Breakup of a drop in a liquid–liquid pipe flow through an orifice

Abstract

in Wiley InterScience (www.interscience.wiley.com).The drop breakup in a heterogeneous turbulent pipe flow developing downstream of an orifice is reported. A two-phase flow is considered of n-heptane drops in a water-glycerin solution at three distinct volume concentrations: f d ¼ 0 (single-phase flow), 0.1, and 0.2. The maximum pressure drop across the orifice, DP max , is found to be a linear function of the kinetic energy of the mixture that weakly depends on f d . The continuous-phase velocity field is measured by means of high-speed particle image velocimetry in an optically homogeneous medium. The turbulence energy level and its spatial distribution are strongly influenced by both the continuous-phase viscosity and the presence of the dispersed phase. Drop breakup is driven by an inertial mechanism and is observed where the turbulence is the most intense. The breakup probability, the mean number of fragments, and the daughter-drop Sauter diameter are plotted against the global Weber number based on DP max . For concentrations up to 0.1, breakup statistics are close to those obtained with an isolated drop in a single-phase flow of water. For f d ¼ 0.2, the increase of breakup probability with the Weber number becomes weaker because of the volume reduction of the region of intense turbulence. The evolution of breakup probability with the distance from the orifice indeed shows strong differences between the test cases, arising from modifications in the local structure of the heterogeneous turbulence field.

Numerical and experimental analysis of particle strain and breakage in turbulent dispersions

“…The turbulence field is well analysed in these investigations, but it is achieved by a jet stream through a nozzle. Similar flow conditions are used in the workgroup of Masbernat (Galinat et al, 2005;Galinat et al, 2007) for single drop and drop swarm investigations. The dispersed phase is n-heptane and it is used pure and also coloured with a non-water soluble red dye.…”

Experiments on breakup of bubbles in a turbulent flow

“…Unfortunately, despite the large quantity of models for the breakup frequency, the number of daughters and the daughter size distribution, relatively little experimental data suitable for their testing exists. Previous experiments can be categorized as follows Drop breakup in a stirred vessel, Drop breakup in a channel flow, in which an obstacle creates turbulent flow behind it, for example, the flow behind an orifice or an obstacle in the form of a blade of a Ruston turbine, Bubble breakup in a turbulent pipe flow or in a turbulent flow through a narrow gap of a homogenizer, Bubble or drop breakup in a turbulent flow generated by a jet or by a zero flux coaxial jets, Bubble breakup in other arrangements, such as a pipe flow with an impeller to promote turbulence or in a static mixer …”

Three‐Dimensional Observation of Single Air Bubble Breakup in a Stirred Tank

“…. Previous experiments on single fluid particle breakup have been investigated in turbulent pipe flows , orifices , extraction columns , special breakup cells , , and stirred tanks , , .…”