My research group conducts fundamental research in interfacial fluid mechanics, transport phenomena, and multiphase flows with many applications; these range from process intensification, surfactant-replacement therapy, crude-oil and food processing, coating flow technology, manufacturing of pharmaceuticals, pipeline transportation of crude oil, distillation, to microfluidics and nanotechnology.
The Multi-scale Exploration of MultiPHase physIcs in flowS (MEMPHIS) is a £5m Engineering and Physical Sciences Research Council (EPSRC) Programme Grant. This project, led by OKM, is a collaboration between Imperial, Birmingham, Nottingham, and UCL to create the next generation modelling tools for complex multiphase flows. The Programme will achieve this goal by developing a single modelling framework that establishes a transparent linkage between input (models and/or data) and prediction, optimal selection of massively-parallelisable numerical methods, capable of running efficiently on 105-106 core supercomputers, optimally-adaptive, three-dimensional resolution, and the most sophisticated multi-scale physical models.
The Transient and Complex Multiphase Flows and Flow Assurance (TMF) project is a consortium comprising a number of oil-and-gas companies, software- and design-houses. TMF, led by OKM, was founded by Professor Geoff Hewitt of Imperial College in 1996 and currently there are three university partners: Imperial, Cranfield, and Nottingham. Past and current research themes include the development of world-leading experimental techniques to image multiphase flow regimes and measure their flow characteristics including the use of real fluids e.g. oil and SF60; the development of cutting-edge numerical techniques for faithful simulation of complex, transient multiphase flows; the development of effective, one and two-dimensional models for efficient and reliable computation of large-scale features of multiphase flows and flow regime transitions; elucidating the intricate coupling arising from complexities related to flow geometry and/or heat transfer on the nature of multiphase flows in practical situations.
UNIHEAT crude-oil fouling: The aims of the project (funded by the Skolkovo Foundation) are to achieve fundamental understanding of the transfer processes underlying the development of a fouling layer on the inside of heat exchangers. This involves detailed modelling of the flow field and its interactions with the fouling layer, and of processes, such as bulk and interfacial chemical reactions, which may be responsible for the deposition of the layer. The models developed are based on fluid mechanical and heat and mass transfer principles and account for processes which increase and decrease the average thickness of the fouling layer; these include the direct deposition onto the layer of asphaltenes species and of fouling layer ‘particles’ carried by the flow, and entrainment of these particles via hydrodynamic interactions with the flow, respectively. The flow may be either laminar or turbulent.
Engineering and control of surfactant-laden flows: This project (funded by the EPSRC) will provide detailed understanding of how surfactants behave at contact lines and adsorb at interfaces, and how this ultimately affects the spreading and wetting of hydrophobic surfaces. These factors underlie striking and technologically important, yet poorly eludicated effects, such as superspreading whereby aqueous droplets containing superspreader surfactants (e.g. trisiloxanes) spread rapidly to produce perfect wetting over hydrophobic substrates. This project combines molecular dynamics simulations, continuum-level modelling, and careful experiments. The ultimate objective is the rational design of bespoke surfactant molecular architectures for various applications ranging from agrochemicals to enhanced-oil-recovery. This project is a collaboration with Erich Muller, Richard Craster (IC, Maths), and Victor Starov (Loughborough).
Thin film flows: Our interests are in the dynamics of thin liquid films (or multi-layers) and slender liquid threads and jets (which may be single or compound). A variety of situations are considered in which these films that may have complex rheology are driven by capillarity, marangoni stresses (due to the presence of surfactant concentration and/or temperature gradients), surface and bulk diffusion of chemicals, antagonistic intermolecular forces, gravitational modulation (due to vibration) and electric fields on smooth or patterned substrates, which may be rigid or flexible, impermeable or porous.
Spinning disc reactors for pharmaceuticals and fine chemicals manufacture: Here, the thin liquid film overlying a rapidly spinning disc is subjected to large shear rates resulting in the formation of large amplitude waves with an associated dramatic increase in the rates of heat and mass transfer. This enhancement in mixing conditions can relieve intrinsically fast reactions, which arise naturally in the pharmaceutical and fine chemicals industry that would have otherwise been inhibited by poor mixing conditions in a standard batch operated agitated vessel reactor. This activity can therefore lead to an alternative, small-scale technology, which is of direct relevance to the manufacture of pharmaceuticals and fine chemicals.