Dr Yeaw Chu Lee

Proactive researcher and lecturer in mechanical engineering with over 15 years experience in research and teaching at under-graduate and post-graduate levels. Research interest in thermo-fluids and computational engineering of multi-scale and multi-phase soft matter and interfacial flows. Published over 56 scientific articles in international peer-reviewed journals and refereed conference proceedings. Successfully won 34 research grants, awards and studentships. Led course innovation and development underpinned by research and scholarly activities. Supervised over 59 B.Eng. and M.Eng. dissertations, 22 M.Sc. dissertations and 16 Ph.D. theses.

Qualifications

• Postgraduate Certificate in Academic Practice, Heriot-Watt University (2011-2012)
  
• Ph.D. in Mechanical Engineering, University of Leeds (2000-2004)
  
• M.Eng. (Hons.) in Mechanical Engineering, University of Leeds (1996-1999)

Professional membership

• Fellow of Higher Education Academy (FHEA)

Teaching interests

• Engineering Mechanics
• Engineering Mathematics
• Software Engineering and Computing
• Fluid Mechanics
• Heat Transfer
• Aerodynamics
• Computational Fluid Dynamics

Research interests

Research activities

Principal research expertise in the area of thermo-fluids of multi-scale and multi-phase soft matter, liquids and interfacial flows; in particular, computational fluid dynamics and software development of highly efficient and scalable bespoke mesh and mesh-less numerical solutions.

Ph.D. Research

My Ph.D. in mechanical engineering was focused on the development of be-spoked numerical solvers to explore tribological problems in porous media flows. I developed and utilised advanced numerical approaches for solving non-linear PDEs via multigrid methods to accelerate solution convergence and is further enhanced using automatic adaptive local mesh refinement and time integration methods. My research work on efficient numerical methods has placed me at the forefront of fluids research and it was applied to investigate elasto-hydrodynamics lubrication of continuous velocity joint and transmissions for Toyota & Torotrak, and later in homogenisation of anisotropic flows in porous media. The developed automatic spatially adaptive and multigrid method was not only employed to provide fast and accurate solutions to model fluid flows in reservoirs, but also used to upscale heterogeneous material properties and with potential applications in biomedical, geothermal, and applied sciences in environmental engineering.

Post-doctoral research

The success of my Ph.D. research and expertise in CFD has presented me a research fellow opportunity to advance fundamental science in fluid mechanics to better understanding and predict complex and dynamic fluid/solid interactions of coating flows and formations of thin liquid films, rivulets and droplets. This involved advancing research (and extending those from earlier work with Kodak) in mathematical formulation and computational predictive capabilities of macro- and micro-scale fluid flow phenomena; these are often observed in processes such as spin and gravure coating, photo-lithography, micro-fluidics, food processes, wetting, drying and evaporations of paints, pesticides and inks. The dynamic interactions between the fluid and its environment required solutions from multiple phases that necessitate multi-coupled non-linear PDEs viz. lubrication and depth-averaged shallow water approximations and their relevant physics; the need for accurate and efficient solutions further widened my repertoire of skills in parallel computing, finite-elements methods, numerical treatment for minimisation and optimisation of processes using evolutionary algorithms. My research has propelled my work internationally, working with experts from around the world and those at scientific technology research facilities. Applications of my research were implemented and extended in collaborative projects with Cytec Industries in novel thin film gravure coating blade designs, the Food and Environment Research Agency (FERA) in minimising pesticide spray deposition, and Expro & BP in exploring scale deposition kinetics and fouling of oil production pipelines.

Innovation, Impact & Industrial Engagement

My research to date, as a researcher and lecturer is organised around broad themes in mathematical and numerical modelling of multi-scale and multi-phase thermo-fluids involving complex gas/fluid/solid interactions in soft matter, liquid and interfacial flows. The motivation of my research agenda sprung from my continued interest in the dynamic interaction and interplay between multiple phases and scales of physical, biological and natural occurring fluid flow systems. Here, I led fundamental fluid research in surface-tension dominated flows, in particular, using smoothed particle hydrodynamics (SPH), a mesh-less approach to supersede traditional mesh-based approaches, therefore, overcoming the latter’s inherent limitations at resolving physically realistic moving interfaces of complex flow phenomena. This is particularly important in multi-phase flows which frequently extends over large disparate scales in both space and time.

Inter-discipline research

My research spans across inter-disciplinary fields, working together with industrial partners, such as with Atomics Weapons Establishment and later STFC Daresbury Laboratories, in dynamically modelling large fluid and material deformations. In particular, to predict successful bonding or failure of thermal barrier coatings that result from high velocity impacts between feedstock and substrate of thermal and cold spray processes. In addition, optimisation of computational performance was explored using state-of-the-art computer architectures for scalable parallelisation implementation. The research in this area remained active with potential applications and interest from the defence and security industries.

In an initiated collaborative research with NiTech Solutions, my expertise in CFD helped advanced prediction of mixing performance of continuous oscillatory baffled reactors (COBR). The research through EPSRC Centre for Innovative Manufacturing in Continuous Manufacturing and Crystallisation (CMAC) supported a PhD studentship to explore optimised mixing conditions for pharmaceutical crystallisation processes. The work investigated residence time distribution and settling dynamics of crystal formations in COBRs using traditional CFD techniques while developing a novel approach using SPH to accurately predict and historically track and trace mixing of multiple flow species.

An inter-discipline research project with collaborators in laser & optics, funded by the Center for Innovative Manufacturing (CIM) and Renishaw, investigated laser-based 3D additive manufacturing processes where my work brought new capabilities to model rapid femto-second laser melts and cooling on metal surfaces. This extended existing SPH work to model rapid thermal liquidification and subsequent solidification of metal melts by incorporating the localised thermodynamic process. Its influence on the dynamic changes in material fluid properties and melt surface tension interactions, planarises micro-scale patterned surfaces to deliver high fidelity finishes on prosthetic devices suitable for bio-medical implant applications. 

Industry Innovation and Consultancy

My expertise in the area of CFD and fluid rheology has attracted industry funded projects, primarily from the energy sector. In a consultation project with Chevron to investigate cement well-bore annulus formation, I led and supervised the development of bespoke predictive models and solutions using CFD, highlighting non-Newtonian rheology interplay and mixing between cement, drilling mud and spacer fluids during well-bore construction. The effects of annulus eccentricity with varying drill angles, from vertical to horizontal well-bores, were analysed and results were successfully validated against experimental ones. The developed models were subsequently employed to inform well-bore annulus construction and drilling operations.

In a project with Proserv, I co-led an inter-disciplinary team to provide mathematical and computational modelling expertise to enhance understanding and development of new technologies for inspection, repair and maintenance of fixed and floating offshore infrastructures. In particular, cleaning for bio-fouling removal of marine growth using high pressure underwater jets has led to the development of innovative solutions for novel high pressure nozzle designs to reinforce deep-sea jetting performance and efficiency. 

I was successful in winning research and industrial project proposals with the Oil & Gas Innovation Centre (OGIC) which accelerated the pace of technology development for the oil and gas industry. The collaborative research project co-funded by Phoenix RDS, a specialist upstream oil & gas subsurface consultancy company, developed innovative solutions to enhance oil recovery from reservoirs. I led the research team that brought together expertise from the petroleum institute and mechanical engineering disciplines to analyse and optimise well polymer flood injections into reservoir workflows and large-scale reservoir simulations for maximising oil extraction. A detailed investigation was also conducted to advance original mechanical designs of polymer-friendly flow control devices (FCD) by considering the changes in fluid rheology using CFD; a successful proof of concept FCD prototype was developed to reduce mechanical degradation of polymer flows and its performance was validated experimentally in small and full-scale tests.

Current Research

Presently, my research focuses on advancing and pushing the boundaries of fundamental science governing thermo-fluid systems while challenging traditional numerical methodologies to better model and understand complex fluid behaviour and their interactions with the environment.

Marine & Environmental Life Sciences

Recent collaborative work in the area of marine and environmental life sciences have expanded my research capabilities in modelling evolution (proliferation, death and dissolution) of reef-forming corals; the corals are reliant on optimal flow current conditions for the provision of organic materials/preys, while in their absence, die out. In addition, the dissolution of the coral weakens its structure and caused breakage which then alters the hydrodynamics of surrounding flows. Computational modelling using particle-based SPH approach is employed for the first time to engineer coral habitat and its predictive capabilities are rigorously demonstrated through data from the literature and experiments. 

Colloidal Suspensions

Similarly, my interest in the fundamentals of thermo-fluids has piqued my fascination in novel nano-particle laden ferro-magnetic fluid research with the aim to explore thermo-magnetic fluid response to alternating magnetic fields. A set of sinusoidal varying frequencies is used to control heat-transfer characteristics, and therefore generating forced thermo-magnetic convection in cavity cells that lead to potential engineering applications in aerospace, micro-/nano-fluidics and bio-medical devices; the technology negates the need for mechanical components to drive fluid flow while facilitating active heat transfer. 

Renewable Energy

Lastly, my research in fluid dynamics mirrors my belief in the importance for sustainable energy alternatives. Working together with multi-disciplinary collaborators in renewable energy, computational modelling is employed to investigate and improve performance of floating offshore wind turbines. Surge motion of floating wind turbine can lead to propeller-like conditions or vortex ring states, that in turn, has an impact on turbine aerodynamic performance. The research aspires to provide better insights and demonstrates the causes of propeller and vortex ring states of offshore floating turbines.

Keywords:

• Computational fluid dynamics
• Multi-phase flows
• Free-surface flows
• Soft matter liquids
• Interfacial flows
• Thin liquid films
• Rivulets
• Droplets
• Sprays
• Coating
• Rheology
• Marangoni effects
• Wetting and de-wetting contact lines
• Mixing and sloshing
• Splat morphologies
• Cold and thermal sprays
• Laser spots and melts
• Evaporation of liquids
• Solidification of liquids and phase change of crystal structures
• Porous media flow
• Ferro-magnetic fluids
• Continuous oscillatory baffled reactors
• Marine biology - tropical and cold water corals and coralline algae
• Homogenisation and upscaling
• Non-linear partial differential equations
• Multigrid methods and convergence acceleration
• Minimisation and optimisation
• Adaptive local mesh refinement
• Adaptive time integration
• Smoothed particle hydrodynamics
• Algorithms
• Machine learning and evolutionary algorithms
• High performance computing

Other research

Keywords:

• Task-based parallelisation
• Lossless compression
• Convergence and stability of meshless methods
• Eulerian & Lagrangian methods
• Inverse methods
• High order PDEs

Research degrees awarded to supervised students

Supervised 16 Ph.D. research student projects spanning across a range of applications in engineering, physical and biological sciences. Successfully graduated 13 Ph.D. research students while the remaining 3 are at various stages of completion.