ME Faculty Candidate Nathanael Machicoane Research Seminar
- Thursday, February 14, 2019 at 2:10pm
- Roberts Hall, 321 - view map
From Climate Modeling to Jet Engines: Understanding Turbulent Multiphase Flows
Postdoctoral Researcher at the University of Washington -
Multiphase & Cardiovascular Flow Lab
Abstract: Multiphase flows are composed of a fluid, called the continuous phase, carrying one or several other phases – such as solid ash particles in air – or different immiscible fluids in the same phase – such as oil droplets in water. In this talk, I will describe a series of problems that are important to societal challenges and that include complex physics that are still poorly understood: those in which the continuous phase is a turbulent flow and the dispersed phase is dilute and formed by individual inclusions. This talk will present two aspects of such flows and their experimental investigations: 1) turbulent heat transfer on large spheres and 2) the control of liquid break-up and spray formation. In the first half of the talk, I will present how to measure the turbulent heat transfer on large ice spheres convected in a turbulent liquid flow, using a Lagrangian point of view, demonstrating the validation of a theoretical model for heat transfer in the ultimate regime of forced convection. This has environmental and industrial applications, such as hail formation in clouds, where heat transfer is an important mechanism for climate modeling. In the second half of the talk, I will focus on the dense two-phase flow at the exit of a two-fluid atomizer, investigated with high-speed synchrotron X-ray radiography. I will show how introducing angular momentum in the gas co-flow dramatically changes the topology of the atomized liquid jet. This is important for atomization control applications, such as ensuring engine restart at high altitude in the context of aircraft propulsion. Finally, I will discuss future plans for the study of turbulent multiphase flows with diverse applications.
Bio: Originally from France, Nathanaël Machicoane earned a B.S./M.S. in Physics from École Normale Supérieure de Lyon in 2011, with a focus on out-of-equilibrium systems. In 2014, he obtained his PhD for the study of the dynamics of large particles in turbulence with heat transfer, at the Physics Laboratory of École Normale Supérieure de Lyon. After his PhD, he studied inertial waves and turbulence in rotating fluids thanks to a post-doctoral fellowship at the FAST laboratory of Paris-Sud University. Dr. Machicoane is currently a post-doctoral researcher at the University of Washington, where he helps with the coordination of experimental research to establish Multiphysics controls of gas-assisted atomization through a Multi-University Research Initiative funded by the Office of Naval Research.
- Department of Mechanical & Industrial Engineering