Events

Speaker:  Dr. Davide Picchi, Postdoctoral Research Fellow of Geology at the Energy Resources Engineering Department at Stanford University

Title of Seminar: “Dynamics of multiphase flow and complex fluids in horizontal and vertical systems”

Abstract: Multiphase flow of complex fluids is frequently encountered in production wells and in pipelines. Even if dense emulsions and waxy oils behave as non-Newtonian fluids, the effects of complex rheology on two-phase flow characteristics are not yet completely understood. Firstly, I will focus on stratified flows of Newtonian/non-Newtonian shear-thinning fluids in horizontal systems, and I will discuss aspects relevant to practical applications, such as the hold-up and lubrication effects. Then, I will demonstrate how rigorous linear stability analysis can be employed (i) to gain a deep understanding of instability mechanisms and (ii) to provide guiding principles to control the transition to flow regimes unfavourable to operations (e.g. slug flow).  I apply these findings to develop a novel numerical tool, based on a slug-capturing approach, which is able to reproduce both transient flow features as well as the stratified-to-slug flow transition. Finally, I will mention how bistability may arise in vertical systems due to the effect of gravity.

Biography:  Davide Picchi is a Postdoctoral Research fellow in the Energy Resources Engineering Department at Stanford University. He is interested in investigating multiphase flow of complex fluids at different scales, spanning from flow in pipes to pore-scale dynamics in porous media, with a focus on petroleum and geophysical applications. Over the years, he has focused both on theory development and experiments. Specifically, he has worked on stability theory, upscaling techniques (e.g. volume-averaging and homogenization), and uncertainty quantification. Before joining Stanford, he was a Postdoctoral Research fellow in the group of Profs. N. Brauner and A. Ullman at Tel Aviv University, and he received his Ph.D. in Mechanical Engineering from the Università degli Studi di Brescia (Italy) under the supervision of Prof. Pietro Poesio.