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 (£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 (£146k funding a 3-year PDRA)
- Airbus Group Ltd
- Bell Labs
- European Space Agency
- Jaguar Land Rover
- National Physical Laboratory
- Oxford Biomedical Engineering (BUBBL)
- TotalSim Ltd
- Waters Corporation
Latest news and blogs
This week Dr Matthew Borg attended the 2016 SIAM Conference on Mathematical Aspects of Materials Science in Philadelphia and gave an invited talk on his recent multiscale methods at the mini symposium: "Multiscale Modelling Methods for Complex Fluids and Soft Matter".
Dr Jun Zhang, Research Associate, University of Edinburgh
Dr Jun Zhang attended the EMN meeting on droplets in San Sebastian, Spain on May 9-14. He gave an invited talk on the evaporation of salt water droplets and electrowetting: "Controlling the Deposit Patterns of Evaporated Salt Water Nano Droplets Using Electric Fields". In addition, he was one of the session chairs for droplet dynamics.
Dr Stephen M. Longshaw, Research Fellow, Daresbury Laboratory
The fourth OpenFOAM UK&I user meeting was held at Exeter university last week on the 18th and 19th of April. The next event is expected to be held at Warwick university but details are still being confirmed.
I have reported these events on this blog before but for anybody either using, or interested in using OpenFOAM for their research they are a valuable (and yet free) event well worth making the effort to go to. The intention is that this event travels all over the UK & Ireland (as the name suggests!), it has now been as far south as Exeter and as far north as Warrington within England, but now needs to spread its wings further and make it to Scotland, Wales or Ireland. To get involved in organising one of these events please contact either the last organising committee (http://ukri-openfoam.ex.ac.uk/) or the authors of the foam-extend project (http://www.extend-project.de/), or come along to the next one and volunteer!
The first day saw a number of training events around OpenFOAM using the computing facilities at Exeter university while the second day saw a number of invited talks from the OpenFOAM community, showing a diverse set of works ranging from FSI with OpenFOAM through to the use of OpenFOAM to design 3D printed heat exchanges and its use in refining the design of ovens used to cook pastry based products!
There was lively discussion throughout the day, culminating in a discussion about the current HPC performance of OpenFOAM and whether a) it needs to be improved, b) what needs to be improved and c) how do we do it as a community? The general concencus was that performance was below par and many reduce the scope of their problems to fit OpenFOAM rather than the other way around, this can't be the right way! Performance is clearly something that the community needs to tackle and so a number from the meeting went away with making this a priority within their organisations... so watch this space!
Dr David Stephenson , Research Fellow, University of Warwick
On Thursday 6th May, researchers from the Universities of Warwick and Edinburgh were joined by Prof. Terry Blake (Emeritus Professor at the University of Mons) for a workshop on the "Molecular Modelling of Interfacial Dynamics". The workshop, hosted by Dr James Sprittles at the University of Warwick, provided a platform for discussing the prominent challenges involved in the simulation of micro-droplets and surrounding small-scale phenomena. Understanding the governing physics at fluid interfaces on the molecular level underpins a number of emerging technologies. For example, controlling the break-up and coalescence of droplets is crucial to the operation of 3D printers; understanding the wetting characteristics of droplets is important for producing uniform coating films which prohibit air entrainment; regulating the evaporation of solute-containing liquid droplets can reduce the damage to surfaces due to weathering; and understanding the fluid-gas interface near micro-structures such as carbon nanotubes is key for developing drag-reducing surfaces.
There were seven presentations in total, covering a range of topics from the fundamental physics of droplet break-up, impact, and wetting, to the use of multiscale methods and machine learning techniques to enhance molecular modelling capabilities. See below for the complete list of presentations, some of which were exquisitely captured by our official photographer (also James).
- A multiscale method for non-equilibrium gas flow simulation in high-aspect-ratio geometries (Duncan Lockerby)
- Accelerating a multiscale continuum-particle fluid dynamics model with on-the-fly machine learning (Dave Stephenson)
- Water flow through and over carbon nanotubes: applications to drag-reducing surfaces and water filtration membranes (Matthew Borg)
- Droplets evaporation and spreading: Molecular dynamics and sequential hybrid simulation (Jun Zhang)
- Dynamic wetting, forced wetting and hydrodynamic assist (Terry Blake)
- The dynamics of rarefied gases between colliding bodies (Alex Patronis)
- How liquid drops form (James Sprittles)
Also, there were biscuits. This is important.
Dr Srinivasa B Ramisetti, Research Fellow, University of Edinburgh
Recenlty I was reading a lot of research articles looking for information on slip lengths, for flow over hydrophobic/hydrophilic surfaces, reported from various experiments and numerical simulations in order to compare our slip length calculations extracted from simulations. There is a huge number of journal articles and reviews on slip length measurements from experiments and simulations. Below is a list of links to articles wherein slip lengths reported in different papers are collected and presented in a nice tabular fashion that is easy for one to refer.