Micro & Nano Flows for Engineering
The micro & nano flows group is a research partnership between the Universities of Warwick and Edinburgh, and Daresbury Laboratory. We investigate gas and liquid flows at the micro and nano scale (where conventional analysis and classical fluid dynamics cannot be applied) using a range of simulation techniques: molecular dynamics, extended hydrodynamics, stochastic modelling, and hybrid multiscaling. Our aim is to predict and understand these flows by developing methods that combine modelling accuracy with computational efficiency.
Targeted applications all depend on the behaviour of interfaces that divide phases, and include: radical cancer treatments that exploit nano-bubble cavitation; the cooling of high-power electronics through evaporative nano-menisci; nanowire membranes for separating oil and water, e.g. for oil spills; and smart nano-structured surfaces for drag reduction and anti-fouling, with applications to low-emissions aerospace, automotive and marine transport.
EPSRC Programme Grant in Nano-Engineered Flow Technologies
Our work is supported by a number of funding sources (see below), including a 5-year EPSRC Programme Grant (2016-2020). This Programme aims to underpin future UK innovation in nano-structured and smart interfaces by delivering a simulation-for-design capability for nano-engineered flow technologies, as well as a better scientific understanding of the critical interfacial fluid dynamics.
We will produce software that a) resolves interfaces down to the molecular scale, and b) spans the scales relevant to the engineering application. As accurate molecular/particle methods are computationally unfeasible at engineering scales, and efficient but conventional fluids models do not capture the important molecular physics, this is a formidable multiscale problem in both time and space. The software we develop will have embedded intelligence that decides dynamically on the correct simulation tools needed at each interface location, for every phase combination, and matches these tools to appropriate computational platforms for maximum efficiency.
This work is strongly supported by nine external partners (see below).
- “Nano-Engineered Flow Technologies: Simulation for Design across Scale and Phase” EPSRC Programme Grant EP/N016602/1 01/16-12/20 (£3.4M)
- “The First Open-Source Software for Non-Continuum Flows in Engineering” EPSRC grants: EP/K038427/1 K038621/1 K038664/1 07/13-06/17 (£0.9M)
- “Multiscale Simulation of Interfacial Dynamics for Breakthrough Nano/Micro-Flow Engineering Applications” ARCHER Leadership Project 11/15-10/17 (£60k in supercomputer computational resource)
- “Skating on Thin Nanofilms: How Liquid Drops Impact Solids” Leverhulme Research Project Grant 08/16-08/19 (£146k funding a 3-year PDRA)
- Airbus Group Ltd
- Bell Labs
- European Space Agency
- Jaguar Land Rover
- Oxford Biomedical Engineering (BUBBL)
- TotalSim Ltd
- Waters Corporation
Latest news and blogs
Prof. Duncan Lockerby, University of Warwick
It's a pleasure to welcome three new starters to Warwick and the Micro Nano Flows team. Laura Cooper joins us as a post-doctoral researcher, and will be working on multi-phase flow in porous media with James Sprittles. Yixin Zhang and Jacqueline Misfud are in the first weeks of their PhDs. Yixin will be investigating nano film stability (with molecular dynamics) and Jacqui will be researching micro-bubble cavitation (with CFD) in partnership with Waters Limited. We wish all three the best of luck in their research!
Dr James Sprittles, University of Warwick
Dr Shiwani Singh has joined the Micro and Nano Flows team at Warwick, where she will be based in the Maths Institute. She will be looking into multiscale modelling of viscoelastic flows over the next couple of years.
Prof. David R Emerson, Daresbury Laboratory
Arnau Miro from the Universitat Politècnica de Catalunya won a HPC Europa-2 grant for a 13-week visit to the Daresbury group. Arnau will be working on advanced meshing and code coupling strategies and starts his visit mid-January.
Dr Jianfei Xie, Research Associate, University of Edinburgh
The 5th European Conference on Microfluidcs and the 3rd European Confenrencen on Non-Equilibrium Gas Flows (NEGF) had been held on 28th of Febraury - 2nd March at the University of Strasboug, France. Two members from our MNF Group, Prof. David Emerson and I, and one of Prof. Yonghao Zhang's Postdocs, Dr. Minh-Tuan Ho attended this joint conference, and we all gave 15 minutes long presentations. David also chaired my session on the second day afternoon of the conference. Lots of simulations and modelling had been presented in the conferene on NEGF, including the conventional direct simulation Monte Carlo (DSMC) solver for rarefied gases and molecular dyanmics (MD) simulations such as CH4/CO2 molecules hitting graphitic walls. There were plenty of experiments of microfluidics, including the vapour adsorption phenomena onto liquid desiccant droplets (the presnter who is a first-yesr PhD student in Japan was awarded the first prize for the best presentiaons) and microchannel flows such as formation dynamics of ferrofluid droplets in a T-junction. The psoters were also very exciting and many beatiful works had been displayed during the coffee break. The local French committee did a really good job and were very helpful. The next conference will be held in Germany in 2020 and all are welcome to present and share their interesting research. (I got the soft copies of abstracts of this conference and I am happy to send them to you if you are interested)
Martin Nikiforidis, PhD Student, University of Edinburgh
One of the interested facts about water is that it does not always freeze and 273.15 K, as it normally does. Actually pure water, water that has no impurities and free of nucleation sites, can stay in liquid form up to 224.8 K.
When the purer water is supercooled it is very easy to freeze it, because any iteraction with the water molecules in that state can result in the fomration of nuclation sites, that will instantly result in the freezing of the water.
This video is a simple and nice representation on how to supercool water and then freeze it instantly!
Yixin Zhang, PhD Student, University of Warwick
Helium, which turns into liquid at about 4.2 Kelvin, can be held in a container like a beaker due to gravity. But when it is cooled further to below approximately 2 Kelvin, it creeps up the surface of the beaker and leak. At this temperature, liquid helium is called as superfluid due to its odd properties. For example, the liquid's viscosity becomes nearly zero. Because of that, the fluid can flow very easily even as a result of the smallest pressure. On one hand, a thin liquid helium film will appear as the liquid wet the surface of the beaker. On the other hand, liquid helium has smaller dielectric permittivity than any other medium (except vapour), which results in a negative Hamaker constant and a repulsive van der Waals force across the film. This will act to thicken the film and make the liquid helium flow from the bottom of the beaker to its surface and thus leak.