Prof. Carlo Massimo Casciola
Title of the Lecture:
The nucleation process and its coupling to the macroscale
Short Bio:
Prof. Carlo Massimo Casciola is presently the Dean of the Faculty of Civil and Industrial Engineering at La Sapienza University of Rome where he leads a research group based at the Mechanical and Aerospace Department, working on the dynamics of complex flows and the coupling of macroscopic flows with a microstructure. He has given contributions to turbulence, particulate-, polymers-laden, and multiphase flows, micro/nanofluidics through molecular dynamics simulations and free-energy methods, and mesoscale methods (phase field methods and fluctuating hydrodynamics). He received the prestigious ERC Advanced Grant, BIC – Following Bubbles from Inception to Collapse, and recently developed a novel microfluidic chip to study cavitation-enhanced blood vessel permeability thanks to the ERC Proof of Concept grant INVICTUS, IN VItro Cavitation Through UltraSound.
Abstract of the Lecture:
Bubble nucleation is a ubiquitous phenomenon whose prediction proved a formidable task, particularly in the case of water. Here a self-contained model is discussed which is shown able to accurately reproduce data for bulk water over the most extended range of temperatures for which accurate experiments are available [1]. The computations are based on a Ginzburg-Landau model which, as only inputs, requires a reliable equation of state for the bulk free energy and the interfacial tension of the water-vapor system. Rare event techniques borrowed from statistical mechanics allow the determination of the free-energy barrier and the nucleation rate. By consistently including thermal fluctuations [2] in the spirit of Fluctuating Hydrodynamics, the approach is extended to dynamic conditions in presence of solid walls of different wettability [4] to allow coupling with fluid motion [4]. The talk will focus on the wall wettability in compliance with the fluctuation-dissipation balance, a crucial point in the context of the fluctuating hydrodynamics theory. Depending on time availability, new, still unpublished results concerning the coupling of nucleation and fluid flow, the effect of micro-confinement, and time-changing thermodynamic conditions will also be addressed.
References
[1] F. Magaletti, M. Gallo, C.M. Casciola, Water cavitation from ambient to high temperatures, Scientific Reports 2021, 11 1.
[2] M. Gallo, F. Magaletti, C.M. Casciola, Thermally activated vapor bubble nucleation: the Landau-Lifshitz/Van der Waals approach, Phys. Rev. Fluids. 2018, 3, 053604.
[3] M. Gallo, F. Magaletti, C.M. Casciola, Heterogeneous bubble nucleation dynamics, Journal of Fluid Mechanics 2021, 906 10.
[4] M. Gallo, F. Magaletti, D. Cocco, C.M. Casciola, Nucleation and growth dynamics of vapor bubbles, Journal of Fluid Mechanics 2020, 883.
