## Interview: Women in STEM Wednesday

by GirlsWhoStem

by GirlsWhoStem

That time that people got mad about turbulence

by Katie Steckles

by Bethany Clarke and Ellen Jolley

Come and meet the real people *Behind the research*

A fluid dynamicist and an astrophysicist walk into a bar…

Revolutionising PhD the Application Process

Phillips, Katie A., and Paul A. Milewski. "Lubrication-mediated rebounds off fluid baths."* arXiv preprint arXiv:2406.17138 (2024).*

We present herein the derivation of a lubrication-mediated (LM) quasi-potential model for droplet rebounds off deep liquid baths, assuming the presence of a persistent dynamic air layer which acts as a lubricating pressure transfer.

Phillips, K. A., Cimpeanu, R., & Milewski, P. A. (2024). Modelling droplet rebounds off fluid baths. *arXiv preprint arXiv:2406.16750.*

Through considering separately the bath, air, and drop regions of fluid, we introduce a fully coupled reduced dynamic model of two-dimensional droplets rebounding off liquid baths, which incorporates an evolving lubricating air layer

A droplet falling towards a free surface must first make its way through a layer of air acting as a barrier between the two liquids, preventing coalescence. In a millimetric regime, the capillary action of the free surface may dominate the dynamics of the interaction and is able to provide an upward kick to rebound the droplet prior the full evacuation of the air layer, which would have allowed coalescence. In such a regime, the trapped air acts as a lubrication layer between the impactor and the free surface. To leading order, such a millimetric droplet acts as a rigid sphere, allowing developments of numerical models for solid-liquid impacts to be a reasonable approximation of droplet dynamics. In this talk, we present the development of a 2D model of a millimetric solid sphere impacting on a free surface. By taking a multi-scale approach, we include the air layer as a dynamical component in the system through coupling an asymptotic derivation of the leading order problem, with psuedo-spectral methods to model the behaviour of the free surface, and smaller scale lubrication regime for the dynamics of the cushioning layer.

A droplet about to impact a free surface must first make its way through a layer of air acting as a barrier preventing coalescence. In a millimetric regime, the capillary action of the free surface may dominate the dynamics of the interaction and is able to provide an upward kick to rebound the droplet prior the full evacuation of the air layer, which would have allowed coalescence. In such a regime, the trapped air acts as a lubrication layer between the impactor and the free surface. To leading order, such a millimetric droplet acts as a rigid sphere, allowing developments of numerical models for solid-liquid impacts to be a reasonable approximation of droplet dynamics. In this talk, we present the development of a 2D model of a millimetric solid sphere impacting on a free surface. We take a multi-scale approach to include the air layer as a dynamical component in the system by coupling an asymptotic derivation of the leading order problem, with psuedo-spectral methods to model the behaviour of the free surface, and smaller scale lubrication regime for the dynamics of the cushioning layer.

A droplet falling towards a free surface must first make its way through a layer of air acting as a barrier between the two liquids, preventing coalescence. In a millimetric regime, the capillary action of the free surface may dominate the dynamics of the interaction and is able to provide an upward kick to rebound the droplet prior the full evacuation of the air layer, which would have allowed coalescence. In such a regime, the trapped air acts as a lubrication layer between the impactor and the free surface. To leading order, such a millimetric droplet acts as a rigid sphere, allowing developments of numerical models for solid-liquid impacts to be a reasonable approximation of droplet dynamics. In this talk, we present the development of a 2D model of a millimetric solid sphere impacting on a free surface. By taking a multi-scale approach, we include the air layer as a dynamical component in the system through coupling an asymptotic derivation of the leading order problem, with psuedo-spectral methods to model the behaviour of the free surface, and smaller scale lubrication regime for the dynamics of the cushioning layer.

The phenomena of a small sphere or liquid droplet rebounding from the free surface of a deep bath has been studied experimentally and with a variety of models. It is established that an important part of the physics is a thin layer of air separating the droplet and the free surface, though current reduced models fail to fully capture the dynamics of this air layer. Assuming quasi-potential flow in the deep liquid bath regime, we are able to develop a fully coupled dynamic model for the drop-air-bath interaction, using lubrication theory to deduce the pressure transfer between the drop and free surface. In this talk, we present the development of this model in two-dimensions for both rigid and deformable impact, as well as highlight some key results from numerical simulations of the system.

The phenomena of a small sphere or liquid droplet rebounding from the free surface of a deep bath has been studied experimentally and with a variety of models. It is established that an important part of the physics is a thin layer of air separating the droplet and the free surface, though current reduced models fail to fully capture the dynamics of this air layer. Assuming quasi-potential flow in the deep liquid bath regime, we are able to develop a fully coupled dynamic model for the drop-air-bath interaction, using lubrication theory to deduce the pressure transfer between the drop and free surface. In this talk, we present the development of this model in two-dimensions for both rigid and deformable impact, as well as highlight some key results from numerical simulations of the system.

3 minute lightnight talk to introduce ‘KatDoesMaths’ to the world of Maths communication in the UK.

3 minute lightnight talk to introduce ‘KatDoesMaths’ to the world of Maths communication in the UK.

Outside of my PhD research I spend my time doing maths communication under the name “KatDoesMaths”, and what better way to describe this talk. It’ll be broken down into three sections: The first “Kat”, I’ll talk you through my journey to get to where I am. “Does” is where I want to share with you all the tips and tricks of the Maths Communication trade that I’ve picked up over the years, and how to get started if you’re thinking about getting into outreach. And then finally I’m going to actually communicate some “Maths” with you. It’s a bold statement to talk about my ability to communicate maths and then follow it up with a research talk, but I’m excited to share with you my work (and there are some pretty pictures at the end!). Away from the glitz and glam of Maths Communication, I study fluid dynamics. In order for a droplet to rebound from a liquid surface there needs to be an air layer keeping the two liquids separate, else the droplet will coalesce. My research is investigating the dynamics of this air layer, and I will introduce my numerical model which is able to recreate this system.

Welcome to the wonderfully wacky world of fluid dynamics. Using everyday examples, Kat will introduce the equations that govern all fluid motion and show how a small change in a mathematical equation can describe a huge range of different fluid phenomena.

Welcome to the wonderfully wacky world of fluid dynamics. Using everyday examples, Kat will introduce the equations that govern all fluid motion and show how a small change in a mathematical equation can describe a huge range of different fluid phenomena.

Welcome to the wonderfully wacky world of fluid dynamics. Using everyday examples, Kat will introduce the equations that govern all fluid motion and show how a small change in a mathematical equation can describe a huge range of different fluid phenomena.

This minisymposia was organised by myself and Fraser Waters, as we wanted to increase discussions about communication styles in mathematics. AS such we invited a range of speakers each with their own unique format for communicating mathematics.

One of the most integral parts of research is the dissemination of knowledge, and being able to do this effectively can drastically improve the impact of your work. There are so many more routes of comunication that we as academics are able to utilise beyond the standard routes of writing papers and presentinc at conferences with talks and posters.This talk is an introduction to the breath of communication styles we will welcome in the rest of the minisymposia, as well as an exploration of the key concepts that are widely used by effective communicators.

In this talk we will develop a keen understanding of all the physical aspencts that make up the equations that govern nearly everything in the world around us. The Navier-Stokes equations describe how a fluid moves and interacts with its environment, and by the end of this talk we will se ehow they can be applied to the smallest rain buddle, all the way up to understanding the cosmos.

This workshop was a full day 10-5 session where I led the room of 30 PhD students through their first steps towards maths communication. The day consisted of an introductory lecture, three guided activities which built off eachother in an easy to follow modular manner, and then a reflection and discussion period.

A brief explanation of the origin of PhD Your Way, and advertising the event to the PiForum 2024 attendees.

A droplet falling towards a liquid bath will only rebound in the presence of a persisting thin layer of air, which separates the two liquids from coalescing. Within this talk we will introduce a fully coupled dynamic model for the drop-air-bath system, through assuming quasi-potential flow int he deep liquid bath, and a lubrication approximation in the air layer. Trhough obtaining a thin film equation in the air layer, we deduce the pressure transfer between the drop and the free surface, and the bounds of the lubrication region where this pressure is felt. We demonstrate the axisymmetric impacts of solid and liquid spheres on deep liquid baths in both two and three dimensions, and demonstrate the potential for this lubrication-model to capture complex repeated bouncing behaviours through simulating Faraday pilot-wave dynamics, where drop-bath pairings are able to eneter stable periodic behaviour.

Undergraduate course, *University 1, Department*, 2014

This is a description of a teaching experience. You can use markdown like any other post.

Workshop, *University 1, Department*, 2015

This is a description of a teaching experience. You can use markdown like any other post.