Welcome to the homepage of Lennon O'Naraigh

I am an applied mathematician by training, interested in the application of any mathematical tool to any problem of practical interest, especially the difficult ones. More specifically, I am interested in reduced-order models of fluid flow, ones that can be analyzed (if not solved) via good old-fashioned pen-and-paper techniques. This mostly involves problems in droplets and films, as well as hydrodynamic stability. I have worked on other things in the past, such as two-dimensional turbulence (pictured in the background), high-end simulations, and liquid crystals.

I was an undergraduate at Trinity College Dublin, and I later obtained my Ph.D. at Imperial College London, under the supervision of Jean-Luc Thiffeault. I started a lectureship at University College Dublin in January 2010. Before joining UCD, I spent two very stimulating years as a postdoc in the Department of Chemical Engineering, Imperial College London.

My main current work is on the modelling flows in droplets along with collaborators Prashant Valluri (Edinburgh), and Alidad Amirfazli (York University, Toronto). Along with Richard Smith (UCD), I am also working on novel methods to model contact-line motion, inspired by something called the Geometric Thin-Film Equation, which I stumbled upon when dilly-dallying on a blackboard in 2019 with my friends Darryl Holm (Imperial), and Cesare Tronci (Surrey). Such flows have important applications in industry but provide good grounding for a theoretician, as they can be experimented on and visualized using modern high-speed cameras. Having a connection between the equations and the real physical world is an essential epistemiological and even moral part of theoretical modelling.

In the past I have also collaborated with many distinguished scientists working on high-end simulation of multiphase flows. This has led to the development of a highly-parallelized two-phase Navier-Stokes solver called TPLS, which is in active use by a number of European research groups. The developmenmt of TPLS was a labour of love accomplished by myself, Prashant Valluri (Chemical Engineering, Edinburgh), and the Edinburgh Parallel Computing Centre (Iain Bethune, David Scott, Mike Jackson, and Toni Collis). I have also done a similar piece of code development which solves the Cahn-Hilliard equation in three dimensions with Aurore Naso (LMFA, CNRS Lyon). All of this work is based on the hard work and the visionary ideas of Professor Peter Spelt, formerly of LMFA in Ecole Centrale de Lyon, who sadly passed away in 2020.

Please click on the headings above for more information. Since a little bit of repetition is good, information for prospective Ph.D. students can also be found by clicking directly through here, while information for current and past undergraduate students can be found here. Finally, my CV can be download here.

Office hours, Office location

My office is not the one in the picture. That's the Principal's Office in St. Enda's School, Rathfarnam, once occupied by the visionary educator, soldier, and poet, Patrick Pearse. Instead, my office is E4.10, located in the UCD Earth Institute. This is on the fourth floor of Science East, at the very top of the spiral staircase. Unfortunately, access to this area is by swipe card only, so students will have to make an appointment to see me.