduced by the second phase. The work also proposes modifications in the models of Dukler and Hubbard (Ind. Eng. Chem. Fund. 14 337–347 (1975)) and Orell (Chem. Eng. Sci. 60 1371–1381 (2005)) so that fluid injection at the wall can be accounted for. All theoretical predictions are compared with the experimental data.Indisponível