Non-Equilibrium Fluid Dynamics for Micro/Nano Engineering Systems

Lead Research Organisation: University of Strathclyde
Department Name: Mechanical and Aerospace Engineering

Abstract

This research is about simulating and designing the engineering flow systems that will form a major part of the responses to health, transportation, energy and climate challenges that the world faces over the next 40 years.The United Nations estimates that by 2050 four billion people in 48 countries will lack sufficient water. But 97 percent of the water on the planet is saltwater, and much of the remaining freshwater is frozen in glaciers or the polar ice caps. If the glaciers in the polar regions continue to melt, as expected, the supply of freshwater may actually decrease: freshwater from the melting glaciers will mingle with saltwater in the oceans and become too salty to drink, and rising sea levels will contaminate freshwater sources along coastal regions. Technologies for large-scale purification of seawater or other contaminated water to make it drinkable are therefore urgently needed.At the same time, figures from the US Energy Information Administration project an average growth rate of 2.7 percent per year for transportation energy use in non-OECD countries to 2030 - this is 8 times higher than the projected rate for OECD countries. China's passenger transportation energy use per capita alone is projected to triple over this period, and India's to double. Improving the fuel efficiency of air and marine transport is a strategic priority for governments and companies around the world, and will have the added benefit of reducing emissions and helping address climate change. Micro and nano scale engineering presents an important opportunity to help meet these pressing challenges. For example, early indications are that membranes of carbon nanotubes have remarkable properties in filtering salt ions and other contaminants from water. Also, controlling the turbulent drag on aircraft and ship hulls, which is a major inefficiency in modern transportation, may be achievable by embedding micro systems and/or nano structures over the vehicle's surface.This cross-disciplinary research programme targets the unconventional fluid dynamics that is key to innovating in these visionary applications. The work is strongly supported by 9 external partners, ranging from large multinational companies to SMEs and public advisory bodies, and brings together established research groups from two major UK universities and a national research institute. We will deliver a comprehensive new technique for simulating mixed equilibrium/non-equilibrium fluid dynamics at the nano and micro scale, and deploy it on three important technical challenges that span the range of economic and societal impact, from energy to healthcare. These are drag reduction in aerospace, applications of super-hydrophobic surfaces to marine transport, and water desalination / purification. In this research we aim to:- accurately predict the performance of the proposed technologies;- optimise their design within realistic engineering parameters;- propose new designs which exploit flow behaviour at this scale for technological impact.The research partnership leading this Programme has flourished over 10 years into an international driver for understanding these kinds of thermodynamically non-equilibrium flows, attracting substantial joint funding and producing co-authored research publications. The partnership is poised to effect the step-change in non-equilibrium flow simulation capabilities that is needed to make new technologies at the micro and nano scale practicable, beyond any currently conceived.

Planned Impact

Impact from this Programme will be academic, industrial, environmental and societal. Encapsulating non-equilibrium fluid dynamics within a tractable design methodology presents an important direct benefit to the UK economy: by enabling flow design at the micro and nano scale, technologies with completely new capabilities can be devised, with clear long-term industrial and societal potential, including emissions reduction, clean water provision, and other applications of critical importance to the sustainability of our environment and global standard of living. This Programme will also shed new light on the physics of micro and nano flows that will benefit industrial and other researchers in fluid dynamics directly, as well as many cognate areas indirectly, such as micro-processor cooling, hypersonic aerodynamics, single DNA analysis, clinical pathology, and nano fuel-cell technology. Our nine industrial SME and multinational partners, and non-departmental public bodies, will be the primary routes for delivering non-academic medium- to long-term impact over the Programme period and the following 5 years, including: - EADS, on simulating new technologies for active drag control for aircraft; - EDF, on multiscale fluid/surface interactions in pump seals and nuclear fuel shipping casks; - Weir Oil & Gas, on micro and nanoscale lubrication and hydraulic component design; - the Health Protection Agency (advisory body to the UK Department of Health), on nano scale transport within the human respiratory tract; - Jaguar Land Rover, on aerodynamic drag reduction and surface treatments for water repellency; - Exa Corporation, on developing non-equilibrium flow techniques to complement their lattice Boltzmann code; - OpenCFD Ltd, an SME that is the OpenFOAM project architect, and who now employ two of our trained researchers; - UK Sport (executive body for the UK Department for Culture, Media and Sport), on performance improvements for British athletes; - Reaction Engines Ltd, an SME requiring a new generation of high-performance microchannel heat exchangers. New external beneficiaries will be actively sought as the Programme progresses, and invited to participate on the same basis as the initial partners above. Programme activities to engage with these and other external non-academic beneficiaries to maximise impact are: 1) two-way secondments of key personnel from external partners and the Programme to gain first-hand experience of industrial priorities and research challenges, to identify mutual research opportunities, and to upskill in non-equilibrium fluid dynamics and the software tools developed in the Programme. 2) participation of the external partners in the Programme's Steering & Impact Committee, providing advice and support to the Programme projects. 3) the development of trained Programme personnel who will be able to work to sustain future UK efforts in this field long-term in government laboratories, industry (including our external partners) or in academia. 4) using Knowledge Transfer Networks and our EU FP7 GASMEMS network (17 pan-Europe academic and industrial partners) as platforms to share knowledge on technological opportunities arising from the research. 5) one-day workshops every 6 months, for Programme personel and all external partners to discuss work-in-progress, and new technical and impact opportunities. 6) in years 3 and 5, we will organise 3-day open symposia, advertised internationally, to present results within their specific international research context, across the academic and industrial sectors. 7) any developed simulation tools that are not commercially sensitive will be distributed open-source. 8) a professional website will report our latest results, including research paper preprints and codes (downloadable freely). This will also serve as an additional point of contact for potential new industrial and academic partners, as well as the general public.

Publications

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Agius Anastasi A (2016) Mechanical properties of pristine and nanoporous graphene in Molecular Simulation

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Alexiadis A (2013) A Laplacian-based algorithm for non-isothermal atomistic-continuum hybrid simulation of micro and nano-flows in Computer Methods in Applied Mechanics and Engineering

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Alexiadis A (2014) The atomistic-continuum hybrid taxonomy and the hybrid-hybrid approach THE HYBRID-HYBRID APPROACH in International Journal for Numerical Methods in Engineering

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Babac G (2014) Knudsen heat capacity in Physics of Fluids

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Babac G (2014) Molecular Dynamics Simulation of Classical Thermosize Effects in Nanoscale and Microscale Thermophysical Engineering

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Babac G (2014) Thermal Creep Flow of Helium Gas at Cryogenic Temperatures in Journal of Physics: Conference Series

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Borg M (2013) A multiscale method for micro/nano flows of high aspect ratio in Journal of Computational Physics

 
Description This Programme Grant laid the foundation for a raft of multi-scale models and simulation tools for micro and nano-scale fluid dynamics. These tools allow scientists and engineers to better understand and design micro and nano-scale fluid dynamics and its applications.
Exploitation Route Exemplars of future research that this project now facilitates include:

1. Airborne pathogens and particulate matter: advancing modelling & simulation
Airborne particulate matter with a diameter of 2.5┬Ám or less (known as PM2.5) contributes to a wide range of adverse health effects - an estimated 4.2 million premature deaths were caused by particulate matter in 2016 alone (Source: WHO). Viral infections are transported in water drops of a similarly small size, which become airborne when we cough and sneeze, and that can survive (before being evaporated) for very long periods of time. Understanding the flow characteristics of such pathogens and particulate, through modelling and simulation, is critical to designing future measures to contain and control them, including designing effective filtration systems and cheap, reliable sensors. The size of these objects, be they rigid particles or evaporating drops, can be comparable to the molecular `mean free path', and demand modelling and computational methods beyond the state of the art. In the UK we are in a position to pioneer and exploit this emerging opportunity - namely, in flexible tools for the aerodynamic prediction of very slow, very small objects.

2. Computational Modelling for a Revolution in the Manufacture of Nano-Technologies
Technologies of the future are demanding computational modelling tools that enable us to understand the fluid dynamics of the nanoscale, where molecular Brownian motions drive remarkably counter-intuitive flow patterns. Within this nano-world, the traditional design tool of computational fluid dynamics (cfd) software is impotent and molecular simulations are prohibitively expensive. However, the UK is at the forefront of attempts to develop 'nano-hydrodynamic' mathematical models; inspired by molecular simulations yet operating within computationally-tractable environments. Therefore, a unique opportunity exists to exploit this expertise and develop disruptive design-for-simulation capabilities that can put the UK at the forefront of the manufacture of fluid-based nano-technologies.
Sectors Electronics,Energy,Environment,Healthcare

URL http://www.micronanoflows.ac.uk
 
Description Joint research with Science & Technology Facilities Council (STFC) 
Organisation Science and Technologies Facilities Council (STFC)
Country United Kingdom 
Sector Public 
PI Contribution University of Strathclyde researchers worked on this project with researchers from Science & Technology Facilities Council (STFC)
Start Year 2011
 
Description Joint research with University of Warwick 
Organisation University of Warwick
Country United Kingdom 
Sector Academic/University 
PI Contribution University of Strathclyde researchers worked on this project with researchers from University of Warwick
Start Year 2011
 
Title OpenFOAM 2.4.0 plus the MicroNanoFlow Group Codes 
Description OpenFOAM is a free, open source computational fluid dynamics (CFD) software package released by the OpenFOAM Foundation. It has a large user base across most areas of engineering and science, from both commercial and academic organisations. In this GitHub repository we include codes developed (as an extension to OpenFOAM) for simulating non-continuum fluid dynamics (e.g. mdFoam and dsmcFoam). The Micro & Nano Flows (MNF) Group are the original authors of the mdFoam and dsmcFoam applications. This repository provides up to date versions of these applications (name mdFOAM and dsmcFOAM), with the groups most recent developments included along with documentation and new tutorial cases. 
Type Of Technology Software 
Year Produced 2016 
Open Source License? Yes  
Impact Impact is difficult to ascertain at this stage, as it is in early release. 
URL https://github.com/MicroNanoFlows